The document discusses the theoretical approach to autoclave validation. It begins by introducing key concepts like D-value, Z-value, and thermal death time (F-value) which are used to describe the resistance of microorganisms to sterilization processes. The mechanism of microbial death during sterilization, which typically follows first-order kinetics, is also explained. The relationships between D-value, temperature, and Z-value are defined mathematically. Determination of D-values, Z-values, and F-values allow validation of sterilization processes and calculation of sterilization probabilities.
1) The document discusses various thermal death rate concepts for bacterial spores during heat processing including D-value, Z-value, F-value, and the 12-D concept.
2) The D-value is the time required to reduce the bacterial population by 90% at a specific temperature, while the Z-value is the temperature change needed for a ten-fold change in D-value.
3) The F-value is a measure of sterilization calculated as the product of the decimal reduction time and the number of decimal reductions needed according to the 12-D concept, which requires a 12 log cycle reduction of Clostridium botulinum spores.
Freeze drying, also called lyophilization, is a process where material is frozen and then subjected to high vacuum pressure to sublime the frozen water in the form of vapor. It involves pretreating the product, freezing it, primary drying where ice sublimes under low pressure and heat, and secondary drying to remove remaining unfrozen water. Freeze drying retains most of the food's structure, flavor, and nutrients and produces a lightweight product with a long shelf life.
Freeze drying is a process that removes water from foods or other materials by freezing the product and then reducing pressure to allow the frozen water to sublimate from the solid to gas phase. It involves freezing, primary drying where the frozen water sublimates, and secondary drying to remove remaining unfrozen water. Freeze drying is useful for preserving foods, pharmaceuticals, and other temperature-sensitive materials as it avoids damaging heat and allows rehydration to the original state.
Thermal Death Time# TDT# Thermal Processing# Food Pocessing Technology# Thermal Death Time Concept # TDT Curve # Unit operations in Food Processing # Food Technology in Industry# Food
The document describes the working of a spray dryer. A spray dryer uses atomization to form fine liquid droplets that are then dried into powder particles by hot gas. The liquid is sprayed into a drying chamber and the droplets move in a helical path as hot air evaporates the moisture, forming dry particles within seconds. The dried particles are then recovered at the bottom while the hot air exits through the top. Spray drying allows rapid, continuous drying of heat-sensitive materials and produces free-flowing particles of uniform size.
Lyophilization, also known as freeze drying, is a process used to preserve thermolabile materials such as pharmaceuticals and food by removing water from the materials after they are frozen. The process involves freezing the material, reducing pressure to allow the frozen water to sublimate directly from the solid phase to gas phase, and then using low temperatures and pressure to remove remaining water. Freeze drying allows heat-sensitive materials to be dried without significant damage and results in a material that can be stored without refrigeration and reconstituted by adding water. Common applications of lyophilization include preserving vaccines, plasma, bacteria, and thermolabile pharmaceuticals to extend their shelf life.
1) The document discusses various thermal death rate concepts for bacterial spores during heat processing including D-value, Z-value, F-value, and the 12-D concept.
2) The D-value is the time required to reduce the bacterial population by 90% at a specific temperature, while the Z-value is the temperature change needed for a ten-fold change in D-value.
3) The F-value is a measure of sterilization calculated as the product of the decimal reduction time and the number of decimal reductions needed according to the 12-D concept, which requires a 12 log cycle reduction of Clostridium botulinum spores.
Freeze drying, also called lyophilization, is a process where material is frozen and then subjected to high vacuum pressure to sublime the frozen water in the form of vapor. It involves pretreating the product, freezing it, primary drying where ice sublimes under low pressure and heat, and secondary drying to remove remaining unfrozen water. Freeze drying retains most of the food's structure, flavor, and nutrients and produces a lightweight product with a long shelf life.
Freeze drying is a process that removes water from foods or other materials by freezing the product and then reducing pressure to allow the frozen water to sublimate from the solid to gas phase. It involves freezing, primary drying where the frozen water sublimates, and secondary drying to remove remaining unfrozen water. Freeze drying is useful for preserving foods, pharmaceuticals, and other temperature-sensitive materials as it avoids damaging heat and allows rehydration to the original state.
