1) The study examined the survival of E. coli O157:H7 in commercial cucumber fermentation brines and cucumber juice media under different conditions.
2) The results showed that the time needed for a 5-log reduction of E. coli ranged from 3 to 24 days depending on the pH of the commercial brines, which ranged from 3.2 to 4.6.
3) In laboratory cucumber juice media that had been previously fermented to a pH of 3.9, a 5-log reduction was achieved within 1 to 16 days depending on pH, acid concentration, and temperature.
Effect of some organic acids on some fungal growth and their toxins productionijabjournal
The effect of eight organic acids (propionic, acetic, formic, lactic, tartaric, citric, oxalic and malic acids) as antifungal agents on the growth of four fungi (Aspergillus flavus, Penicillium purpurogenum, Rhizopus nigricans and Fusarium oxysporum) were studied. The high acidity appeared for oxalic acid being 0.14 at the high concentration (10%), while the lowest acidity recorded for propionic acid and acetic acid being 2.71 and 2.56 at the low concentration (5%). It was observed that, there was no relationship between the efficacy of organic acid and its final pH. Acetic acid (10%) has the highest inhibitory effect on A. flavus being 45.21%, but tartaric acid (5%) and citric acid (5%) gave the same lowest inhibition effect (0.42%).
The lowest value of mycelium dry weight (MDW) of P. purpurogenum was 5.92 g/l when acetic acid was
used (10%), but the highest value was 9.38 g/l when tartaric acid (5%) was used. Formic acid (10%) had a
strong effect on the inhibition growth of R. nigricans being 28.65%, similar to propionic acid (10%), acetic
acid (10%), lactic acid (10%), tartaric acid (10%) and citric acid (10%) being 26.57%, 26.38%, 26.19%,
23.53% and 24.48%, respectively. But malic acid (5%) and oxalic acid (5%) were having a week effect on
R. nigricans being 5.31% and 6.45%, respectively. Lactic acid (10%) has the highest inhibitory effect on F.
oxysporum being 34.45% and the lowest value was in the case of tartaric acid (5%) being 1.68%. Four
treatments were used to determine aflatoxin B1 production. The highest inhibition (50%) was observed by
R. nigricans in the presence of formic acid (10%). Acetic acid in 10% level inhibited the toxic secretion of
A. flavus and P. purpurogenum to become 25% and 40%, respectively. Lactic acid (10%) gave 35% inhibition of toxin production in the presence of F. oxysporum.
This study examined the effects of beta glucan as an immunostimulant on the Indian major carp, Labeo rohita, challenged with the bacterial pathogen Aeromonas hydrophila. The experimental groups included: a control group, a group treated with beta glucan, a group treated with beta glucan and challenged with A. hydrophila, and a group only challenged with A. hydrophila. Results showed that beta glucan treatment improved growth performance and boosted hematological and biochemical parameters related to immunity compared to the control and infection-only groups. Specifically, beta glucan increased total erythrocyte count, hemoglobin levels, and improved condition factor and specific growth rate. It also elevated total leukocyte count and different white
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
CHEMICALS AND DRUGS USED IN SHRIMP AQUACULTUREICAR-CIFE
In aquaculture, as in all food production sectors, one of the external inputs required for successful fish production is chemical.
Chemicals are indeed an essential ingredient to successful aquaculture, which has been used in various forms for centuries (Subasinghe et al., 1996).
There is no doubt that some products are very useful, however, may not perform as claimed and farmers must evaluate the cost and benefits of treatment before investing in any products.
Information on how the product works should be studied. Several products have been sold without any explanation of their action.
Other alternatives could be used as bioremediation and use of probiotics, immunostimulants, vaccination, and alternative therapies.
This technical report analyzed antioxidants in fresh and frozen fruits and vegetables stored under varying conditions. Samples of blueberries, raspberries, peas, green beans, cauliflower, and sweetcorn were obtained fresh and frozen from local supermarkets. The fresh produce were stored in a refrigerator at 4°C for up to 3 days, while frozen produce were stored in a freezer at -20°C. The samples were analyzed for vitamin C, total polyphenols, total anthocyanins, β-carotene, and lutein using published analytical methods. In general, antioxidant concentrations in frozen produce resembled fresh produce prior to storage, while refrigerated storage of fresh produce frequently led to decreases in antioxidants to levels
Isolation and Identification of Fungi from fast food restaurants in Langa BazarIJEAB
A total of (218) samples from Eleven different foods were processed between October 2016 and February 2017 which include (Tomato, Chicken meat, red meat, falafel, potato, bread, eggplant, cabbage, celery, cucumber and onion). Samples were collected from 4 different fast food restaurants inoculated on Potato dextrose agar and Sabouraud Dextrose Agar. Isolated fungus identified morphologically and microscopically in accordance with standard procedures. Results showed that six fungal genera were associated with the selected fast food restaurants. The isolated fungal genera were Aspergillus sp., Alternaria sp., Mucor sp., Rhizopus sp., Saccharomyces sp., Brettanomyces sp. The number of total colonies in October were 236 and in February were 119 and the number of colonies were higher when cultured on Potato dextrose agar than Sabouraud Dextrose Agar. There was variation in the pattern of occurrence of the fungus in fast foods Aspergillus sp. appears to be the most pathogenic fungi that present in the food samples.
1) Fruits harvested earlier (OHD-7) recorded the highest antioxidant capacity, while those harvested later (OHD+7) had the lowest.
2) After 15 days of cold storage, fruits harvested on the optimum date (OHD) resisted chilling injury the most (70%), followed by OHD+7 (60%) and OHD-7 (55%).
3) By 30 days, OHD-7 fruits showed no resistance to chilling injury, while OHD and OHD+7 fruits resisted 20% each. All fruits showed no resistance after 45 days. Fruit maturity and storage length significantly influenced chilling injury resistance.
All information regarding which factors involve in food for growth of microorganisms.
Introduction, Food as a substrate for microorganism
a. pH, aw, O-R potential
b. Nutrient Content
c. Accessory food substances
d. Inhibitory substances & biological structure
e. Combined effects of factors affecting growth
Interactions between microorganisms and our foods are sometimes beneficial.
The interactions between microorganisms, plants, and animals are natural and constant.
The ecological role of microorganisms and their importance in all the geochemical cycles in nature.
In most cases microorganisms use our food supply as a source of nutrients for their own growth. This, of course, can result in deterioration of the food. By increasing their numbers, utilizing nutrients, producing enzymatic changes, and contributing off-flavors by means of breakdown of a product or synthesis of new compounds they can “spoil” a food.
This is a normal consequence of the action of microorganisms, since one of their functions in nature is to convert reduced forms of carbon, nitrogen, and sulfur in dead plants and animals to the oxidized form required by plants, which in turn are consumed by animals.
So by simply “doing their thing” in nature they frequently can render our food supply unfit for consumption. To prevent this we minimize the contact between microorganisms and our foods (prevent contamination) and also eliminate microorganisms from our foods, or at least adjust conditions of storage to prevent their growth (preservation).
Effect of some organic acids on some fungal growth and their toxins productionijabjournal
The effect of eight organic acids (propionic, acetic, formic, lactic, tartaric, citric, oxalic and malic acids) as antifungal agents on the growth of four fungi (Aspergillus flavus, Penicillium purpurogenum, Rhizopus nigricans and Fusarium oxysporum) were studied. The high acidity appeared for oxalic acid being 0.14 at the high concentration (10%), while the lowest acidity recorded for propionic acid and acetic acid being 2.71 and 2.56 at the low concentration (5%). It was observed that, there was no relationship between the efficacy of organic acid and its final pH. Acetic acid (10%) has the highest inhibitory effect on A. flavus being 45.21%, but tartaric acid (5%) and citric acid (5%) gave the same lowest inhibition effect (0.42%).
The lowest value of mycelium dry weight (MDW) of P. purpurogenum was 5.92 g/l when acetic acid was
used (10%), but the highest value was 9.38 g/l when tartaric acid (5%) was used. Formic acid (10%) had a
strong effect on the inhibition growth of R. nigricans being 28.65%, similar to propionic acid (10%), acetic
acid (10%), lactic acid (10%), tartaric acid (10%) and citric acid (10%) being 26.57%, 26.38%, 26.19%,
23.53% and 24.48%, respectively. But malic acid (5%) and oxalic acid (5%) were having a week effect on
R. nigricans being 5.31% and 6.45%, respectively. Lactic acid (10%) has the highest inhibitory effect on F.
oxysporum being 34.45% and the lowest value was in the case of tartaric acid (5%) being 1.68%. Four
treatments were used to determine aflatoxin B1 production. The highest inhibition (50%) was observed by
R. nigricans in the presence of formic acid (10%). Acetic acid in 10% level inhibited the toxic secretion of
A. flavus and P. purpurogenum to become 25% and 40%, respectively. Lactic acid (10%) gave 35% inhibition of toxin production in the presence of F. oxysporum.
This study examined the effects of beta glucan as an immunostimulant on the Indian major carp, Labeo rohita, challenged with the bacterial pathogen Aeromonas hydrophila. The experimental groups included: a control group, a group treated with beta glucan, a group treated with beta glucan and challenged with A. hydrophila, and a group only challenged with A. hydrophila. Results showed that beta glucan treatment improved growth performance and boosted hematological and biochemical parameters related to immunity compared to the control and infection-only groups. Specifically, beta glucan increased total erythrocyte count, hemoglobin levels, and improved condition factor and specific growth rate. It also elevated total leukocyte count and different white
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
CHEMICALS AND DRUGS USED IN SHRIMP AQUACULTUREICAR-CIFE
In aquaculture, as in all food production sectors, one of the external inputs required for successful fish production is chemical.
Chemicals are indeed an essential ingredient to successful aquaculture, which has been used in various forms for centuries (Subasinghe et al., 1996).
There is no doubt that some products are very useful, however, may not perform as claimed and farmers must evaluate the cost and benefits of treatment before investing in any products.
Information on how the product works should be studied. Several products have been sold without any explanation of their action.
Other alternatives could be used as bioremediation and use of probiotics, immunostimulants, vaccination, and alternative therapies.
This technical report analyzed antioxidants in fresh and frozen fruits and vegetables stored under varying conditions. Samples of blueberries, raspberries, peas, green beans, cauliflower, and sweetcorn were obtained fresh and frozen from local supermarkets. The fresh produce were stored in a refrigerator at 4°C for up to 3 days, while frozen produce were stored in a freezer at -20°C. The samples were analyzed for vitamin C, total polyphenols, total anthocyanins, β-carotene, and lutein using published analytical methods. In general, antioxidant concentrations in frozen produce resembled fresh produce prior to storage, while refrigerated storage of fresh produce frequently led to decreases in antioxidants to levels
Isolation and Identification of Fungi from fast food restaurants in Langa BazarIJEAB
A total of (218) samples from Eleven different foods were processed between October 2016 and February 2017 which include (Tomato, Chicken meat, red meat, falafel, potato, bread, eggplant, cabbage, celery, cucumber and onion). Samples were collected from 4 different fast food restaurants inoculated on Potato dextrose agar and Sabouraud Dextrose Agar. Isolated fungus identified morphologically and microscopically in accordance with standard procedures. Results showed that six fungal genera were associated with the selected fast food restaurants. The isolated fungal genera were Aspergillus sp., Alternaria sp., Mucor sp., Rhizopus sp., Saccharomyces sp., Brettanomyces sp. The number of total colonies in October were 236 and in February were 119 and the number of colonies were higher when cultured on Potato dextrose agar than Sabouraud Dextrose Agar. There was variation in the pattern of occurrence of the fungus in fast foods Aspergillus sp. appears to be the most pathogenic fungi that present in the food samples.
