Conventional food processing techniques Uma Bansal
its a presentation based on conventional food processing techniques and it contains drying methods also along with freeze drying and concentration and evaporation.
Freezing helps to Inhibit the growth of microorganisms hence help in preservation of foods. So, freezing is a very easy and effective method for the preservation of fruits and vegetables and to retain them for longer duration.
Fruits and vegetables are important sources of vitamins, minerals and dietary fibre. The consumption of fruits and vegetables has increased significantly as consumers have become more health-conscious. Whilst most fruit and vegetables should be eaten fresh, processed fruit and vegetables can be acceptable alternatives.
The major contents of the book are procedures for fruit and vegetable preservation, chemical preservation of foods, food preservation by fermentation, preservation by drying, canning fruits, syrups and brines for canning, fruit beverages, fermented beverages, jams, jellies and marmalades, tomato products, chutneys, sauces and pickles, vegetables preparation for processing, vegetable juices, sauces and soups, vegetable dehydration, freezing of vegetables etc. The book also contains photographs of Production Line & Machinery.
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Agents of food spoilage; enzymes and chemical agents.
The role of microorganisms in food spoilage and organisms associated with deterioration of foods.
The role of temperature in food spoilage.
Conventional food processing techniques Uma Bansal
its a presentation based on conventional food processing techniques and it contains drying methods also along with freeze drying and concentration and evaporation.
Freezing helps to Inhibit the growth of microorganisms hence help in preservation of foods. So, freezing is a very easy and effective method for the preservation of fruits and vegetables and to retain them for longer duration.
Fruits and vegetables are important sources of vitamins, minerals and dietary fibre. The consumption of fruits and vegetables has increased significantly as consumers have become more health-conscious. Whilst most fruit and vegetables should be eaten fresh, processed fruit and vegetables can be acceptable alternatives.
The major contents of the book are procedures for fruit and vegetable preservation, chemical preservation of foods, food preservation by fermentation, preservation by drying, canning fruits, syrups and brines for canning, fruit beverages, fermented beverages, jams, jellies and marmalades, tomato products, chutneys, sauces and pickles, vegetables preparation for processing, vegetable juices, sauces and soups, vegetable dehydration, freezing of vegetables etc. The book also contains photographs of Production Line & Machinery.
Tags
Modern Technology on Food Preservation, Book on Food Preservation, Business plan of dehydration vegetable, Food Freezing, Food Preservation Business in India, Fruits and vegetables preservation business India, Food preservation business plan, Food Preservation by Canning, Food Preservation by drying, Food Preservation by Fermentation and Pickling, Food Preservation by Smoking Process, Food Preservation Using Ozone, Food Preservation How to Dehydrate Fruits and Vegetables, Food Preservatives, Food Processing Industry Opportunities in India, Food Technology book, Freezing food preservation, Freezing of fruits and vegetables, How to start a food preservation business, How to start a Fruits and vegetables preservation business, How to start a food processing unit in India, How to Start Food Processing Business, Methods and Techniques of Fruits and vegetables Preservation, Preservation and Processing of Fruits and Vegetables, Preservation of Bakery Products, Preservation of Food as Sugar Concentrates, Preservation of Fruits and vegetables, Starting a Food Preservation Business, Starting Your Own Preserved Foods Business, Storage Stability of Preserved Foods, Thermal Food Preservation, Thermal processing food preservation, Using Dehydration to Preserve Food, Using Dehydration to Preserve Fruits and Vegetables, Most Profitable Food Processing industry, Agro Based Business Ideas for Startup, How to Start Food Processing Industry in India, Food Processing Industry in India, Most Profitable Food Processing Business Ideas, Food Processing & Agro Based Profitable Projects, Food Processing Projects, Small Scale Food Processing business, Starting a Food or Beverage Processing Business, How to Start a Food Production Business, Agro Based Small Scale Industries, Food processing industries, new small scale ideas in Food processing industry, Setting up of Food Processing Units, how to start a food manufacturing business, Dehydration of Fruits and Vegetables, Canning of Fruits and Vegetables
Agents of food spoilage; enzymes and chemical agents.