Thermal Death Time# TDT# Thermal Processing# Food Pocessing Technology# Thermal Death Time Concept # TDT Curve # Unit operations in Food Processing # Food Technology in Industry# Food
The document describes the working of a spray dryer. A spray dryer uses atomization to form fine liquid droplets that are then dried into powder particles by hot gas. The liquid is sprayed into a drying chamber and the droplets move in a helical path as hot air evaporates the moisture, forming dry particles within seconds. The dried particles are then recovered at the bottom while the hot air exits through the top. Spray drying allows rapid, continuous drying of heat-sensitive materials and produces free-flowing particles of uniform size.
Lyophilization, also known as freeze drying, is a process used to preserve thermolabile materials such as pharmaceuticals and food by removing water from the materials after they are frozen. The process involves freezing the material, reducing pressure to allow the frozen water to sublimate directly from the solid phase to gas phase, and then using low temperatures and pressure to remove remaining water. Freeze drying allows heat-sensitive materials to be dried without significant damage and results in a material that can be stored without refrigeration and reconstituted by adding water. Common applications of lyophilization include preserving vaccines, plasma, bacteria, and thermolabile pharmaceuticals to extend their shelf life.
Vacuum dryers work by reducing the chamber pressure below the vapor pressure of water through the application of vacuum, causing water to boil off rapidly without needing high heat. Vacuum dryers consist of an iron jacketed vessel containing hollow shelves and metal trays, connected to an oven and vacuum pump. Materials are dried in the trays under reduced pressure, allowing for rapid drying of heat-sensitive or hygroscopic substances through conduction without risk of degradation from high temperatures.
This document discusses biopreservatives, which are biologically derived antimicrobial substances used to preserve foods and extend shelf life. It notes that biopreservatives can reduce the need for chemical preservatives and intense heat treatments that negatively impact food quality. Various types of biopreservatives are described, including microbial acids like lactic acid and acetic acid, lacto-biopreservatives from milk, bacto-biopreservatives like bacteriocins, and phyto-antimicrobials from plants. Specific biopreservatives discussed in detail include lactic acid, acetic acid, citric acid, lactoferrin, nisin, and pedioc
A drum dryer consists of a horizontally mounted hollow steel drum that rotates at 1-10 rpm with steam passed through it. Liquid material from a feed pan adheres to the heated drum and is dried in a single rotation, with the dried material scraped off by a doctor's knife into a storage bin. Drum dryers are used to dry solutions, slurries, and suspensions quickly within 6-15 seconds, making them suitable for heat-sensitive materials, though they require more maintenance than spray dryers.
This document discusses membrane bioreactor processes and microfiltration. It provides details on microfiltration including that it uses membranes with pore sizes from 0.05-10 microns to separate particles like suspended solids and microorganisms. Microfiltration can be operated in dead-end or cross-flow configurations and is commonly used to treat wastewater and clarify beverages, pharmaceuticals, fruit juices, and water.
The document discusses unit operations in food processing. It defines a unit operation as a processing step where raw materials enter and a desired product exits. Important unit operations include heat transfer, drying, evaporation, separation processes, size reduction, mixing and shaping. Examples of specific unit operations used to produce many foods are provided, such as pasteurization, freezing, spray drying, centrifuging, grinding, blending and extrusion. The document focuses on freezing operations like plate, immersion, blast and fluidized bed freezing.
The document provides information on spray drying processes. It discusses that spray drying is a method to produce dry powders from liquids or slurries by rapidly drying with hot gas. Key aspects of spray drying include atomizing the feed into droplets, contacting the droplets with drying gas, evaporation of moisture from the droplets, and separating the dried powder. Different types of spray dryers and factors like flow patterns, atomization methods, and applications are described.
Canning is the process of sealing foods in containers and sterilizing them through heat to allow for long storage. It was invented in France in 1804 by Appert and involves selecting high quality fresh fruits and vegetables, washing, cutting, blanching, filling containers, exhausting air, sealing, heat processing, cooling, and storing in a cool, dry place. The multi-step process preserves foods by killing microorganisms and preventing recontamination.