1) Fruits harvested earlier (OHD-7) recorded the highest antioxidant capacity, while those harvested later (OHD+7) had the lowest.
2) After 15 days of cold storage, fruits harvested on the optimum date (OHD) resisted chilling injury the most (70%), followed by OHD+7 (60%) and OHD-7 (55%).
3) By 30 days, OHD-7 fruits showed no resistance to chilling injury, while OHD and OHD+7 fruits resisted 20% each. All fruits showed no resistance after 45 days. Fruit maturity and storage length significantly influenced chilling injury resistance.
All information regarding which factors involve in food for growth of microorganisms.
Introduction, Food as a substrate for microorganism
a. pH, aw, O-R potential
b. Nutrient Content
c. Accessory food substances
d. Inhibitory substances & biological structure
e. Combined effects of factors affecting growth
Interactions between microorganisms and our foods are sometimes beneficial.
The interactions between microorganisms, plants, and animals are natural and constant.
The ecological role of microorganisms and their importance in all the geochemical cycles in nature.
In most cases microorganisms use our food supply as a source of nutrients for their own growth. This, of course, can result in deterioration of the food. By increasing their numbers, utilizing nutrients, producing enzymatic changes, and contributing off-flavors by means of breakdown of a product or synthesis of new compounds they can “spoil” a food.
This is a normal consequence of the action of microorganisms, since one of their functions in nature is to convert reduced forms of carbon, nitrogen, and sulfur in dead plants and animals to the oxidized form required by plants, which in turn are consumed by animals.
So by simply “doing their thing” in nature they frequently can render our food supply unfit for consumption. To prevent this we minimize the contact between microorganisms and our foods (prevent contamination) and also eliminate microorganisms from our foods, or at least adjust conditions of storage to prevent their growth (preservation).
The document analyzes the depletion of polychlorinated biphenyl (PCB) congeners in fresh Mugil cephelus and sardine fish samples after different cooking treatments. 15 fish samples of each species were collected from markets and analyzed for 10 PCB congeners before and after frying or grilling. Cooking led to depletion levels ranging from 13.6% to 100% across congeners and species. Frying generally led to higher depletion than grilling. The most abundant congeners in fresh fish were PCB 70 and 180. Cooking treatments significantly reduced PCB levels and exposure risk from consuming cooked fish compared to fresh.
ABSTRACT- Fruits and vegetables are the important source in human life. It should be safe and consists of good shelf
life which can improve the level of consumption of fruits and vegetable among the society. The processing is such a great
parameter which analyses the quality of food. Today fruits and vegetables are susceptible to the growth of microorganism
which may be air borne, soil borne and water borne disease. Enzymes offer potential for many exciting applications for
the improvement of foods. There is still, however, a long way to go in realizing this potential. Economic factors i.e.
achievement of the optimum yields and efficient recovery of desired protein are the main deterrents in the use of enzymes.
Changing values in society with respect to recombinant DNA & protein engineering technologies and the growing need to
explore all alternative food sources may in time make enzyme applications more attractive to the food industry
Key-words- Enzyme, immobilization, Screening, Food spoilage, Enzymes, Bacterial contamination, Food poisoning,
Perishable foods
This document summarizes a study that evaluated the probiotic properties of microorganisms isolated from a honey-based kefir beverage. Three strains (Lactobacillus satsumensis LPBF1, Leuconostoc mesenteroides LPBF2, and Saccharomyces cerevisiae LPBF3) were tested for their ability to tolerate acid and bile salts, adhere to epithelial cells, inhibit pathogens, and protect DNA against oxidative damage. All three strains showed resistance to low pH and bile salts, adhesion to cells, and inhibition of E. coli and S. aureus. S. cerevisiae was most effective at protecting DNA against hydroxyl radical damage, likely due to its high antioxidant production.
Final Year Special Research Project (SRP) - Incidence and severity of Differe...KYAW THU WIN
This study examined the incidence and severity of bacterial wilt caused by Ralstonia solanacearum in solanaceous crops like tomato and chilli in three locations in Pyinmana Township, Myanmar. Disease incidence was recorded in field surveys and pathogenicity of isolates from different locations was tested in pot experiments. The isolate from tomatoes in Thar-Yar-Su village showed higher disease severity than isolates from chilli in Thit-Seint-Pin villages both in field surveys and pot experiments, though differences among isolates were not statistically significant. This research provides baseline data on the occurrence of bacterial wilt in the study areas.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document contains summaries of multiple studies related to fungi and plant pathogens. The first study characterized 11 isolates of Trichoderma virens using morphological and molecular techniques, finding a good correlation between the identification methods. The second studied the antimicrobial activity and phytochemical composition of Albiziaamara leaf extracts against bacteria and fungi. The chloroform extract showed the highest activity. A third study evaluated the compatibility of the fungus Nomuraea rileyi with various pesticides, finding several insecticides and fungicides that were most compatible.
The document discusses various factors that influence the growth and activity of microorganisms in food. Internally, key factors include nutrient contents, water activity, pH, redox potential, and osmotic pressure. Externally, temperature is a major influence on microbial growth rates, with psychrophiles, mesophiles, and thermophiles having different optimal temperature ranges. The document also discusses how these various factors affect the heat resistance of microorganisms.
Highlighting Bacillus subtilis GA1 antifungi potentialities for pineapple (An...Innspub Net
Pests, microorganisms and parasites are responsible for significant losses crops and especially fruits and vegetables, which threaten food human. Côte d’ivoire, the first provider of pineapple (Ananas comosus) fresh on European market is facing in recent years to a drastic drop in production to several factors including the action of microorganisms during storage. The struggle Chemical although effective drawbacks. This study aims using the Bacillus subtilis strain GA1 in biological control against germs responsible for alteration pineapple fruit in côte d’ivoire. A sample of twenty-five pineapple which has been used five healthy pineapple and five altered were used for the isolation of microorganisms and fifteen healthy pineapples were used for other tests. The main agents Fungal spoilage isolated pineapple fruit in this work were Aspergillus sp., Rhizopus sp., Fusarium sp., And Candida sp. The pathogenicity tests also confirmed that the isolated fungal strains are responsible for the pineapple fruit rotting. The tests antagonists conducted in the presence of B. subtilis GA1 against fungi isolated showed inhibition rate of 81.2% for Aspergillus sp (s), 69% for Aspergillus sp (a), 64% for Rhizopus sp., and 57.14% for Fusarium sp. protection tests on fruits from biomass of B. subtilis GA1 helped preserve fruits over a period of fourteen (14) days with no mushrooms in the heart of the fruit. Get the full articles at: https://goo.gl/TB0wUg
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This study evaluated the effects of endomycorrhizal fungi and Pseudomonas fluorescens bacteria on the growth, productivity and biochemical properties of cowpea plants under salt stress. The results showed that mycorrhizal colonization of roots decreased as salinity increased. Cowpea plants irrigated with tap water and inoculated with both endomycorrhizae and P. fluorescens exhibited the highest growth in leaf weight, pod length, seed number and protein content. Under higher salt concentrations, inoculation with P. fluorescens led to increased seed weight, while endomycorrhizae inoculation boosted proline, sugar and carotenoid levels in leaves. Thus, the dual
Preservative potentials of crude bacteriocins produced by Lactobacillus tucce...iosrjce
IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB) covers studies of the chemical processes in living organisms, structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules, chemical properties of important biological molecules, like proteins, in particular the chemistry of enzyme-catalyzed reactions, genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction. IOSR-JBB is privileged to focus on a wide range of biotechnology as well as high quality articles on genetic engineering, cell and tissue culture technologies, genetics, microbiology, molecular biology, biochemistry, embryology, cell biology, chemical engineering, bioprocess engineering, information technology, biorobotics.
This document summarizes a study that characterized bacteria isolated from fermented and unfermented coconut. Eight bacterial isolates (3 from fermented, 5 from unfermented coconut) were identified based on biochemical and molecular techniques. Biochemical characterization involved tests for carbohydrate fermentation and other properties. Molecular characterization included PCR amplification of the 16S rRNA gene, BLAST analysis, and multiple sequence alignment. The results identified the isolates as Klebsiella pneumoniae, Enterobacter agglomerans, Pseudomonas spp., Ralstonia pickettii and Burkholderia spp. These species are related to human pathogenicity, indicating the importance of hygiene during food processing and handling of coconut. Proper environmental hygiene is
Relationship between postharvest diseases resistance and mineral composition ...Amílcar Duarte
Green and blue moulds, due to the pathogenic action of Penicillium digitatum and Penicillium italicum respectively are the main cause of orange losses during postharvest. Under Mediterranean climate conditions, both together are responsible for 80% of total postharvest citrus fruit decay. The type of orchard production system, field location with different types of climate and soil has a main influence on mineral composition of fruits. The mineral composition of fruits can have a significant impact on fruit quality and shelf life during postharvest period. These include effects on fruit colour, texture, disease susceptibility, juice composition and development of physiological disorders. Oranges from different regions from South of Spain and Portugal and from three different production systems (conventional, integrated and organic) were studied to evaluate whether both factors (origin and production system) affected the degree of fruit sensitivity to decay. Results indicate that the sensitivity to green or blue mould is determined better by the origin of fruit than by the system of production.
1) The document describes research into using agricultural waste materials like apple pomace and peanut shells to enhance citric acid production through solid state fermentation (SSF) using fungal cultures.
2) Initial screening found that a co-culture of Aspergillus ornatus and Alternaria alternata produced the most citric acid (0.46 mg/mL) when grown on apple pomace.
3) Optimization experiments determined the maximum citric acid yield of 2.644 mg/mL was achieved with the co-culture on apple pomace medium at 50% moisture, pH 5, 25g substrate concentration, and 30°C incubation temperature after 48 hours.
Allium sativum (garlic) has potential as a biological control agent. The document reviews the biology of garlic and studies on its ability to control pests and pathogens. Garlic extracts have shown to inhibit fungal growth and reduce disease severity in tomatoes and downy mildew of cucumbers. Crude garlic extract provided over 90% control of sorghum ergot under greenhouse and field conditions. Results indicate garlic extracts are promising as natural, effective and environmentally friendly alternatives to synthetic pesticides for controlling agricultural diseases and insects.
This study investigated the biochemical resistance mechanisms of Jatropha curcas against Lasiodiplodia theobramae, a leaf blight and necrosis pathogen. Biochemical parameters were evaluated in 8 Jatropha accessions before and after inoculation with the pathogen. The study found that resistant accessions activated the synthesis of defensive compounds like phenolics, flavonoids, proteins, photosynthetic pigments, and salicylic acid. They also increased antioxidant enzyme activities. Susceptible accessions showed decreased photosynthetic pigments and increased lipid peroxidation. Principal component analysis separated resistant from susceptible accessions based on their biochemical parameter profiles, indicating resistance is associated with the induction of defensive biomolecules and oxidative enzymes.