The role of microorganisms in food spoilage and organisms associated with deterioration of foods.
The role of temperature in food spoilage.
This chapter more focused on the reduced temperature processes. Therefore, processes like chilling, freezing, freeze drying and freeze concentration as well as modified or controlled atmosphere storage and packaging are the main lessons covered
Food engineering operations are employed in food industries for production of good quality palatable and stable foods.Food engineering operations convert raw agricultural commodities into canned, frozen, dehydrated, formulated and otherwise modified forms of food.
Refrigeration is a technique used for preserving food in low temperatures. This procedure slow down or stop most bacteria from dividing and thereby multiplying, but do not kill them.
Heat application has many benefit for eating quality and sensory properties of many food products. Therefore, this chapter discusses much high-temperature processing such as blanching, pasteurization, sterilization, extrusion, evaporation, dehydration, distillation and rehydration.
Dehydration
food dehydration
preservation effect
controlling factors for dehydration
factors affecting dehydration
driers commonly used are
dehydration and nutritive value
disadvantage
drying and microbes
DEHYDRATION
Chapter 5
INTRODUCTION
Water Activity is related to the amount of water contained in the food material and defines the amount of water that can be used for the growth and reproduction of micro-organisms,
Water is essential solvent that is needed in biochemical reaction in living organism.
FREE WATER VS BOUND WATER
The term water activity defines the degree in which such water molecules are “bound”.
A portion of the total water content present in a food material is strongly bound to specific sites on the molecules that comprise the food material.
FOOD PRESERVATION BY CONTROLLING WATER ACTIVITY
Preservation of many food materials can be achieved by lowering the amount of water available for the growth of micro-organisms.
CONTROLLING BROWNING REACTIONS
Food products are subject to browning reactions.
Dehydrated products are probably more so than others.
FOOD DRYING
Food is dried when water is removed from it.
The oldest and simplest way of water removal is sun drying.
The use of drying equipment heated by gas, electricity or steam is called artificial drying or dehydration.
Another method of drying food is by frying or oil drying.
ADVANTAGES OF DRIED AND DEHYDRATED FOODS
Decrease in weight and bulk
Convenience
Shelf stable
MECHANISM OF DRYING/DEHYDRATION
Two processes:
Heat transfer
Mass transfer
The rate of drying is affected by the following factors:
Humidity
Surface Area
Temperature
Air velocity
Ventilation/ moist air outlet
Atmospheric pressure and vacuum
STAGES OF DRYING
Constant rate period
Falling rate period
CONSTANT RATE PERIOD
At the start of the drying process, the food material is still completely wet.
FALLING RATE PERIOD
As drying proceeds the moisture content falls and the access of water form the interior of the food to the surface.
TYPES OF FOOD TO DRY
Seeds, leaf vegetables and herbs are probably the easiest to dry.
Lettuce, melons, and cucumbers are a few foods that do not dry well by conventional methods.
CASE HARDENING
The higher the temperature and the lower the humidity, the more rapid the rate of dehydration will be, but if drying takes place too fast, “case hardening” will occur.
UNIFORM DRYING
Simple drying equipment do not dry food uniformly.
Key Features of The Italian Restaurants.pdfmenafilo317
Filomena, a renowned Italian restaurant, is renowned for its authentic cuisine, warm environment, and exceptional service. Recognized for its homemade pasta, traditional dishes, and extensive wine selection, we provide a true taste of Italy. Its commitment to quality ingredients and classic recipes has made it a adored dining destination for Italian food enthusiasts.
Piccola Cucina is regarded as the best restaurant in Brooklyn and as the best Italian restaurant in NYC. We offer authentic Italian cuisine with a Sicilian touch that elevates the entire fine dining experience. We’re the first result when someone searches for where to eat in Brooklyn or the best restaurant near me.