Aseptic packaging involves sterilizing products and packaging materials under sterile conditions to prevent contamination and extend shelf life without refrigeration. It allows foods to be stored at ambient temperatures for months. The key aspects are pre-sterilizing the product using techniques like UHT and sterilizing packaging materials using methods like heat, chemicals, or radiation. Filled packages are then sealed quickly to maintain sterility. Common packaging types for aseptic storage include cartons, bags, bottles and cans. Aseptic packaging provides benefits like convenience, food safety, long shelf life and nutrient retention compared to canning.
introduction, theory of drying, applications of drying, construction & working about fluidised bed dryer,use of tray dryer,construction about vacuum dryer, construction & working about drum dryer, construction about spray dryer
Fermentation is a metabolic process that converts sugar into acids, gases, or alcohol through yeast or bacteria without oxygen. There are several types of industrial fermentations including batch, continuous, aerobic, and anaerobic. Batch fermentation involves filling a fermenter with raw materials, sterilizing it, inoculating with a pure culture, and processing the output before repeating. Continuous fermentation maintains microorganisms in logarithmic growth by continuously adding substrate. Aerobic fermentation uses oxygen while anaerobic fermentation does not. Yeast is commonly used in fermentation and is produced through steps of material preparation, culture preparation, fermentation, harvesting, filtration, and packaging using sugars as the basic energy source.
Shelf life determination involves identifying factors that cause food to spoil and monitoring attributes like sensory evaluation, microbiology, and chemistry over time under stored conditions. Direct methods involve storing samples and testing them periodically until endpoints are reached, while indirect methods use accelerated studies or predictive modeling to estimate shelf life. Determining shelf life is important for existing and new food products to ensure safety and quality over stated durations.
Fermented sausages are meat products made from comminuted meat and fat mixed with salt, curing agents, sugar and spices. They are produced through fermentation and are classified based on moisture content and pH. Semidry fermented sausages have a pH between 4.7-5.4 and moisture over 35%, while dry fermented sausages have a pH between 5.2-5.8 and moisture under 30%. Production involves mixing ingredients, filling casings, fermenting with starter cultures like Lactobacillus sakei, and sometimes smoking. Intrinsic factors like pH, meat type and fat content as well as extrinsic factors like temperature affect microbial growth during fermentation.
Drying is an essential process that involves transferring heat to remove moisture from wet products. Common drying methods include vacuum tray drying, freeze drying, rotary drum drying, spray drying, and pneumatic conveyor drying. Vacuum tray drying works by removing moisture through a vacuum, while spray drying uses nozzles to spray liquid droplets into a heated gas stream to evaporate water. Freeze drying preserves biological activity by freezing and then applying a vacuum to directly sublimate ice. Rotary drum dryers use a heated, rotating cylinder to dry materials, and pneumatic conveyor dryers suspend particles in a heated air stream to dry reasonably solid feeds.
This document discusses citric acid production through fermentation. It begins by introducing citric acid and describing its isolation from lemon juice. It is most commonly produced using the fungus Aspergillus niger through submerged fermentation. Several microorganisms can be used including bacteria, fungi and yeasts. Aspergillus niger is commonly used as it is easy to handle and can ferment a variety of raw materials like molasses to produce high citric acid yields. Citric acid can be produced through surface, submerged, and solid-state fermentation methods. Submerged fermentation is widely used as it allows for easier control and product recovery from the liquid fermentation broth. Citric acid has various applications in
This document discusses industrial sterilization processes on a large scale. It defines sterilization as destroying all forms of life. Sterilization is important for pharmaceutical products to eliminate contamination. Common sterilization processes include physical methods like heat and radiation, and chemical methods using gases or antimicrobial agents. Proper process selection and validation are important to ensure sterilized products meet specifications.
Tray dryers are used to dry wet solid materials like pharmaceuticals and chemicals. They consist of rectangular chambers containing racks that hold shallow trays loaded with the wet material. Heated air is circulated between the trays by fans and vents out moist air while pulling in fresh air. The trays are loaded with wet material and the heated air picks up water as it passes through in a single pass. Once dried, the trays or racks are removed and the dried material unloaded. Tray dryers are useful for small batch production of valuable materials but require more labor and have longer drying cycles than other dryers.