Factors Influencing Growth of Microorganisms in FoodNeeraj Chauhan
The growth of microorganisms in food is influenced by both intrinsic and extrinsic factors. Intrinsic factors include the nutrient content, pH, water activity (aw), and biological structures of the food. Extrinsic factors are relative humidity, temperature, and gaseous environment where the food is stored. Microbial growth is supported by foods that are nutrient-rich, have neutral pH, high aw, and are damaged or processed in ways that allow microbes to penetrate tissues. Relative humidity, temperature that is optimal for the specific microbe, and ambient oxygen levels also impact growth. Understanding these various factors is important for food microbiologists to control spoilage and pathogen growth.
Ps graminis as biocontrol agent of fire blightJorge Gonzalez
☻ Strain 49M of Pseudomonas graminis significantly protected apple blossoms and shoots against fire blight through high efficacy when applied at a concentration of 108 cfu/ml (89.0-82.8%).
☻ Survival of strain 49M bacteria on apple blossoms was high, with 10 days detecting levels of 2.0x104—6.7 x 106 cfu/blossom after introduction at 108 cfu/ml by spraying.
☻ Strain 49M produced siderophores and biofilm but not N-acyl homoserine lactones. It contained the regulatory gen gacA but not genes for selected antibiotics; and inhibited the fire blight pathogen
Alternatives to achieve the sustainability challenge in shrimp production: So...International Aquafeed
Although aquaculture is always referred to as the future solution to feed the nine billion people estimated in world population by 2050, there are still many complications to overcome.
E. coli O157:H7 is a pathogenic strain of Shiga toxin-producing E. coli (STEC) that causes foodborne illness. It was implicated in a large 1993 outbreak linked to undercooked hamburgers from Jack in the Box restaurants that infected over 700 people and killed 4 children. Major sources of infection include undercooked ground beef and contaminated produce. Symptoms range from mild diarrhea to severe complications like hemorrhagic colitis and hemolytic uremic syndrome. Controls and prevention strategies target pre-harvest cattle management, slaughter and processing interventions, thorough cooking of meat, and proper hygiene.
The document summarizes research on the effect of sub-lethal chlorine treatment on the thermal inactivation of Escherichia coli O157:H7 in apple juice. The researcher determined D58 values, which represent the time required to reduce the population by 5 logs, for chlorine-exposed and unexposed E. coli cells in apple juice and buffer. D58 values were higher for unexposed cells compared to chlorine-exposed cells in buffer, indicating chlorine exposure increased heat sensitivity. However, death curves for cells in apple juice were non-linear. Unexposed cells exhibited a delay before inactivation, which chlorine eliminated. Overall, chlorine exposure resulted in loss of thermotolerance in apple juice but
The document analyzes the depletion of polychlorinated biphenyl (PCB) congeners in fresh Mugil cephelus and sardine fish samples after different cooking treatments. 15 fish samples of each species were collected from markets and analyzed for 10 PCB congeners before and after frying or grilling. Cooking led to depletion levels ranging from 13.6% to 100% across congeners and species. Frying generally led to higher depletion than grilling. The most abundant congeners in fresh fish were PCB 70 and 180. Cooking treatments significantly reduced PCB levels and exposure risk from consuming cooked fish compared to fresh.
ABSTRACT- Fruits and vegetables are the important source in human life. It should be safe and consists of good shelf
life which can improve the level of consumption of fruits and vegetable among the society. The processing is such a great
parameter which analyses the quality of food. Today fruits and vegetables are susceptible to the growth of microorganism
which may be air borne, soil borne and water borne disease. Enzymes offer potential for many exciting applications for
the improvement of foods. There is still, however, a long way to go in realizing this potential. Economic factors i.e.
achievement of the optimum yields and efficient recovery of desired protein are the main deterrents in the use of enzymes.
Changing values in society with respect to recombinant DNA & protein engineering technologies and the growing need to
explore all alternative food sources may in time make enzyme applications more attractive to the food industry
Key-words- Enzyme, immobilization, Screening, Food spoilage, Enzymes, Bacterial contamination, Food poisoning,
Perishable foods
This document summarizes a study that evaluated the probiotic properties of microorganisms isolated from a honey-based kefir beverage. Three strains (Lactobacillus satsumensis LPBF1, Leuconostoc mesenteroides LPBF2, and Saccharomyces cerevisiae LPBF3) were tested for their ability to tolerate acid and bile salts, adhere to epithelial cells, inhibit pathogens, and protect DNA against oxidative damage. All three strains showed resistance to low pH and bile salts, adhesion to cells, and inhibition of E. coli and S. aureus. S. cerevisiae was most effective at protecting DNA against hydroxyl radical damage, likely due to its high antioxidant production.
Final Year Special Research Project (SRP) - Incidence and severity of Differe...KYAW THU WIN
This study examined the incidence and severity of bacterial wilt caused by Ralstonia solanacearum in solanaceous crops like tomato and chilli in three locations in Pyinmana Township, Myanmar. Disease incidence was recorded in field surveys and pathogenicity of isolates from different locations was tested in pot experiments. The isolate from tomatoes in Thar-Yar-Su village showed higher disease severity than isolates from chilli in Thit-Seint-Pin villages both in field surveys and pot experiments, though differences among isolates were not statistically significant. This research provides baseline data on the occurrence of bacterial wilt in the study areas.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document contains summaries of multiple studies related to fungi and plant pathogens. The first study characterized 11 isolates of Trichoderma virens using morphological and molecular techniques, finding a good correlation between the identification methods. The second studied the antimicrobial activity and phytochemical composition of Albiziaamara leaf extracts against bacteria and fungi. The chloroform extract showed the highest activity. A third study evaluated the compatibility of the fungus Nomuraea rileyi with various pesticides, finding several insecticides and fungicides that were most compatible.
The document discusses various factors that influence the growth and activity of microorganisms in food. Internally, key factors include nutrient contents, water activity, pH, redox potential, and osmotic pressure. Externally, temperature is a major influence on microbial growth rates, with psychrophiles, mesophiles, and thermophiles having different optimal temperature ranges. The document also discusses how these various factors affect the heat resistance of microorganisms.
Highlighting Bacillus subtilis GA1 antifungi potentialities for pineapple (An...Innspub Net
Pests, microorganisms and parasites are responsible for significant losses crops and especially fruits and vegetables, which threaten food human. Côte d’ivoire, the first provider of pineapple (Ananas comosus) fresh on European market is facing in recent years to a drastic drop in production to several factors including the action of microorganisms during storage. The struggle Chemical although effective drawbacks. This study aims using the Bacillus subtilis strain GA1 in biological control against germs responsible for alteration pineapple fruit in côte d’ivoire. A sample of twenty-five pineapple which has been used five healthy pineapple and five altered were used for the isolation of microorganisms and fifteen healthy pineapples were used for other tests. The main agents Fungal spoilage isolated pineapple fruit in this work were Aspergillus sp., Rhizopus sp., Fusarium sp., And Candida sp. The pathogenicity tests also confirmed that the isolated fungal strains are responsible for the pineapple fruit rotting. The tests antagonists conducted in the presence of B. subtilis GA1 against fungi isolated showed inhibition rate of 81.2% for Aspergillus sp (s), 69% for Aspergillus sp (a), 64% for Rhizopus sp., and 57.14% for Fusarium sp. protection tests on fruits from biomass of B. subtilis GA1 helped preserve fruits over a period of fourteen (14) days with no mushrooms in the heart of the fruit. Get the full articles at: https://goo.gl/TB0wUg
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This study evaluated the effects of endomycorrhizal fungi and Pseudomonas fluorescens bacteria on the growth, productivity and biochemical properties of cowpea plants under salt stress. The results showed that mycorrhizal colonization of roots decreased as salinity increased. Cowpea plants irrigated with tap water and inoculated with both endomycorrhizae and P. fluorescens exhibited the highest growth in leaf weight, pod length, seed number and protein content. Under higher salt concentrations, inoculation with P. fluorescens led to increased seed weight, while endomycorrhizae inoculation boosted proline, sugar and carotenoid levels in leaves. Thus, the dual
Preservative potentials of crude bacteriocins produced by Lactobacillus tucce...iosrjce
IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB) covers studies of the chemical processes in living organisms, structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules, chemical properties of important biological molecules, like proteins, in particular the chemistry of enzyme-catalyzed reactions, genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction. IOSR-JBB is privileged to focus on a wide range of biotechnology as well as high quality articles on genetic engineering, cell and tissue culture technologies, genetics, microbiology, molecular biology, biochemistry, embryology, cell biology, chemical engineering, bioprocess engineering, information technology, biorobotics.
This document summarizes a study that characterized bacteria isolated from fermented and unfermented coconut. Eight bacterial isolates (3 from fermented, 5 from unfermented coconut) were identified based on biochemical and molecular techniques. Biochemical characterization involved tests for carbohydrate fermentation and other properties. Molecular characterization included PCR amplification of the 16S rRNA gene, BLAST analysis, and multiple sequence alignment. The results identified the isolates as Klebsiella pneumoniae, Enterobacter agglomerans, Pseudomonas spp., Ralstonia pickettii and Burkholderia spp. These species are related to human pathogenicity, indicating the importance of hygiene during food processing and handling of coconut. Proper environmental hygiene is
Relationship between postharvest diseases resistance and mineral composition ...Amílcar Duarte
Green and blue moulds, due to the pathogenic action of Penicillium digitatum and Penicillium italicum respectively are the main cause of orange losses during postharvest. Under Mediterranean climate conditions, both together are responsible for 80% of total postharvest citrus fruit decay. The type of orchard production system, field location with different types of climate and soil has a main influence on mineral composition of fruits. The mineral composition of fruits can have a significant impact on fruit quality and shelf life during postharvest period. These include effects on fruit colour, texture, disease susceptibility, juice composition and development of physiological disorders. Oranges from different regions from South of Spain and Portugal and from three different production systems (conventional, integrated and organic) were studied to evaluate whether both factors (origin and production system) affected the degree of fruit sensitivity to decay. Results indicate that the sensitivity to green or blue mould is determined better by the origin of fruit than by the system of production.
1) The document describes research into using agricultural waste materials like apple pomace and peanut shells to enhance citric acid production through solid state fermentation (SSF) using fungal cultures.
2) Initial screening found that a co-culture of Aspergillus ornatus and Alternaria alternata produced the most citric acid (0.46 mg/mL) when grown on apple pomace.
3) Optimization experiments determined the maximum citric acid yield of 2.644 mg/mL was achieved with the co-culture on apple pomace medium at 50% moisture, pH 5, 25g substrate concentration, and 30°C incubation temperature after 48 hours.
Allium sativum (garlic) has potential as a biological control agent. The document reviews the biology of garlic and studies on its ability to control pests and pathogens. Garlic extracts have shown to inhibit fungal growth and reduce disease severity in tomatoes and downy mildew of cucumbers. Crude garlic extract provided over 90% control of sorghum ergot under greenhouse and field conditions. Results indicate garlic extracts are promising as natural, effective and environmentally friendly alternatives to synthetic pesticides for controlling agricultural diseases and insects.