Ang Chong Yi Navigating Singaporean Flavors: A Journey from Cultural Heritage...Ang Chong Yi
In the heart of Singapore, where tradition meets modernity, He embarks on a culinary adventure that transcends borders. His mission? Ang Chong Yi Exploring the Cultural Heritage and Identity in Singaporean Cuisine. To explore the rich tapestry of flavours that define Singaporean cuisine while embracing innovative plant-based approaches. Join us as we follow his footsteps through bustling markets, hidden hawker stalls, and vibrant street corners.
At Taste Of Middle East, we believe that food is not just about satisfying hunger, it's about experiencing different cultures and traditions. Our restaurant concept is based on selecting famous dishes from Iran, Turkey, Afghanistan, and other Arabic countries to give our customers an authentic taste of the Middle East
Roti Bank Hyderabad: A Beacon of Hope and NourishmentRoti Bank
One of the top cities of India, Hyderabad is the capital of Telangana and home to some of the biggest companies. But the other aspect of the city is a huge chunk of population that is even deprived of the food and shelter. There are many people in Hyderabad that are not having access to
1. Principles of fresh food
storage
G BHARATHI
Assistant Professor
Department of Food and Dairy Technology
2. • Storage life of foods can be prolonged or shortened depending on the
conditions of storage and physical abuse the food products receive
prior to, during and following storage.
• In overall analysis the cool storage of nearly all foods, fresh or
preserved is beneficial to the retention of quality.
3. Nature of harvested crops
• The quality of harvested fruits and vegetables is dependent on the
conditions of growth and on post harvest treatments.
• The climatic factors and cultural practices are complex.
• The length of storage is a function of composition, resistance to attack
microorganisms, the external conditions of temperature, and the gases
in the environment.
• A mature harvested fruit contains a variety of oxidizable substrates and
the molecular machinery required to perform oxidative reactions.
4. • Respiration is the major process of concern and its mechanism is essentially the
same in fruits as in other plant and animal life.
• In fruits, as in other materials, biological oxidations involve a number of metabolic
pathways in which synthetic and degradative reactions are interdependent.
• Ripening in fruit is a critical period of transition from the stages of cell
disorganization and death. Ripening means those changes in sensory factors of
color, texture and taste which render the fruit acceptable to eat.
• These changes may be detected by analyzing transformations in pigments, pectin,
carbohydrates, acids and tannins, etc.
• Climacteric- Stages of the fruit associated with ethylene production and rise in
cellular respiration
5. • Respiration – oxidative breakdown of complex substrate molecules –
starches, sugar and organic acids to simpler molecules- co2 and H2o.
• Events of senescence and ripening – signaled by abrupt changes in
respiration.
• Aerobic respiration-3 complex reaction – catalyzed by a number of
specific enzymes – add an energy containing phosphate group to the
substrate molecule , rearrange the molecule, breakdown the molecule
to simpler one.
• metabolic pathways
• Glycolysis
• Tricarboxylic acid
• Electron transport system
• Pentose Phosphate pathway
8. • After harvest the decline in the rate of oxygen uptake and the CO2 evolution
to a low value is followed by a sharp rise to a peak, termination in a post
climacteric stage.
• The peak to minimum ration tend to increase with temperature.
• This ratio varies among fruits.
• For example, it is much higher for a banana than for an apple.
• Fruit reaches the eating stage at the climacteric peak or sometime after the
peak, depending on the species and conditions of storage.
9. • Unique changes take place during the sharp rise in respiration from the
pre-climacteric minimum to the climacteric peak.
• The slope of the rise varies with species, maturity, temperature and
oxygen and CO2 content of the storage chamber.
• Various anabolic and catabolic reactions are associated with the
ripening of fruit.
• Example: depolymerisation include the hydrolysis of starch to glucose
in the banana and the breaking of polygalacturonic chains of pectin.