Freeze drying is a process that removes water from foods and other products after they are frozen and placed under a vacuum. This allows the ice in the product to change directly from a solid to vapor without passing through the liquid phase. Freeze drying preserves the integrity of the product's biological and chemical structure. The freeze drying process consists of three phases - freezing, primary drying, and secondary drying. During freezing, the product is frozen to separate the water. In primary drying, heat is applied under vacuum to sublime the ice directly into vapor. Secondary drying further removes water until the desired moisture level is reached. Freeze drying has advantages like long shelf life and retaining of color, taste and shape, though it is more expensive and time consuming than other
Freeze dryers work by first freezing the material and then using sublimation to turn frozen water directly into a gas. The key parts are drying chambers, heating coils, a vapor condensing system, and a vacuum pump. Freeze drying preserves the quality, shape, and rehydration properties of materials like foods and biological samples since it occurs below the freezing point and does not require melting. Its applications include heat-sensitive materials like foods, pharmaceuticals, and biological cultures.
Sterilization: F0 - what it means - how to calculate it - how to use itFedegari Group
F0: A technical note
- What it means
- How to calculate it
- How to use it for adjustment, control and
validation of moist-heat sterilization processes
This document provides an overview of sterilization principles and methods. It defines key terms like sterility, sterilization, and aseptic processing. It describes various sterilization methods including moist heat, dry heat, chemicals, and radiation. It outlines sterilization criteria used to evaluate effectiveness, including death/survival rates, D values, inactivation factors, death rate constants, Z values, Q values, and F values. Finally, it discusses sterilization validation and monitoring, covering the use of biological and chemical indicators.
Vacuum dryers work by reducing the chamber pressure below the vapor pressure of water through the application of vacuum, causing water to boil off rapidly without needing high heat. Vacuum dryers consist of an iron jacketed vessel containing hollow shelves and metal trays, connected to an oven and vacuum pump. Materials are dried in the trays under reduced pressure, allowing for rapid drying of heat-sensitive or hygroscopic substances through conduction without risk of degradation from high temperatures.
This document discusses biopreservatives, which are biologically derived antimicrobial substances used to preserve foods and extend shelf life. It notes that biopreservatives can reduce the need for chemical preservatives and intense heat treatments that negatively impact food quality. Various types of biopreservatives are described, including microbial acids like lactic acid and acetic acid, lacto-biopreservatives from milk, bacto-biopreservatives like bacteriocins, and phyto-antimicrobials from plants. Specific biopreservatives discussed in detail include lactic acid, acetic acid, citric acid, lactoferrin, nisin, and pedioc
A drum dryer consists of a horizontally mounted hollow steel drum that rotates at 1-10 rpm with steam passed through it. Liquid material from a feed pan adheres to the heated drum and is dried in a single rotation, with the dried material scraped off by a doctor's knife into a storage bin. Drum dryers are used to dry solutions, slurries, and suspensions quickly within 6-15 seconds, making them suitable for heat-sensitive materials, though they require more maintenance than spray dryers.
This document discusses membrane bioreactor processes and microfiltration. It provides details on microfiltration including that it uses membranes with pore sizes from 0.05-10 microns to separate particles like suspended solids and microorganisms. Microfiltration can be operated in dead-end or cross-flow configurations and is commonly used to treat wastewater and clarify beverages, pharmaceuticals, fruit juices, and water.
The document discusses unit operations in food processing. It defines a unit operation as a processing step where raw materials enter and a desired product exits. Important unit operations include heat transfer, drying, evaporation, separation processes, size reduction, mixing and shaping. Examples of specific unit operations used to produce many foods are provided, such as pasteurization, freezing, spray drying, centrifuging, grinding, blending and extrusion. The document focuses on freezing operations like plate, immersion, blast and fluidized bed freezing.
The document provides information on spray drying processes. It discusses that spray drying is a method to produce dry powders from liquids or slurries by rapidly drying with hot gas. Key aspects of spray drying include atomizing the feed into droplets, contacting the droplets with drying gas, evaporation of moisture from the droplets, and separating the dried powder. Different types of spray dryers and factors like flow patterns, atomization methods, and applications are described.