This study investigated the biochemical resistance mechanisms of Jatropha curcas against Lasiodiplodia theobramae, a leaf blight and necrosis pathogen. Biochemical parameters were evaluated in 8 Jatropha accessions before and after inoculation with the pathogen. The study found that resistant accessions activated the synthesis of defensive compounds like phenolics, flavonoids, proteins, photosynthetic pigments, and salicylic acid. They also increased antioxidant enzyme activities. Susceptible accessions showed decreased photosynthetic pigments and increased lipid peroxidation. Principal component analysis separated resistant from susceptible accessions based on their biochemical parameter profiles, indicating resistance is associated with the induction of defensive biomolecules and oxidative enzymes.
Factors Influencing Growth of Microorganisms in FoodNeeraj Chauhan
The growth of microorganisms in food is influenced by both intrinsic and extrinsic factors. Intrinsic factors include the nutrient content, pH, water activity (aw), and biological structures of the food. Extrinsic factors are relative humidity, temperature, and gaseous environment where the food is stored. Microbial growth is supported by foods that are nutrient-rich, have neutral pH, high aw, and are damaged or processed in ways that allow microbes to penetrate tissues. Relative humidity, temperature that is optimal for the specific microbe, and ambient oxygen levels also impact growth. Understanding these various factors is important for food microbiologists to control spoilage and pathogen growth.
Ps graminis as biocontrol agent of fire blightJorge Gonzalez
☻ Strain 49M of Pseudomonas graminis significantly protected apple blossoms and shoots against fire blight through high efficacy when applied at a concentration of 108 cfu/ml (89.0-82.8%).
☻ Survival of strain 49M bacteria on apple blossoms was high, with 10 days detecting levels of 2.0x104—6.7 x 106 cfu/blossom after introduction at 108 cfu/ml by spraying.
☻ Strain 49M produced siderophores and biofilm but not N-acyl homoserine lactones. It contained the regulatory gen gacA but not genes for selected antibiotics; and inhibited the fire blight pathogen
Alternatives to achieve the sustainability challenge in shrimp production: So...International Aquafeed
Although aquaculture is always referred to as the future solution to feed the nine billion people estimated in world population by 2050, there are still many complications to overcome.
E. coli O157:H7 is a pathogenic strain of Shiga toxin-producing E. coli (STEC) that causes foodborne illness. It was implicated in a large 1993 outbreak linked to undercooked hamburgers from Jack in the Box restaurants that infected over 700 people and killed 4 children. Major sources of infection include undercooked ground beef and contaminated produce. Symptoms range from mild diarrhea to severe complications like hemorrhagic colitis and hemolytic uremic syndrome. Controls and prevention strategies target pre-harvest cattle management, slaughter and processing interventions, thorough cooking of meat, and proper hygiene.
The document summarizes research on the effect of sub-lethal chlorine treatment on the thermal inactivation of Escherichia coli O157:H7 in apple juice. The researcher determined D58 values, which represent the time required to reduce the population by 5 logs, for chlorine-exposed and unexposed E. coli cells in apple juice and buffer. D58 values were higher for unexposed cells compared to chlorine-exposed cells in buffer, indicating chlorine exposure increased heat sensitivity. However, death curves for cells in apple juice were non-linear. Unexposed cells exhibited a delay before inactivation, which chlorine eliminated. Overall, chlorine exposure resulted in loss of thermotolerance in apple juice but
The document summarizes the activities of the Deendayal Research Institute for the third quarter of 2012 from October to December. It discusses topics such as using hormonal preparations to regulate estrus in cattle. It also discusses improving the nutritional status of preschool children and conducting field demonstrations on seed treatment in sorghum to improve yields. Video clips were also recorded to document the demonstrations and their effects.
THM et risque de cancer du sein : rôle de la composante progestativeAgnès Fournier
Il est désormais établi que l’ajout d’un progestatif à la composante estrogénique d’un traitement hormonal de la ménopause (THM) constitue un facteur de risque central vis-à-vis du risque de cancer du sein. Si les THM estro-progestatifs ont été officiellement classés comme cancérogènes pour le sein, doit-on considérer qu’ils induisent tous une augmentation comparable du risque, ou que différents THM estro-progestatifs (différentes molécules ou doses, par exemple) comportent des risques différents de cancer du sein ?
Pour répondre à cette question, nous nous sommes basés sur les résultats d’études épidémiologiques évaluant l’impact de différents THM estro-progestatifs sur le risque de cancer du sein.
This document provides guidance for the Clinical Outcomes Publication (COP) program, which publishes quality measures from National Clinical Audits at the consultant, team, and unit level. It covers topics like quality measures, data quality, outlier identification and management, legal considerations, and more. The goal of COP is to improve clinical quality and support transparency by learning from high performers and celebrating excellence. Participating audits are expected to report risk-adjusted mortality as well as additional specialty-specific quality measures of importance to patients.
This holiday greeting card wishes the recipient a merry Christmas and a happy new year, hoping that the season brings happiness, blessings, and prosperity. It also conveys warm wishes for a wonderful holiday season full of love, along with seasonal greetings and best wishes for the coming year of 2015 from the senders.
Outcomes Analysis of E. coli O157:H7 Vaccination in Beef Cattlededmark
The document summarizes research on vaccinating beef cattle against E. coli O157:H7. It finds that vaccination is effective at reducing the pathogen in cattle and potential human illnesses. Mathematical modeling shows that as the efficacy of the vaccine and adoption among producers increases, there are significant reductions in the estimated annual number of human E. coli illnesses, positive regulatory samples, outbreaks from contaminated ground beef, and the occurrence of highly contaminated "hot lots" that could cause illnesses. Even partial adoption of an effective vaccine provides meaningful public health benefits by reducing the prevalence and concentration of the pathogen in the food supply.
The Overview and basic guidance on User interface designing and User experience designing for designer and developers, The Difference in User Interface designing and User Experience Designing.
Effects of low-dose e-beam (student preso)Roppon Picha
The document studied the effects of low-dose, low-penetration electron beam irradiation on Escherichia coli O157:H7 levels and meat quality in beef. It found that treating beef carcass surface cuts with 1 kGy electron beam irradiation reduced E. coli levels by 2.6-2.9 log, eliminating detectable levels. Irradiation had little effect on sensory and quality attributes of flank steaks but did impact ground beef patties more, with higher treatment proportions ranking lower. However, differences may not significantly impact consumer purchase decisions. Overall, low-dose electron beam irradiation showed potential for reducing pathogens on beef surfaces with minimal meat quality impacts.
E. coli O157:H7 is a strain of the bacterium E. coli that can cause severe food poisoning. It is found in the intestines of cattle and other animals. Infection may lead to bloody diarrhea and kidney failure. Most illnesses are caused by eating undercooked, contaminated ground beef. The bacteria can be spread if people do not wash their hands after using the bathroom. An outbreak in Massachusetts in 1991 was traced to fresh-pressed apple cider that was not pasteurized. Washing and brushing apples before pressing and preserving cider can reduce risks. A large 1989-1990 outbreak in Missouri sickened over 200 people and was linked to a municipal water supply that was not properly chlorinated.
Good practices to accelerate agile team knowledge sharing by Mikhail PoduretsLuxoftAgilePractice
Next webinars: http://www.luxoft.com/agile-lean-webinars-schedule
Video: https://youtu.be/LfmCUxfk988
We all are the knowledge workers. When we manage, write code, test code, create architecture or plan the project we work more with our brains rather than with our hands. In this case the availability of knowledge and expertise, the understanding of team members’ experiences, competences and commitments is vital for the project success.
This webinar covers the ways to better knowledge sharing:
* Tacit and explicit knowledge
* Good practices for Agile documentation
* Practices to make knowledge explicit like code review, pair programming and the community of practice
* Information refrigerators and radiators
E. coli O157:H7 is a pathogenic strain of the bacteria Escherichia coli that was first recognized in 1982 during an outbreak linked to contaminated hamburgers. It produces Shiga toxin which can cause bloody diarrhea and potentially fatal complications like hemolytic-uremic syndrome. Common modes of transmission include ingesting contaminated food, water, or contact with ruminant animal feces. Prevention focuses on proper hygiene like handwashing and thoroughly cooking foods. Between 1982-2002 in the US, outbreaks remained common with over half being foodborne, highlighting the ongoing need for food safety regulations and precautions.
JFS#2 final before print 10-9-15 jfds13139_Rev (1)Jane Caldwell
Mitochondrial DNA (mtDNA) fragmentation was assessed in acidified foods using quantitative PCR (qPCR). Ct values from cucumber mtDNA at different processing stages and storage times were significantly different, indicating mtDNA fragmentation from low temperature (75C for 15 min) processing in acidic conditions (pH 3.8). Pasteurization of tomato serum at 95C for varying times highly correlated Ct values to time-temperature treatment. Longer qPCR amplicons provided greater sensitivity to differentiate heat treatments. MtDNA fragmentation is a potential tool to characterize low temperature (<100C) high acid processes, fermentations, and storage of acidic plant products.
This document is a thesis presented by Nikhil Taduka to fulfill the requirements for a Master of Science degree from the University of Wolverhampton. The thesis investigates the inhibitory efficacy of nisin, a bacteriocin produced by Lactococcus lactis, against various foodborne pathogens and spoilage microorganisms, including S. aureus, L. innocua, and E. coli. A variety of techniques are used to test nisin's efficacy at different concentrations, including minimum inhibitory concentration assays, Miles and Misra tests, well inhibition tests, spiral plating, and a Bioscreen C method. The results show that higher nisin concentrations are more effective against gram-positive bacteria, while gram-negative
Hurdle technology in fish preservationShubham Soni
Hurdle Technology is a kind of combination of Mechanisms to preserve the perishable commodity like Fish and the Fish Products, its even useful in other Industries like Poultry, Agri-Industries etc.
Just Keep Creating Hurdles for Microbes and we all we have a healthy and Hygienic Life...!
This document reviews strategies for producing probiotic non-dairy products and evaluating their health benefits. It discusses using fruit juices as a matrix for probiotic microorganisms and describes studies processing probiotic mango and mixed berry juices. Major factors affecting probiotic survival in juices are addressed, along with strategies like fortification with prebiotics, microencapsulation, adaptation, and continuous fermentation technologies. The viability of probiotics in food products depends on maintaining concentrations of 106-107 CFU/g at consumption.
This document summarizes Farah Kanj's senior presentation on food preservation methods. It discusses various preservation techniques including pickling, canning, freezing, biopreservation, and use of nitrates/nitrites. For each method, it provides a description, advantages, and limitations. Additional sections cover conditions for food spoilage and world trends in food science like new technologies and biological risks. The presentation aims to explain different preservation processes and their impact on extending shelf life and food safety.
The study tested aquaponic lettuce and water from Ithaca College's aquaponics system against conventionally grown lettuce to compare microbial safety. Samples were tested for generic E. coli, E. coli O157:H7, and Salmonella. Results showed all aquaponic samples had acceptable E. coli levels below standards, while one store-bought sample exceeded standards. All samples tested negative for E. coli O157:H7 except one tilapia that tested positive for Salmonella, likely from human contact. Overall, the aquaponic produce and water showed lower microbial risks than conventional soil-grown lettuce, though larger studies are needed to make definitive conclusions about food safety.