• Tissues with vegetative or Floral meristems- asparagus, broccoli- high
respiration rate
• Nuts and tubers – Low respiration rate
10. Climacteric Fruits Non-Climacteric Fruits
Apple Blueberry
Apricot Cherry
Avocado Cucumber
Banana Grape
Fig Grape fruit
Guava Lemon
Mango Orange
12. • A multitude of physiological processes is present in edible plant at the time of
harvest.
• Example: on removal of vegetative parts (fruits, roots, stem) from the parent plant,
the tissues are deprived of their normal supply of water, minerals and organic
molecules( sugars, hormones) which previously translocated to them from other
parts of the plant.
• Although photosynthic activity of the plant is then negligible, most tissues retain
capabilities of a diversity of metabolic reactions which are specific to a given
commodity and variety.
• These are seen in events such as rotting, ripening, sprouting, toughening and
yellowing etc.
13. • The kind and intensity of activity in detached plant parts determines to
a large extent their storage life.
• Seeds, fleshy roots, tubers and bulbs are morphologically and
physiologically designed to maintain the tissues in a dormant
condition until favorable environmental situations are available for
germination and growth.
• Metabolic activity is low but completely halted in such tissues.
• Fruits, leaves and stems – physiologically conditioned for senescence
rather than dormancy.
14. Plant product storage
• Fresh fruits and vegetables maintain life processes during storage so
long as they are alive, they are able to resist the growth of spoilage
microorganisms to some extent.
15. Decay control
• Antimicrobial agents and senescence inhibitors can be used to delay
the onset of spoilage during storage.
• Two methods of applying these agents are
1. a spray or dip in a solution or suspension in water/ wax
formulations and
2. fumigations
17. Heat evolved by living tissues
• Freshly harvested fruits, vegetables and grains are alive.
• These living tissues respire and released energy in the form of heat.
• The amount of heat released varies with the commodity and increases
as the temperature of the storage chamber increases.
• Reducing the rate of respiration could prolong the storage life.
18. Temperature of cold storage rooms
• Temperature control in cold storage rooms is most important.
• Variations from desired conditions may be most damaging.
• These variations can be prevented if the storage rooms are well insulated,
have adequate refrigeration equipment and the spread between the
temperature of the refrigerating coils and the temperature of the storage room
is minimum.
• The difference between the temperature of the refrigerant and the temperature
of the storage room is important in maintaining desired humidity.
20. Metabolism a function of temperature
• The metabolism of living tissue is a function of the temperature of the environment.
• Living organisms have a temperature which is optimum for growth.
• Higher temperatures are injurious.
• Lower temperature greatly retard metabolism.
• Low temperatures near the freezing point of water, are effective in reducing the rate at which respiration
occurs.
• Such temperatures have been found to be valuable in short term preservation of foods.
• For every 10°C the temperature is lowered, it may be estimated that the rate of a reaction will be halved.
• Storage of food at temperatures near 0°C to 5°C may be anticipated to prolong the period in which foods may
be stored.
• Lower temperatures not only decrease the respiration rate but also halt the growth of spoilage
21. • Three types of microorganisms with an optimal temperature for
growth.
Thermophiles
Mesophiles
Psychrophiles
55°C
37°C
<10°C
23. Creating energy deficits
• Ice has been employed since early times to prolong the storage life of foods.
• It is the energy deficit of ice which has great utility.
• When all the energy deficit of ice is supplied, water remains; the temperature of the water food
substrate begins to come into equilibrium with the environment.
• Protective mechanisms may prolong this process by insulation.
• The temperature of the water food substrate reaches that where microorganisms can multiply, the
food will deteriorate very rapidly.
• Ice is therefore used presently where its characteristics are of value.
• One feature of ice in cooling foods is that ice does not desiccate the food.
24. Creating energy deficits mechanically
• One of the important invention of man is mechanical refrigeration.
• Ammonia gas takes up energy as it is expanded.
• This heat is taken from the atmosphere or chamber or environment.
• The expanded ammonia gas is then compressed.
• This requires energy to be exerted on the system.
• The compressed gas is now hot
• Heat is removed from the compressed gas by means of running water or circulating air over the tubes containing
the hot gas.