Canning is the process of sealing foods in containers and sterilizing them through heat to allow for long storage. It was invented in France in 1804 by Appert and involves selecting high quality fresh fruits and vegetables, washing, cutting, blanching, filling containers, exhausting air, sealing, heat processing, cooling, and storing in a cool, dry place. The multi-step process preserves foods by killing microorganisms and preventing recontamination.
Aseptic packaging involves sterilizing products and packaging materials under sterile conditions to prevent contamination and extend shelf life without refrigeration. It allows foods to be stored at ambient temperatures for months. The key aspects are pre-sterilizing the product using techniques like UHT and sterilizing packaging materials using methods like heat, chemicals, or radiation. Filled packages are then sealed quickly to maintain sterility. Common packaging types for aseptic storage include cartons, bags, bottles and cans. Aseptic packaging provides benefits like convenience, food safety, long shelf life and nutrient retention compared to canning.
introduction, theory of drying, applications of drying, construction & working about fluidised bed dryer,use of tray dryer,construction about vacuum dryer, construction & working about drum dryer, construction about spray dryer
Fermentation is a metabolic process that converts sugar into acids, gases, or alcohol through yeast or bacteria without oxygen. There are several types of industrial fermentations including batch, continuous, aerobic, and anaerobic. Batch fermentation involves filling a fermenter with raw materials, sterilizing it, inoculating with a pure culture, and processing the output before repeating. Continuous fermentation maintains microorganisms in logarithmic growth by continuously adding substrate. Aerobic fermentation uses oxygen while anaerobic fermentation does not. Yeast is commonly used in fermentation and is produced through steps of material preparation, culture preparation, fermentation, harvesting, filtration, and packaging using sugars as the basic energy source.
Shelf life determination involves identifying factors that cause food to spoil and monitoring attributes like sensory evaluation, microbiology, and chemistry over time under stored conditions. Direct methods involve storing samples and testing them periodically until endpoints are reached, while indirect methods use accelerated studies or predictive modeling to estimate shelf life. Determining shelf life is important for existing and new food products to ensure safety and quality over stated durations.
Fermented sausages are meat products made from comminuted meat and fat mixed with salt, curing agents, sugar and spices. They are produced through fermentation and are classified based on moisture content and pH. Semidry fermented sausages have a pH between 4.7-5.4 and moisture over 35%, while dry fermented sausages have a pH between 5.2-5.8 and moisture under 30%. Production involves mixing ingredients, filling casings, fermenting with starter cultures like Lactobacillus sakei, and sometimes smoking. Intrinsic factors like pH, meat type and fat content as well as extrinsic factors like temperature affect microbial growth during fermentation.
Drying is an essential process that involves transferring heat to remove moisture from wet products. Common drying methods include vacuum tray drying, freeze drying, rotary drum drying, spray drying, and pneumatic conveyor drying. Vacuum tray drying works by removing moisture through a vacuum, while spray drying uses nozzles to spray liquid droplets into a heated gas stream to evaporate water. Freeze drying preserves biological activity by freezing and then applying a vacuum to directly sublimate ice. Rotary drum dryers use a heated, rotating cylinder to dry materials, and pneumatic conveyor dryers suspend particles in a heated air stream to dry reasonably solid feeds.
This document discusses citric acid production through fermentation. It begins by introducing citric acid and describing its isolation from lemon juice. It is most commonly produced using the fungus Aspergillus niger through submerged fermentation. Several microorganisms can be used including bacteria, fungi and yeasts. Aspergillus niger is commonly used as it is easy to handle and can ferment a variety of raw materials like molasses to produce high citric acid yields. Citric acid can be produced through surface, submerged, and solid-state fermentation methods. Submerged fermentation is widely used as it allows for easier control and product recovery from the liquid fermentation broth. Citric acid has various applications in
This document discusses industrial sterilization processes on a large scale. It defines sterilization as destroying all forms of life. Sterilization is important for pharmaceutical products to eliminate contamination. Common sterilization processes include physical methods like heat and radiation, and chemical methods using gases or antimicrobial agents. Proper process selection and validation are important to ensure sterilized products meet specifications.