This document provides information to fruit and vegetable growers on how to make their produce safer for consumers through implementing good agricultural and handling practices. It discusses identifying and managing potential sources of microbial contamination on the farm such as water, manure, workers and equipment. Proper documentation of food safety procedures and recall plans are also emphasized. The goal is to educate growers on reducing risks throughout the growing and harvesting process to protect public health.
Fermented foods have long been consumed by humans and provide health benefits beyond basic nutrition. A review discusses how fermentation transforms food constituents in ways that are beneficial, produces metabolites and proteins with health effects, and provides living microorganisms to the gut. Specifically, fermentation can increase bioavailability of nutrients, produce bioactive peptides and fatty acids, and reduce anti-nutrients and allergens. Limited clinical studies show fermented foods may reduce risk of diabetes, obesity, cardiovascular disease and overall mortality when consumed regularly. The microbes and their byproducts in fermented foods may alter glucose metabolism, support immune function and influence brain activity.
This document discusses food preservation through the use of combined or hurdle methods. Some key points:
- Combined preservation methods use multiple preservation factors (called hurdles), which together inhibit microbial growth through additive or synergistic effects. This allows for gentler processing that maintains sensory and nutritional properties.
- Important hurdles include water activity, pH, redox potential, preservatives, and competitive microflora. Shelf-stable products (SSPs) rely on mild heat combined with reduction of one or more hurdles like water activity or pH to prevent microbial spoilage without refrigeration.
- The concept of hurdle technology involves intelligently combining hurdles to ensure microbial stability as well
Food microbiology is the study of microorganisms that are present in foods and can affect food quality and safety. Microbes can be beneficial, neutral, or harmful to humans. Foods provide excellent nutrients to support microbial growth. There are many factors that affect microbial growth in foods, including intrinsic factors like pH, moisture content, and nutrients as well as extrinsic factors like temperature, relative humidity, gases, and time. Microbial spoilage of foods is evidenced by changes in appearance, texture, odor, and flavor and is caused by bacteria, molds, and yeasts growing in the food.
Bacillus coagulans is a spore-forming probiotic bacterium that is heat-resistant and can be used in food production. It has been added to baked goods. Yeast enzymes produced through recombinant methods have food applications. Probiotics like certain Bifidobacteria strains can extend the shelf life of foods like fish and shrimp by inhibiting harmful bacteria. Probiotic bacteria have potential for use in fruit juices and dairy products. They may also improve immune function and help treat conditions like HIV in children by boosting the immune system. Vegetables and fruits can also act as carriers for probiotics. Probiotic survival in foods like ice cream has been demonstrated without affecting sensory properties.
Microbial fermentation By Aneela SaleemAneelaSaleem
This document discusses different types of fermentation processes used in industry. It begins with an introduction and overview of fermentation media and microorganisms. It then describes the main types of fermentation processes - batch, fed-batch, and continuous fermentation - and factors that influence each type such as growth rate and flow rate. The document also covers solid state and submerged liquid fermentations. Important considerations for continuous fermentation are highlighted. Recent advances in fermentation technology are briefly mentioned at the end.
Bacillus cereus is a rod-shaped, Gram-positive, spore-forming bacterium commonly found in soil and foods. It can cause two types of food poisoning - a diarrheal syndrome caused by enterotoxins and an emetic syndrome caused by a preformed toxin. B. cereus grows between 4-55°C and pH 4.5-9.5, producing spores that allow it to survive harsh conditions. While usually a mild foodborne illness, prevention focuses on proper cooking and refrigeration to limit growth and toxin production in foods.
Advances In Minimal Processing Of Fruits And Vegetables A ReviewSean Flores
This document provides an extensive review of advances in minimal processing of fruits and vegetables. It discusses the production chain from raw material selection to consumption, highlighting aspects like food safety issues. Minimal processing increases perishability by inducing mechanical injury that changes physiology and accelerates deterioration. It can increase respiration and ethylene production rates in some climacteric fruits and vegetables. Proper techniques are needed to preserve quality and extend shelf life, which is generally limited by changes in sensory properties rather than microbial growth. The review aims to inform future research directions to resolve issues limiting quality and shelf life of fresh-cut produce.
Antimicrobial Drug Synthesis from Submerge Cultures of Pleurotus florida in D...iosrjce
IOSR Journal of Pharmacy and Biological Sciences(IOSR-JPBS) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of Pharmacy and Biological Science. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Pharmacy and Biological Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Microbiological Quality Analysis : Isolation,Identificatin and Detection of B...Radheshyam sinha
This document provides a summary of a training report on microbiological quality analysis of drinking water and food. It includes:
1. An overview of the organization that conducted the training (FARE Labs) and their objectives in analytical testing and R&D.
2. An introduction to the importance of food and water testing laboratories in protecting public health and operating as the first line of defense against foodborne illness.
3. Details of the scope, aims, and objectives of the training which focused on understanding food testing laboratories and identifying problems of food contamination by microorganisms.
4. An outline of the methodology, conclusion, and bibliography covered in the full training report.
Institution of Prosecution against the Act of Transporting In a Vehicle a Bul...Agriculture Journal IJOEAR
—Storage temperature plays a major role in causing changes in quality and safety of poultry meat. Product should retain its desired sensory, chemical, physical, functional and microbiological characteristics. Authorized Officers are expected to guide and inspect on food safety and security measures of the country. After conducting comprehensive food outlet inspections covering the whole Medical Officer Health (MOH) area and legal prosecutions over violation of law related to food safety, inspections of food transporting vehicles were conducted. Twenty vehicles were inspected and 7 out of them were released after giving strict advice, 3 were detained to produce before courts. By entering a plea of guilty, first two defendants were admitting their guilt and fined 67 USD each. Last case was charged against the chicken company transporting chicken at temperature of +5 0 Centigrade (standard-18 0 Centigrade), where company lawyer admitted a plea of guilt, but pleaded to release all chicken worth of 2700 USD. Usually in Sri Lankan context, temperature of container was measuring by thermometers as a spot reading of whole passage of cold chain of frozen foods. Upon the expert opinion and scientific explaining by the MOH of the impact of releasing this bulk of chicken on the health of the general public, the Magistrate made decision against the company with strict advice to maintain all vehicles in good sanitary condition, fined 67 USD and ordered to destroy the entire bulk quantity of chicken worth 2000 USD under the supervision of the MOH. This would set future reference/ benchmark in field of food safety in Sri Lanka to supervise and examine of temperature record by Authorized officers using smart phones on data lodgers, which records should be maintained by all frozen food companies thorough out their cold chain, and it can be used as weighted and firm evidence for their legal submissions in future as a complete reflection of cold chain. Keywords— Shelf life, food safety, enactment of food act, poultry meat, unhygienic transport, public health legislation.
WHAT IS SPOILAGE? • Spoilage is the process in which food deteriorates to the point in which it is not edible to humans or its quality of edibility becomes reduced OR • Any change which renders a product unacceptable for human consumption. • Complex event in which a combination of microbial and biochemical activities may interact. • One of the major reason that led to preservation.
FACTORS DETERMINING THE SPOILAGE • Microbial colonization depends on – characteristics of product – The way processed – The way stored • Factors are characterized into four: – Intrinsic parameters – Extrinsic parameters – Modes of preservation and processing – Implicit parameters
INTRINSIC PARAMETERS • Physical, chemical and structural properties. • Inherent in the food itself. • Important factors include water activity, acidity, redox potential, available nutrients and natural antimicrobial substances. EXTRINSIC PARAMETERS • Factors in the environment where food is stored • Temperature, humidity and atmosphere conditions.
MODES OF PRESERVATION AND PROCESSING • Physical or chemical treatment • Change characteristics of food product • Determine the micro flora associated with the product IMPLICIT PARAMETERS OR MICROBIAL INTERFERENCE • These are the result of the development of synergistic or antagonistic microbes • It can be said as the destruction of one organism by another species releasing H2 O2 , bacteriocin and other di-acetyl compounds.
• Synergistic: Production or availability of essential nutrients due to the growth of certain organisms, which allow the growth of another group which were otherwise unable to grow. • Antagonistic : Competition for essential nutrients, changes in pH value or redox potential or formation of antimicrobial substances.
TYPES OF SPOILAGE Two types of Spoilage: • Microbial spoilage • Non- Microbial Based on rate of spoilage: • Highly perishable – Meat, fish, poultry, eggs, milk, most fruits and vegetables. • Semi perishable – Potatoes, some apple varieties, nutmeats • Stable or non-perishable – Sugar, flour, dry beans
SPOILAGE OF FRUITS AND VEGETABLES • The organism responsible for taints are acid tolerant bacteria: – Lactobacillus spp. • Deterioration can be caused by action of animals, birds, bruising, wounding, cutting, freezing, dessication or other mishandling and growth of microorganisms; environmental conditions, contact with spoiled foods. • Microbial spoilage maybe due to: – Plant pathogens acting on stems, leaves, flowers or roots – Saprophytic organisms
• Types of spoilages: – Bacterial soft rot • Caused by Erwinia carotovora, ferment pectins • Pseudomonas marginalis, Bacillus and Clostridium cause water soaked appearance, a soft, mushy consistency and bad odour. – Anthracnose • Caused by Collectotrichum lindemuthianum. • Spotting of leaves and fruits – Black mold rot • Caused by Aspergillus niger • Dark brown to black masses of spores of the mold termed as smut
• Rhizopus soft rot – Caused by species of Rhizopus – Soft and mu
Bioprocess development for enhanced spore production in shake flask and pilot...iosrjce
1) The document describes a study that optimized the production medium and cultivation conditions for enhanced spore production of Bacillus thuringiensis var. israelensis in shake flasks and a 16-L bioreactor.
2) In shake flask experiments, the maximal cell dry mass was 4.26 g/L at 36 hours and maximal spore production was 3.29×106 spores/mL.
3) In the 16-L bioreactor under uncontrolled pH, the maximal cell dry mass was 4.14 g/L at 36 hours and maximal spore production was 3.7×106 spores/mL, representing increases of 23% and 47% respectively over the controlled pH
This study examined the presence of Borrelia burgdorferi, the bacterium that causes Lyme disease, in blacklegged ticks and rodents across five sites on the Outer Banks of North Carolina over an 18-year period from 1991 to 2009. B. burgdorferi was detected in questing blacklegged ticks and isolated from white-footed mice, rice rats, and marsh rabbits sampled at the sites. Sequence analysis confirmed the isolates were B. burgdorferi sensu stricto. The long-term detection of the bacterium across multiple years and locations indicates it is stably transmitted between ticks and rodent populations in this region.
This document discusses superoxide dismutases (SODs) in the bacteria Azotobacter chroococcum and Azotobacter vinelandii. It finds that:
1) A. chroococcum and A. vinelandii only contain iron-containing SOD and copper-zinc SOD, and do not contain manganese SOD.
2) Genomic DNA analysis using sodA- and sodB-specific primers only produced a product for sodB, and not sodA, disputing a previous report that A. chroococcum contains manganese SOD.