• The gas is liquefied. The cycle is then repeated. With such a system accurate temperature control is possible. The
refrigeration developed may be made to work directly on the food.
26. Refrigeration load needed
• Refrigeration requirement for a chamber of fruits and vegetables
• Initial temperature of the food
• Final storage temperature
• The rate of respiration and heat evolved
• Specific heat of food
• Amount of food to be placed in the room
• Heat load would be obtained by multiplying the specific heat for the food by the
number of degrees the temperature will be lowered by the weight of food.
• Btu- amount of heat required to raise one pound of water one degree Fahrenheit at
or near the water’s point of maximum density.
• Cooling process- fruits or vegetables live on and evolve heat
27. Specific heat of foods
• The specific heat of food is required in calculating the refrigeration load.
• The specific heat for a food can be estimated from the equation:
• Example: apples have 85% moisture.
• The specific heat of apples can be estimated to be 0.008× 85+0.20 or 0.88
Specific heat = 0.008 (% H2O in food) + 0.20
28. Cold injury to fruits and vegetables
• Fruits and vegetables are susceptible to cold injury at above freezing temperatures.
• There is wide variation in fruits and vegetables in their injury due to freezing.
• Some foods are not injured with a slight exposure to freezing temperatures; other
foods can be frozen and thawed several times without permanent injury.
• Living tissues must be kept living if the food values and eating quality are to be
maintained by cold storage practices.
29. Animal product storage
• Microorganisms causing spoilage of fresh meat, poultry, eggs and
most dairy products have optimum temperature for growth at 20°C to
35°C.
• Pseudomonads –major cause of spoilage for most fresh meats, poultry,
eggs and bulk tank raw milk.
30. Meat
• Most critical factors influencing spoilage rate are temperature and initial level of contamination.
• Small changes in the temperature in the range of 0- 7°C have an effect on refrigerated shelf life of beef,
poultry and pork.
• Coli-aerogens and micrococci are found at vey low levels in spoiled beef held at 4°C.
• These groups increase to moderate levels at 9°C and become a significant portion of the spoilage
population at 15°C.
• Pseudomonads dominate the spoilage flora at all temperatures; with chicken meat pseudomonads
dominate at 1°C and become of less significance as holding temperature increased.
• Acinetobacter and members of the family Enterobacteriaceae are of little consequence at 1°C but
increases significantly with the higher temperatures of 10°C and 15°C.
31. Milk
• The importance of temperature as well as time in holding milk cannot be overstated.
• Manufacturing-grade milk received into a plant with bacterial counts in the millions requires little time
to spoil further.
• This is especially true for milk received at 7°C or more, where the generation time may be only 8hr or
less compared to 12hr at 5°C and 16hr at 2°C. this is due to the psychrotrophic nature of the majority
of bacteria in the milk.
• Coliforms do not rapidly multiply in adequately refrigerated milk.
• Psychrotrophic coli-aerogens bacteria may constitute 5 to 20% of the psychrotrophic microflora of
farm bulk tank milk at time of retailing.
• These may increase only 100 or 1000 fold in 3 days at 3 °C to 5 °C, yet rarely attain dominance in milk
at temperatures of less than 8 °C to 10°C.
32. Eggs
• The spoilage of eggs is also depends upon the degree of refrigeration.
• Tests on raw albumen for 3 weeks at 5°, 10°, 15°C and 20 °C reveal that pseudomonas sp.
Dominate at 5°C and decrease in significance as the holding temperatures approaches 20°C.
• conversely, Enterobacter liquifaciens was not detected at 5°C and increased significantly as
the holding temperatures was raised to 20°C.
• It is clear that temperature markedly influences the rate of spoilage of animal products and
the types of bacteria.
• Environmental temperature influences the types and numbers of bacteria present in a
processing area.
• Aseptic packaging has extended refrigerated shelf life of 6 weeks to 6 months.