Tray dryers are used to dry wet solid materials like pharmaceuticals and chemicals. They consist of rectangular chambers containing racks that hold shallow trays loaded with the wet material. Heated air is circulated between the trays by fans and vents out moist air while pulling in fresh air. The trays are loaded with wet material and the heated air picks up water as it passes through in a single pass. Once dried, the trays or racks are removed and the dried material unloaded. Tray dryers are useful for small batch production of valuable materials but require more labor and have longer drying cycles than other dryers.
Freeze drying is a process that removes water from foods and other products after they are frozen and placed under a vacuum. This allows the ice in the product to change directly from a solid to vapor without passing through the liquid phase. Freeze drying preserves the integrity of the product's biological and chemical structure. The freeze drying process consists of three phases - freezing, primary drying, and secondary drying. During freezing, the product is frozen to separate the water. In primary drying, heat is applied under vacuum to sublime the ice directly into vapor. Secondary drying further removes water until the desired moisture level is reached. Freeze drying has advantages like long shelf life and retaining of color, taste and shape, though it is more expensive and time consuming than other
Freeze dryers work by first freezing the material and then using sublimation to turn frozen water directly into a gas. The key parts are drying chambers, heating coils, a vapor condensing system, and a vacuum pump. Freeze drying preserves the quality, shape, and rehydration properties of materials like foods and biological samples since it occurs below the freezing point and does not require melting. Its applications include heat-sensitive materials like foods, pharmaceuticals, and biological cultures.
Sterilization: F0 - what it means - how to calculate it - how to use itFedegari Group
F0: A technical note
- What it means
- How to calculate it
- How to use it for adjustment, control and
validation of moist-heat sterilization processes
This document provides an overview of sterilization principles and methods. It defines key terms like sterility, sterilization, and aseptic processing. It describes various sterilization methods including moist heat, dry heat, chemicals, and radiation. It outlines sterilization criteria used to evaluate effectiveness, including death/survival rates, D values, inactivation factors, death rate constants, Z values, Q values, and F values. Finally, it discusses sterilization validation and monitoring, covering the use of biological and chemical indicators.
1. Dry heat sterilization involves exposing items to high temperatures without moisture present to destroy microorganisms. Temperatures above 140°C for multiple hours are required.
2. The effectiveness of dry heat sterilization depends on factors like the degree of heat used, exposure period, and moisture level. Higher temperatures and longer exposure times are needed compared to moist heat sterilization.
3. Dry heat is best for heat-resistant, non-melting items like glassware, metalware, and oils. Paper, rubber, and plastics may degrade or melt at the high temperatures required. Proper packaging is also needed to prevent recontamination after sterilization.
Thermal Death Kinetics and various IsothermsSasiK25
This document discusses the kinetics of thermal death of microorganisms during sterilization. It explains that steam sterilization is commonly used except for animal cell culture media which is sterilized using filtration. The destruction of microorganisms by heat sterilization can be modeled as a first-order chemical reaction. The thermal death kinetics follow an exponential decay model where the log of surviving microorganisms decreases linearly over time. The specific death rate constant increases with temperature and can be determined experimentally.
1) The document discusses various thermal death rate concepts for bacterial spores during heat processing including D-value, Z-value, F-value, and the 12-D concept.
2) The D-value is the time required to reduce the bacterial population by 90% at a specific temperature, while the Z-value is the temperature change needed for a ten-fold change in D-value.
3) The F-value is a measure of sterilization calculated as the product of the decimal reduction time and the number of decimal reductions needed according to the 12-D concept which aims for a 12 log cycle reduction of Clostridium botulinum spores.
Application of MicroTester for detection of low microbial contaminationOlivér Reichart
Advantades of the redox method in the evaluation of membrane filtration:
* The time requirement of the redox-potential technique is significantly lower than that of the classical nutrient methods.
* While the classical methods use only 1 membrane in 1 Petri dish the redox-potential method makes possible to evaluate even 5 or more filters in one test cell. That means not only a 5 times lower detection limit of microbes but results in a remarkable cost reduction as well.