3) The results confirm previous findings of iron SOD and copper-z
This document describes a study that developed and validated a multiplex real-time PCR assay to distinguish between human, bovine, and swine fecal contamination in water samples. Species-specific primers and probes were created to target the NADH dehydrogenase subunit 5 (ND5) gene in the mitochondrial DNA of each species. The assay was able to correctly identify the species in spiked effluent samples 83% of the time with no false positives. Some carry-over mitochondrial DNA signal was detected in human feces after consuming beef but not pork products. The multiplex real-time PCR provides a promising new tool for identifying the source of fecal contamination in environmental samples.
This document describes a study that used real-time PCR to detect and quantify mitochondrial DNA from various animal species in domestic wastewater influent from two municipal wastewater treatment facilities over a 24-week period. Human and dog mtDNA were detected in all samples, while bovine, swine, cat, goose, and deer mtDNA were detected sporadically at lower levels. Correlations were observed between some mtDNA concentrations and other measured wastewater parameters. The results indicate that real-time PCR analysis of mtDNA can provide a profile of animal sources contributing to municipal wastewaters and could help identify sources of fecal contamination in environmental waters.
This document describes a new species of bacteria, Pectinatus sottacetonis sp. nov., that was isolated from a commercial pickle spoilage tank. The bacterium, strain FSRU B0405T, was identified as a member of the genus Pectinatus based on 16S rRNA gene sequencing and phylogenetic analysis. P. sottacetonis is a strictly anaerobic, Gram-negative, non-spore-forming rod that is motile with distinctive X-shaped movement. Biochemical and physiological characterization differentiated P. sottacetonis from other Pectinatus species. The document proposes P. sottacetonis as a novel species based on its phenotypic and genetic
This document summarizes a study that evaluated mitochondrial DNA (mtDNA) fragmentation as a potential time-temperature integrator for monitoring safety and quality in dry roasted peanuts. MtDNA fragmentation was measured using quantitative PCR (qPCR) and compared to reduction of the Salmonella surrogate Enterococcus faecium and changes in peanut color (Hunter L value) during roasting. While E. faecium reduction curves were highly repeatable, mtDNA fragmentation did not correlate linearly with time at a given temperature. Dissection of individual peanuts also showed differential heating effects depending on peanut part. The researchers determined that mtDNA fragmentation as measured by qPCR was too variable for validation of dry roasted peanut processes but could help evaluate heat penetration through
Mito low acid final JFS#1 10.1111-1750-3841.12937Jane Caldwell
This document describes a new method for monitoring thermal processing of plant-based foods using quantitative PCR (qPCR) to measure fragmentation of mitochondrial DNA (mtDNA). Universal primers were developed to amplify a conserved mtDNA gene (atp1) present in many plants. Using a sweet potato puree model, the increase in qPCR cycle threshold (Ct) values correlated highly with increased time and temperature of thermal processing, as well as reduction of bacterial spores. The kinetics of mtDNA fragmentation were similar to validated microbial indicators. This novel approach provides a rapid, molecular tool for validating and monitoring thermal food processing as an alternative or supplement to traditional microbiological methods.
Biopeptides article for Prog Dairyman 6-12-16Jane Caldwell
This document discusses biopeptides, which are small protein fragments produced during the fermentation of milk by probiotic bacteria. There are several key points:
1) Biopeptides have beneficial physiological effects when consumed, such as reducing stress and lowering blood pressure. They act like hormones or messengers in the body.
2) Fermented milk products like yogurt contain higher concentrations of biopeptides than plain milk due to the fermentation process. These biopeptides can improve mineral absorption and immune function.
3) As populations age, fermented milk products containing biopeptides may become more popular functional foods due to their potential health benefits compared to caffeinated energy drinks.
Abiotics are non-viable bacteria and their fermentation products that can provide health benefits to hosts when consumed. Abiotics offer advantages over probiotics and prebiotics such as longer shelf life without refrigeration, stimulating the immune system through components like peptidoglycan in cell walls, and feeding beneficial gut bacteria through metabolites. Abiotics are also safer options as they cannot mutate, become pathogenic, or transfer antibiotic resistance, and provide benefits through binding toxins and pathogens without host specificity issues of probiotics.
1. M:FoodMicrobiology
&Safety
Survival of Escherichia coli O157:H7 in Cucumber
Fermentation Brines
Frederick Breidt, Jr. and Jane M. Caldwell
Abstract: Bacterial pathogens have been reported on fresh cucumbers and other vegetables used for commercial fer-
mentation. The Food and Drug Administration currently has a 5-log reduction standard for E. coli O157:H7 and other
vegetative pathogens in acidified pickle products. For fermented vegetables, which are acid foods, there is little data doc-
umenting the conditions needed to kill acid resistant pathogens. To address this knowledge gap, we obtained 10 different
cucumber fermentation brines at different stages of fermentation from 5 domestic commercial plants. Cucumber brines
were used to represent vegetable fermentations because cabbage and other vegetables may have inhibitory compounds
that may affect survival. The 5-log reduction times for E. coli O157:H7 strains in the commercial brines were found to be
positively correlated with brine pH, and ranged from 3 to 24 d for pH values of 3.2 to 4.6, respectively. In a laboratory
cucumber juice medium that had been previously fermented with Lactobacillus plantarum or Leuconostoc mesenteroides (pH
3.9), a 5-log reduction was achieved within 1 to 16 d depending on pH, acid concentration, and temperature. During
competitive growth at 30 ◦
C in the presence of L. plantarum or L. mesenteroides in cucumber juice, E. coli O157:H7 cell
numbers were reduced to below the level of detection within 2 to 3 d. These data may be used to aid manufacturers of
fermented vegetable products determine safe production practices based on fermentation pH and temperature.
Keywords: cucumbers, E. coli O157:H7, fermentation brine, fermented vegetables, survival times
Practical Application: Disease causing strains of the bacterium E. coli may be present on fresh vegetables. Our investigation
determined the time needed to kill E. coli in cucumber fermentation brines and how E. coli strains are killed in competition
with naturally present lactic acid bacteria. Our results showed how brine pH and other brine conditions affected the
killing of E. coli strains. These data can be used by producers of fermented vegetable products to help assure consumer
safety.
Introduction
Acid-resistant, vegetative bacterial pathogens can be present on
fresh produce and ingredients that are used in the manufacture
of fermented and acidified foods. The microflora on fresh fruits,
grains, and vegetables can range from 102
to 109
colony form-
ing units (CFU) per gram (Lund 1992; Nguyen-the and Carlin
1994). On pickling cucumbers, the aerobic microflora are usu-
ally between 104
and 106
CFU/g with lactic acid bacteria (LAB)
around 10 to 104
CFU/g (Fleming and others 1995). A variety
of pathogens, including Salmonella and Shigella species, Aeromonas
hydrophila, Yersinia enterocolitica, Staphylococcus aureus, Campylobacter,
Listeria monocytogenes, E. coli, including acid-resistant enterohem-
orrhagic O157:H7, O145, and other pathogenic serotype strains,
MS 20100970 Submitted 8/27/2010, Accepted 12/21/2010. Authors are with
USDA-ARS, SAA Food Science Research Unit, 322 Schaub Hall, Box 7624,
North Carolina State Univ., Raleigh, NC 27695-7624, U.S.A. Direct inquiries to
author Breidt (E-mail: Fred.Breidt@ars.usda.gov).
Paper nr FSR10-21 of the Journal Series of the Dept. of Food, Bioprocessing
and Nutrition Sciences North Carolina State Univ., Raleigh, NC 27695-7624.
Mention of a trademark or proprietary product does not constitute a guarantee
or warranty of the product by the U.S. Dept. of Agriculture or North Carolina
Agricultural Research Service, nor does it imply approval to the exclusion of
other products that may be suitable.
may be present on vegetables that are used in ready-to-eat and
processed foods (Beuchat 1996, 2002; Brackett 1999; Taormina
and Beuchat 1999). Removal of pathogenic and spoilage bacte-
ria from fresh fruits and vegetables prior to processing is difficult.
Biofilms containing bacteria on fruits and vegetables may be more
resistant to sanitizing agents and organic acid treatments than free
or planktonic cells (Kumar and Anand 1998; Bower and Daeschel
1999; Riordan and others 2001; Sapers 2001). Washing proce-
dures with water or chemical sanitizers typically result in only a 1-
to 2-log decrease in bacterial cell numbers, and bacteria may be
protected in inaccessible locations on fruits and vegetables, such as
the core and calyx of apples (Riordan and others 2001). Attach-
ment of bacteria to wounded or cut surfaces, or entry of bacteria
into the interior of fruits and vegetables through stomata may oc-
cur (Daeschel and Fleming 1981; Seo and Frank 1999; Takeuchi
and Frank 2000; Reina and others 2002). As a result of large
scale commercial processing of vegetables, the spread of pathogens
may occur. Disease outbreaks have occurred in some acid foods
such as apple cider and apple juice (Besser and others, 1993; CDC,
1996), which have pH values around 3.7, similar to many acidified
vegetable products.
Acid and acidified foods are defined in the United States Code
of Federal Regulations (21 CFR part 114) as having a pH value
of ≤ 4.6. This is the pH upper limit that prevents Clostridium
botulinum spore outgrowth and neurotoxin production (Ito and
Journal compilation C 2011 Institute of Food Technologists R
No claim to original US government works
M198 Journal of Food Science r Vol. 76, Nr. 3, 2011 doi: 10.1111/j.1750-3841.2011.02045.x
Further reproduction without permission is prohibited
2. M:FoodMicrobiology
&Safety
Survival of E. coli in brines . . .
others 1976). Acidified foods, to which acid or acid food ingredi-
ents are added to lower the pH below 4.6, include pickled vegeta-
bles sold in hermetically sealed (anaerobic) containers. While the
focus of the regulation is to prevent the growth of C. botulinum
and toxin production, 21 CFR part 114 specifies processing of
acidified foods “to the extent that is sufficient” to destroy vegeta-
tive cells of microorganisms of public health significance. Acidified
vegetable products can be heat processed to assure shelf stability
and safety; and the times and temperatures needed for that pur-
pose have been reported (Breidt and others 2005; Breidt 2006),
and a 5-log reduction standard has been adapted by FDA (Breidt
and others 2010). However, up to half of the $1.5 billion per year
pickled vegetable market consists of products that are preserved
without thermal processing, including fermented products, which
are naturally acidified and defined as acid foods.
Low pH (3 to 4) and organic acids in acidified and fermented
vegetable products prevents the growth of bacterial pathogens and
results in pathogen death. These products have an excellent history
of consumer safety, but definitive data are lacking to show that E.
coli O157:H7, L. monocytogenes, and Salmonella enterica will die off
over the range of conditions under which commercial fermenta-
tions occur. Previous research has shown that E. coli O157:H7 is
the most acid resistant pathogen of concern in acidified vegetables,
and for nonheat processed acidified vegetables containing acetic
acid (pH 3.3 or below), the holding times needed to assure de-
struction of this pathogen are 6 d at 10 ◦
C and 2 d at 25 ◦
C (Breidt
and others 2007). No research has been done to determine the
survival of acid-resistant vegetative pathogens in vegetable fermen-
tations. Of particular concern are fermentations conducted under
colder temperatures such as 10 ◦
C, which increases the survival of
E. coli O157:H7 in acid solutions (Breidt and others 2007).
Our research objectives were to determine the survival of
E. coli O157:H7 in sterile, filtered commercial fermentation
brines, in competitive growth with L. plantarum and L. mesen-
teroides in cucumber juice, and in cucumber juice that has pre-
viously been fermented by these LAB. We examined the effect
of temperature, pH, protonated acid concentrations, NaCl con-
centrations, and other factors on the survival of E. coli O157:H7
in these brines. From these data we determined the times and
temperatures needed to assure safety of vegetable fermentations.