33. Storage of eggs
• Eggs should be stored at the lowest temperature possible yet not permit
the interior of the egg to solidify.
• Shell characteristics also affect the storage quality of eggs, as thick shells
withstand the solidification better than thin shelled eggs.
• It is considered that -1°C is the ideal storage temperature for eggs.
• A relative humidity between 82-85% is generally considered optimum for
eggs.
• Eggs may pick up odor quickly during storage therefore should not be
stored in the same room with other commodities.
34. Effect of cold storage on quality
• An unrefrigerated fruit or vegetable usually spoils rapidly and soon has
little food value for man. If similar fruits and vegetables are held
temporarily in cool storage, life processes are retarded, but the net result is
a longer period in which the food is acceptable for man to eat.
• It is not to be expected that a fruit after seven months storage will be
identical to a freshly harvested fruit. Occasionally it is necessary to
refrigerate fruits and vegetables in common storage chambers.
35. Storage of grains
• Grain stores better and more cheaply than other major foods.
• Storage is not an end in itself.
• Storage usually repeated in transporting grain from producer to processor to
consumer.
• as a minimum, grain must be stored from one harvest to the next.
• Storage of grains occurs on farms.
• Grain stores better when it is sound, clean and especially when it is dry.
• High moisture increases storage hazards.
• Moisture can be determines accurately and grain can be dried without damage to
its quality.
• The milling, baking quality, malting quality of wheat and corn can be damaged
when the kernels become too hot during drying.
36. • Technological changes are occurring steadily in the grain industry.
• Examples from the milling and baking industries are found in α amylase
activity and protein content.
• The importance of controlling α amylase is seen when mechanical work
during mixing dough is used to reduce the fermentation period in this
system.
• Bread of acceptable quality can be made from flour of lower protein content.
• When the protein content is reduced the moisture content of the bread is
more difficult to control.
• This difficulty can be offset by mechanically damaging the starch granules
during milling so that the starch will additional moisture.
• Damaged starch is more susceptible to attack by α amylase with consequent
deterioration of the crumb texture of the loaf.
37. • The α amylase in grain increases rapidly if the grain becomes wet after harvest and
starts to sprout.
• It can increase before visual evidence of sprouting is apparent.
• The first step in germination is the development and activation of enzymes.
• Their function is to transform the contents of the kernel, making them available to
nourish the new plant until the emerging roots and shoots take over the task.
• Control of α amylase can be exercised by visual examination for signs of incipient
sprouting or even weathering.
• Protein content of flour can be controlled by blending wheat's of appropriate protein
contents.
• The primary aim during storage is simply to prevent deterioration in quality. This is
done by indirectly through control of moisture, air movements and by preventing attack
my microorganisms, insects and pests.
38. Bulk storage
• Sinha (1973) describes a grain bulk or storage unit as a man made ecological
system in which living organisms and their non living environment interact.
• Deterioration results from interactions among physical, chemical and biological
variables.
• The environment of the grain physical variables such as temperature, Carbon
dioxide, oxygen , moisture and an array of organic compounds which are the by-
products of biological activity in the bulk.
39.
40. Temperature
• Atmospheric temperature and intergranular air temperature – safe
and prolonged storage
• Mites do not develop below 5°C, nor insects below 15 °C
• Fungi do not develop below 0°C
• Effect of temperature on an organism is correlated with the amount
of moisture present
Moisture
• Moisture content of below 13% arrest the growth of microorganism
• Maintaining Moisture content below 10% limit –storing grains
• Moisture content- changeable from season to season and from
climatic zone to another.
41. Respiration
• Both grain and microbial associates- respire by same physiological
principle
• Metabolism to produce energy- occurs either in presence or absence
of oxygen
• Effects – loss of weight, gain in moisture content, rise in the level of
co2 and rise in temperature of air.
Control of insects and mites
• Protection of grains- chemical treatments
• Use of fumigants, pesticides- prolonged protection against invasion by
pests
• Methyl bromide, ethylene oxide, hydrogen cyanide, ethylene
dibromide.