Bahan Ajar 2 - PengBio Rivaldi Sidabutar.pptxRivaldiDiCaprio
This document provides an introduction to bioprocessing and control of microbial growth. It defines key terms related to sterilization and microbial control. Methods of microbial control discussed include heat sterilization using autoclaves, filtration, and chemical disinfectants. The kinetics of microbial growth are described using equations for exponential growth, substrate utilization, and calculating yields. Different modes of fermentation processes like batch, continuous, and fed-batch are introduced. The next meeting will cover cell disruption, kinetics of continuous culture, yield calculations, and applications of batch and continuous processes.
Food Processing and preservation 3 - Sterilization.pdfPeterJofilisi
The document discusses food sterilization and preservation through heat processing. It describes sterilization as using high heat to destroy microbes and enzymes, giving foods a shelf life over 6 months. The factors that influence sterilization time include heat resistance of microbes, heating conditions, food acidity, and container size. Proper sterilization requires knowledge of microbe concentrations and heat resistance. Microbe death through heat follows a logarithmic order and can be measured using D-values and Z-values. Different container types and the rate of heat penetration must also be considered for effective sterilization.
Food Processing and preservation 3 - Sterilization.pdfPeterJofilisi
The document discusses food sterilization and preservation through heat processing. It describes sterilization as using high heat to destroy microbes and enzymes, giving foods a shelf life over 6 months. The factors that influence sterilization time include heat resistance of microbes, heating conditions, food acidity, and container size. Proper sterilization requires knowledge of microbe concentrations and heat resistance. Microbe death through heat follows a logarithmic order and can be measured using D-values and Z-values. Different container types and the rate of heat penetration must also be considered for effective sterilization.
A biological indicator is a standardized preparation of viable microorganisms, usually bacterial spores, that is carried either directly by some of the items to be sterilized or by carriers such as filter papers, porcelain cylinders, that serve as a challenge to the effectiveness of a given sterilization cycle
The document discusses various methods for controlling microorganisms, including physical methods like heat, filtration, and radiation, as well as chemical agents. It provides definitions for key terms like sterilization, disinfection, and sanitization. For physical heat methods, it describes moist heat sterilization techniques like boiling, autoclaving, pasteurization, and ultrahigh-temperature processing. It also covers factors that influence the effectiveness of antimicrobial agents and calculations using D-values and z-values to determine sterilization times.
This study assessed the antimicrobial activity and longevity of N-halamine (1-chloro-2,2,5,5-tetramethyl-4-imidazoidinone or MC), a non-bleaching compound, coated on various materials in broiler chicken houses. Results showed that MC solutions with a concentration of 0.04% or higher could kill Salmonella Typhimurium and Campylobacter jejuni within 30 minutes. Materials coated with 1% MC maintained effectiveness against both pathogens for at least 4 weeks, with active chlorine decreasing from an initial 1016 atoms/cm2 to 1015 atoms/cm2 over 3 weeks. Therefore, MC shows potential as a novel antim
Redox-potential measurement as a rapid method for microbiological testingOlivér Reichart
Introduction to the application of redox-potential measurement in microbiological testing, including MPN. Calibration and validation characteristics are shown. Advantages of this method:
* Very simple measurement technique.
* It does not require strict temperature control.
* Rapid method, especially in the case of high contamination.
* Applicable for every nutrient broth (impedimetric methods require special substrates with low conductance).
* Especially suitable for the evaluation of the membrane filter methods.
* Economic, effective and simple method for heat destruction measurements.
* Effective tool for the optimization of the nutrient media.
* The test costs are less than those of the classical methods, especially in the case of zero tolerance in quality control (coliforms, Enterococcus, Pseudomonas, etc.).
The document describes an experiment examining the effect of different culturing conditions on the growth of Methicillin-resistant Staphylococcus aureus (MRSA) strains. Five MRSA strains were cultured under various time, temperature, and tryptone concentration levels. ANOVA and polynomial regression analyses found that time, temperature, and concentration all significantly affected bacterial counts, with some interaction effects. The optimal conditions estimated were 48 hours for time and 35°C for temperature based on maximizing counts in the regression models.