Materials and Methods
Preparation of cucumber brines
Size 2B pickling cucumbers (approximately 3.5 cm diameter)
were obtained from a local supplier. Cucumbers were rinsed and
scrubbed in tap water to remove dirt and debris then processed to
slurry in a Waring blender after 1 : 1 dilution in distilled water
(wt/vol). Slurry was frozen at −20 ◦
C for several days or weeks.
To create cucumber juice medium (CJ), slurry was thawed at 4
◦
C overnight and centrifuged in a Sorval RC-5B plus superspeed
centrifuge (Thermo Electron Corp., Asheville, N.C., U.S.A.) at
7.5k (8539 × g) for 20 min. Supernatant was aspirated from the
solids and the medium was sterilized by filtration using a 0.45
micron bottle filter (430514, Fisher Scientific, Suwanee, Ga.,
U.S.A.). Sodium chloride was added to a final concentration of
2%. Fermented cucumber juice (FCJ) was obtained by inoculating
CJ with a single colony of L. plantarum or L. mesenteroides (Table 1)
and incubating at 30 ◦
C for 96 h, followed by centrifugation and
filtration as described previously. Both CJ and FCJ were stored at
4 ◦
C until use. Fermented cucumber brines (approximately
250 mL) at different stages of fermentation were obtained from
commercial sources, sterilized by filtration (0.45 um) and frozen
at −20 ◦
C until use.
Preparation and handling of bacterial cells
A total of 5 enterotoxigenic E. coli O157:H7 strains (B200 to
B204) were grown independently and combined to form an in-
oculation cocktail (Table 1). E. coli strains were grown statically at
37 ◦
C for 16 h in LB broth (Difco, Becton Dickinson, Sparks,
Md., U.S.A.) supplemented with 1% glucose to induce acid resis-
tance. Overnight cultures were centrifuged at 5k (3000 × g) for 10
min, supernatant was removed, then combined and concentrated
10-fold in sterile saline with approximately equal concentrations
of each bacterial culture. The E. coli cocktail was inoculated at
106
, 108
, and 108
CFU/mL for CJ, FCJ, and commercial brines,
respectively. Brines were incubated for the indicated times and
temperatures, and samples (0.5 mL) were removed and diluted
prior to plating with a spiral plater (Spiral Biotech Inc. Norwood,
Mass., U.S.A.) on nonselective LB agar (Difco). After 24 h incu-
bation at 37 ◦
C, colonies were counted with an automated spiral
plate counter (Q-Count, Spiral Biotech Inc.). The lower detection
limit was between 102
and 103
CFU/mL by this method.
For bacterial competition assays in CJ, L. mesenteroides (LA430)
and L. plantarum (LA445) were grown statically at 30 ◦
C for 16 h in
MRS broth (Difco). Cultures were centrifuged and concentrated
as described for E. coli previously and inoculated at 103
CFU/mL
into CJ containing 106
CFU/mL of the E. coli cocktail. Mixed
culture fermentation samples were serially diluted and plated on
MRS agar (Difco), and LB agar followed by incubation at 30
and 37 ◦
C, respectively. We discovered that E. coli does not form
colonies on MRS agar at 30 ◦
C within 48 h, and L. mesenteroides
and L. plantarum will not grow on LB at 37 ◦
C in 24 h, allowing
independent enumeration of the LAB and the E. coli strains.
Biochemical analysis
Samples (2 mL) were withdrawn aseptically at indicated times
for high-performance liquid chromatography (HPLC), pH, and
NaCl concentrations. The pH was determined with an Accumet
AR25 pH meter (Fisher, Atlanta, Ga., U.S.A.). Sodium chloride
concentration was determined by chloride ion titration using sil-
ver nitrate and fluorescein dye indicator (Collier 1936). Organic
acids, sugars, and ethanol concentrations were measured with a
Thermo Separation Products HPLC (ThermoQuest Inc., San Jose,
Calif., U.S.A.) system consisting of a P1000 pump, an SCM100
solvent degasser, an AS3000 autosampler, and a UV6000 diode
array detector (ThermoQuest) (Breidt and others 2004). A Bio-
Rad HPX-87H column, 300 by 7.8 mm (Bio-Rad, Hercules,
Calif., U.S.A.) was used with a differential refractometer (Waters
model 410 Millipore, Milford, Mass., U.S.A.) and a UV detec-
tor (UV6000LP, Thermo Separation Products, San Jose, Calif.,
U.S.A.) for detection of the analytes. Operating conditions of the
system included a sample tray at 6 ◦
C, a column at 65 ◦
C and
Table 1–Bacterial strains.
Strain ID Strain name Previous ID Origin
B0200 E. coli O157:H7 ATCC 43888 Human feces
B0201 E. coli O157:H7 SRCC 1675 Apple cider outbreak
B0202 E. coli O157:H7 SRCC 1486 Salami outbreak
B0203 E. coli O157:H7 SRCC 2061 Ground beef
B0204 E. coli O157:H7 SRCC 1941 Pork
LA430 L. mesenteroides ATCC 8293 Fermenting olives
LA445 L. plantarum MOP3 Fermenting cucumbers
Vol. 76, Nr. 3, 2011 r Journal of Food Science M199
3. M:FoodMicrobiology
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Survival of E. coli in brines . . .
0.03 N H2SO4 eluent at a flow rate of 0.9 mL/min. The UV6000
detector was set to 210 nm at a rate of 1 Hz for data collec-
tion and 2 Hz was used for refractive index data. ChromQuest
version 4.1 chromatography software was used to control the sys-
tem and analyze the data, utilizing the peak heights for quan-
titative integration based on standard solutions with 4 different
concentrations.
Regression analysis
The estimated 5-log reduction times and standard errors
for the estimate were determined from the killing curves us-
ing a linear regression algorithm in MatlabTM
(Matlab Central
http://www.mathworks.com/matlabcentral/, F. Breidt and J. A.
Osborne). Regression analysis to determine correlations between
pH, protonated acid, and the predicted 5-log reduction time was
carried out using SigmaPlot software (version 10, Systat Software
Inc., Chicago, Ill., U.S.A.).
Results
A total of 10 commercial brines obtained during the first week
of fermentation were found to have pH values ranging from 3.2
to 4.5, and lactic acid concentrations of 150 mM to nondetectable
levels (less than 1 mM) (Table 2). The average NaCl concentration
for these brines was approximately 6.8%, ranging from 5.5% to
8.7%. All brines contained acetic acid, an occasional additive
to commercial brines to help lower the initial pH, encourage
the growth of LAB, and buffer the fermentation. The survival of
the E. coli O157:H7 cocktail in the filtered commercial brines
is shown in Figure 1. The survival curves were approximated by
linear models, with an average R-squared value of 0.876 (data not
shown). From these data, 5-log reduction times were estimated
and the standard error of the estimate determined (Table 2). Sam-
ple A1, which had the highest pH value (4.53), no detectable
lactic acid, and a NaCl concentration of 7.9%, had the highest
5-log reduction time, requiring 22.6 ± 1.3 d at 23 ◦
C.
The 5-log reduction times were used to identify correlations
with brine components. We found a correlation between the pH
of the brine and the 5-log reduction time, with a R-squared value
of 0.71 (Figure 2). A similar trend was found for the correlation
between the log of the protonated acid concentration (calculated
from the Henderson–Hasselbalch equation) and pH, which had
a R-squared value of 0.704 (data not shown). One outlying data
point, brine sample E5, had a relatively short 5-log reduction
time (2 d) but a relatively high pH (3.78) compared to the other
samples. The NaCl concentration for this sample was higher than
the mean for the other samples (7.82% against 6.5%). Although
2 other samples had higher salt concentrations, they also had the
highest pH values for 10 brine samples.
To determine how competition with LAB would affect survival
of the E. coli O157:H7 strains, CJ fermentations were carried
at 30 ◦
C with 2% NaCl. In fermentations with L. mesen-
teroides, the cell numbers for the E. coli O157:H7 strains initially
increased to over 108
CFU/mL but then was reduced to below
Time (days)
0 2 4 6 8 10 12 14 16 18 20 22 24
2
3
4
5
6
7
8
LogCFU/ml
Figure 1–Survival of E. coli O157:H7 in brine from commercial fermenta-
tions at 23 ◦
C under anaerobic conditions. The survival of E. coli O157:H7
strains in brines labeled as shown in Table 1: A1, (filled circle); A2, (filled
triangle up); B1, (filled triangle down); B2, (filled square); C1, (filled dia-
mond); D1, (filled hex); E1, (open triangle up); E2, (open square); E5, (open
diamond); E6, (open hex). The regression lines for A1 data (solid line, R2
=
0.977) and E5 data (dashed line, R2
= 0.881) are shown.
pH
3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6
FiveLogReductionTime(days)
0
3
6
9
12
15
18
21
24
A 1
A 2
B 1
B 2
C 1 D 1
E 1
E 2
E 5
E 6
Figure 2–Five log reduction times and pH of commercial brines at 23 ◦
C
under anaerobic conditions. The alpha-numeric code for each data point
corresponds to the code in Table 1. The error bars represent the stan-
dard error for the calculated 5 log reduction times. The R2
value for the
regression line was 0.71.
Table 2–Biochemistry and 5 log reduction times for commercial brines.
Company IDa
pH NaCl (%) Lactic acid (mM) Acetic acid (mM) 5 log reduction (d) SEb
A1 4.53 7.90 0.00 11.76 22.6 1.3
A2 4.22 8.70 0.00 14.98 18.8 1.1
B1 3.89 5.50 35.81 4.39 13.4 1.7
B2 3.45 6.30 42.41 4.19 9.3 1.7
C1 3.87 6.90 24.86 22.83 15.7 1.7
D1 3.99 6.00 0.36 27.31 15.7 3.0
E1 3.92 5.64 31.89 20.06 15.1 3.1
E2 3.16 6.95 150.76 34.00 3.4 0.8
E5 3.78 7.82 50.60 14.20 2.0 0.7
E6 3.61 6.23 50.17 19.30 8.0 1.9
a
Company ID = company identification code.
b
SE represents the standard error of the estimated 5 log reduction time.
M200 Journal of Food Science r Vol. 76, Nr. 3, 2011
4. M:FoodMicrobiology
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Survival of E. coli in brines . . .
detectable levels (less than 102
CFU/mL) in less than 2.3 d (55 h)
(Figure 3A). During this time, the L. mesenteroides culture grew
from approximately 103
to 107
CFU/mL. In control fermentations
with the E. coli O157:H7 cocktail or the L. mesenteroides culture
grown independently of each other, the cultures grew similarly
within the first 10 to 20 h (to > 108
CFU/mL), but E. coli strains
maintained viability (approximately 107
CFU/mL) during the
55 h of the experiment (Figure 3B). Similar results were seen with
the L. plantarum culture in competition with the E. coli O157:H7
cocktail of strains (Figure 4A and 4B), except the E. coli culture
was reduced to below the limit of detection in mixed culture in
less than 48 h. Interestingly, the final pH values for the mixed cul-
ture fermentations with L. plantarum and the E. coli cocktail were
similar to the L. mesenteriodes—E. coli mixed fermentation (pH 4,
data not shown).
The survival of E. coli in brines of CJ previously fermented with
L. plantarum or L. mesenteroides was determined under the same
conditions as the competitive growth experiment (2% NaCl at
30 ◦
C) (Figure 5). The 5-log reduction for the E. coli O157:H7
strain cocktail, as calculated from the slope of the regression
line, was achieved within 4.3 h ± 0.8 h for CJ previously fer-
mented with L. plantarum, but for CJ previously fermented by
L. mesenteroides 15 ± 1.3 h was needed for a 5-log reduction. At
10 ◦
C, the times needed for a 5-log reduction were found to be
3.2 ± 0.5 d or 16 ± 1.4 d for brine fermented with L. plantarum
or L. mesenteroides, respectively.
Time (hours)
0 5 10 15 20 25 30 35 40 45 50 55
LogCFU/ml
2
3
4
5
6
7
8
9
LogCFU/ml
2
3
4
5
6
7
8
9
Figure 3–Survival of E. coli O157:H7 in competition with L. mesenteroides
at 30 ◦
C under anaerobic conditions. E. coli O157:H7 (triangles) and L.
mesenteroides (squares) cell counts for competitive growth of cells (A) or
cells grown separately (B) in CJ medium. The lines indicating the trends of
growth and death for E. coli O157:H7 strains (solid line) or L. mesenteroides
(dashed line) were 2nd or 3rd order polynomials.
LogCFU/ml
2
3
4
5
6
7
8
9
Time (hours)
0 5 10 15 20 25 30 35 40 45 50 55
LogCFU/ml 2
3
4
5
6
7
8
9
Figure 4–Survival of E. coli O157:H7 in competition with L. plantarum at
30 ◦
C under anaerobic conditions. E. coli O157:H7 (triangles) and L. plan-
tarum(squares)cellcountsforcompetitivegrowthofcells(A)orcellsgrown
separately (B) in CJ medium. The lines indicating the trends of growth and
death for E. coli O157:H7 strains (solid line) or L. plantarum (dashed line)
were 2nd or 3rd order polynomials.
Time (days)
0 2 4 6 8 10 12 14 16 18 20 22 24
LogCFU/ml
2
3
4
5
6
7
8
9
10
Figure 5–Survival of E. coli O157:H7 at 10 ◦
C and 30 ◦
C in brines fer-
mented with L. Plantarum or L. mesenteroides under anaerobic conditions.
SurvivalofE.coli O157:H7infermentedCJ.E.coli O157:H7strains(5-strain
cocktail) were inoculated CJ that had been fermented by L. mesenteroides
(triangles and solid line) or L. plantarum (circles and dashed line). Incuba-
tions were carried out at 10 ◦
C (open symbols) or 30 ◦
C (filled symbols)
The lines depict linear regression for survival in CJ fermented by L. mesen-
teroides (solid line, R2
= 0.82 or 0.96 for 10 ◦
C or 30 ◦
C, respectively) or L.
plantarum (dashed line, R2
= 0.80 or 0.92 for 10 ◦
C or 30 ◦
C, respectively).
Vol. 76, Nr. 3, 2011 r Journal of Food Science M201
5. M:FoodMicrobiology
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Survival of E. coli in brines . . .
Discussion
Process filings are required for commercial production of shelf-
stable acidified foods in the United States. In addition to main-
taining a pH of 4.6 or below, as required by 21 CFR part 114 to
prevent botulism, manufacturers also achieve a 5-log reduction in
the cell numbers of vegetative pathogens (Breidt and others 2010,
2007, 2005). E. coli O157:H7 has been found to be the most acid-
resistant vegetative pathogen of concern in acidified foods, and a
heat process is typically used to assure safety (Breidt and others
2005, 2007). While fermented foods are exempt from acidified
food regulations, little is known about the rate of killing for acid
resistant vegetative pathogens during fermentation. For cucum-
ber and sauerkraut fermentations, both Gram-positive and Gram-
negative bacteria have been shown to grow during the early stages
(first few days) of fermentation, depending on the initial brine
conditions and temperature (Fleming and others 1995; Plengvid-
hya and others 2007). Currently, most manufacturers of fermented
cucumbers use recycled brine or add acetic acid to the brine, this
can selectively encourage the growth of LAB and accelerate the die
off of enteric organisms. Starter cultures are not typically used in
vegetable fermentations, so the rate of fermentation and competi-
tive growth inhibition of vegetative pathogens can vary depending
on the initial microbiota, temperature, salt and acid concentration,
and brine pH.
This study focused on cucumber fermentations and laboratory
CJ studies because cabbage contains antimicrobial compounds,
which may reduce survival of enteric bacteria in brines (Kyung
and Fleming 1997). In cucumber brine that had been fermented
by L. mesenteroides, E. coli O157:H7 strains required more than
2 wk before a 5-log reduction in cell numbers was achieved.
Interestingly, the E. coli O157:H7 strains did not use significant
amounts of the remaining sugars (10 and 12 mM for glucose and
fructose, respectively) for up to 22 d incubation at 10 ◦
C (Table
3). This indicates the low temperature, external pH, and organic
acids inhibited glycolysis. In competition with L. mesenteroides or
L. plantarum, the E. coli O157:H7 strains initially grew at 30 ◦
C
from 106
CFU/mL to greater than 108
CFU/mL; however, the
LAB strains, which were inoculated in co-culture at approximately
103
CFU/mL were able to predominate in the fermentations,
overcoming the 3-log cycle deficit in initial cell numbers within
approximately 24 h (Figure 3). The final pH values obtained in
the mixed culture fermentations with both L. mesenteroides and L.
plantarum were approximately 4 (data not shown). The growth of
the E. coli strains interfered with the metabolic activity and growth
of the LAB, even though the E. coli strains were killed within 2
to 3 d. The factors influencing competitive growth include the
production of organic acids by both competitive species during
fermentative growth, the reduction in pH, and the utilization of
the main carbon sources as well as other nutrients. Because of the
complexity of these interactions, we used polynomial functions
Table 3—Biochemistry of fermented brines inoculated with
E. coli O157:H7.
Glucose Fructose Lactic Acetic
IDa
Time (h) pH (mM) (mM) (mM) (mM)
FCJ-LM 0 3.70 10.3 n.d. 30.8 24.0
FCJ-LM 24 3.9 10.0 0.0 28.4 23.0
FCJ-LP 0 2.89 10.3 12.8 105.2 0.0
FCJ-LP 24 3.0 9.9 12.0 98.1 0.0
a
ID: FCJ-LM = CJ fermented by L. mesenteroides; FCJ-LP = CJ fermented by L.
plantarum.
to approximate the growth and death curves (Figure 3 and 4).
Further study of mixed culture growth of bacteria and improved
competitive growth models (Breidt and Fleming 1998) may be
used to help determine outcomes of competitive growth.
Brine samples were obtained from 9 different commercial fer-
mentations at 5 different fermentation facilities around the United
States, sterilized by filtration, and used to determine survival of
E. coli O157:H7. The results were similar to the observations
with brines prepared in the laboratory by fermentation of CJ with
L. plantarum or L. mesenteroides (although with lower NaCl concen-
tration, approximately 2%). The data show a striking correlation
between pH and 5-log reduction time. As acid accumulates and
pH is reduced in the brine, the 5-log reduction time is correspond-
ingly reduced. Protonated acid concentrations also correlated well
with 5-log reduction time (not shown). If buffering capacity of
brines and fermentation acid production were similar for the dif-
ferent commercial brines obtained, this result would be expected.
Because pH is much easier to measure then protonated acid con-
centrations, we reported the correlation with pH and 5-log re-
duction times only. Only brine samples were used for this study.
Brine pH and organic acids will rapidly equilibrate between the
brine and the vegetable material in the fermentation (Fleming and
others, 1995). Although the log reduction observed for bacterial
pathogens in the brine was not directly measured using cucumber
fruit, the similar pH and acid concentrations should result in similar
log reduction for cells embedded in and on the vegetable material.
Further research would be necessary to confirm this assumption.
A commercial brine having little or no lactic acid at the start
of fermentation (brine sample A1) had a 5-log reduction time
of approximately 3 wk, compared to 3 d for a fermented brine
with a pH of 3.1 and 150 mM lactic acid (brine sample E2)
(Table 2). Under more favorable conditions (lower temperature)
for the survival of E. coli O157:H7 (2% NaCl, 10 ◦
C with CJ
fermentation by L. mesenteroides, Figure 5), a 5-log reduction at
pH 3.9 required 23 d compared to 16 d for commercial brine
samples at 25 ◦
C with similar pH values (brines C1 and D1,
Table 2). While the trend of increasing survival as temperature is
reduced is similar to that reported by Breidt and others (2007),
further study will be needed to clarify the relationship between
temperature and brine survival of E. coli.
Interestingly, one commercial brine had a 5-log reduction time
that was lower than expected based on pH (brine E5) (Table 2 and
Figure 2). This sample had higher salt (7.82% NaCl) compared
to similar samples (brines E6, C1 with 6.23% and 6.9% NaCl,
respectively), but had a 5-log reduction time at least 6 d shorter
(2 d compared with 8 or 15.7 d). The apparent effect of higher salt
concentration was to increase acid killing, but the there may be
other unidentified factors influencing acid killing, including the
presence of preservatives. Postassium sorbate is sometimes used
in commercial fermentations to prevent the growth of spoilage
microflora, including yeasts (Costilow and Uebersax 1982). But,
in the commercial brines used in this study we found no evidence
of sorbate (<1 mM) by HPLC.
Conclusions
Process filings submitted to FDA for commercial production
of acidified foods have a 5-log reduction standard to assure safety.
While fermented foods are considered acid foods, and are therefore
exempt from acidified food regulations, no published research is
available to determine the survival of E. coli O157:H7 or other
pathogens in these products. Given the most permissive conditions
tested for the survival of E. coli O157:H7 (pH 4.5 for commercial
M202 Journal of Food Science r Vol. 76, Nr. 3, 2011
6. M:FoodMicrobiology
&Safety
Survival of E. coli in brines . . .
brine samples at 23 ◦
C or pH 3.9 with brine fermented by L.
mesenteroides at 10 ◦
C), a 5-log reduction was achieved within
23 d. We also found that pH and 5-log reduction time were
closely correlated for a variety of commercial fermentation brines.
Brine pH values below 3.3 required less than 4 d to achieve a
5-log reduction regardless of temperature (10 ◦
C or higher) with
commercial brines or in active competition with LAB. These data
will help commercial manufacturers assure the safety of fermented
vegetable products.
Acknowledgments
The authors acknowledge Drs. Roger F. McFeeters and Jason
A. Osborne for helpful discussions. We also thank Sandra Parker
for excellent editorial assistance. This study was supported in part
by a grant from Pickle Packers Intl. Inc.
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