This document summarizes accelerated stability studies which are designed to increase the rate of chemical degradation and physical change of a drug by using exaggerated storage conditions as part of formal stability testing. The main objectives are to predict a drug product's stability profile and shelf life before market launch and to rapidly detect deterioration between initial formulations. Common factors affecting drug shelf life and changes observed under accelerated conditions are described. Methods for determining shelf life from accelerated stability data, including the Arrhenius plot and t90 values, are outlined. Limitations of the approach are noted. Kinetic models including zero order, first order, and pseudo-first order reactions are also defined.
Sterilization refers to any process that removes, kills, or deactivates all forms of life (in particular referring to microorganisms such as fungi, bacteria, viruses, spores, unicellular eukaryotic organisms such as Plasmodium, etc.
In DSC the heat flow is measured and plotted against temperature of furnace or time to get a thermo gram. This is the basis of Differential Scanning Calorimetry (DSC).
The deviation observed above the base (zero) line is called exothermic transition and below is called endothermic transition.
The rate of a reaction is the amount of chemical change occurring per unit time. It can be expressed as the decrease in concentration of a reactant or increase in concentration of a product over time. The rate is influenced by temperature, concentration of reactants, nature of reactants, presence of catalysts, and radiation. Reactions can be zero order, first order, or second order depending on how the rate depends on the concentration of reactants. The order and molecularity of a reaction are different concepts. Chain reactions involve initiation, propagation, and termination steps that regenerate reactive intermediates to sustain the reaction.
This document summarizes a study on the thermal kinetics of thin layer drying of Indian gooseberry (aonla) flakes. Experiments were conducted to dry aonla flakes at air velocities of 0.48m/s, temperatures ranging from 40-75°C, and relative humidity of 35%. Moisture content was measured periodically to calculate moisture ratio. Drying coefficients were determined using the half life time method and linear regression analysis. The experimental data was best fitted by the Modified Page model with reasonably low root mean square errors between 0.0094-0.0382 and high efficiencies between 0.9598-0.9985. Correlations for the drying coefficient and shape factor in terms of temperature were also
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
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These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
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3. Table of contents
1. Objectives
2. Introduction
3. Mechanism of microbial death
3.1. D-value (decimal reduction time)
3.2. Z-value (thermal resistance constant)
3.3. Thermal death time (TDT), (F value)
3.4. Lethal Rate
3.5. Mathematical F0 value
3.6. Probability of Non sterile unit (PNSU)
3.7. Determination of minimum required Fo
4. Biological indicators (BI)
3
4. 1. Objectives
After this training trainees are able to understand:
Mechanism of microbial death.
The concepts of D,Z and F values and their relationship.
How D-value, Z-value and F-value be determined.
The difference between clock time and thermal death time/F
value.
How minimum Fo value and lethal rate can be determined.
4
5. 2.Introduction
Sterile pharmaceutical products should be:
Free from microorganisms
Free from pyrogens/endotoxin
Free from particulates, and chemicals
The ultimate goal is absolute absence of microbial contamination
(since sterility specification is an absolute value)
But sterility can not be assured by end product testing (sterility
testing).
5
6. Limitation of Sterility Test
It is destructive test.
Depends on sample size.
Low concentration of microbial contamination may not be
detected.
False positive result (contamination of culture media by
personnel).
•With the sterility test method to ensure absolute sterility, all
samples would have to be tested.
•And hence validation is important to minimize the reliance on
end-product testing.
•An alternative approach to predicting sterilization is the
definition of sterility as a probability of survival. This
probability is related to knowledge of the mechanism of
microbial death and the condition causing it.
6
7. Based on this approach Sterilization can be defined as a process
used to render a product free of viable organisms with specified
probability.
The most prevalent description of sterility used today is the
reduction of anticipated levels of contamination in a load to the
point at which the probability of survival is less than
1/1,000,000 (1 in 1 million).
Once the levels of microbial contamination and resistance to the
sterilization process are known, probability of survival can be
calculated.
7
8. Significant research data support the theory that microbial death
may be described as a first order chemical reaction. This leads to
the conclusion that death is essentially a single molecule
reaction.
First order reaction: is a chemical reaction in which the rate
depends on the concentration of one reactant. The rate of
reaction is governed by the concentration of the reactant (spore).
It is a chemical reaction in which the reaction rate is
proportional at all times only to the amount of reactant still to be
degraded.
3. Mechanism of microbial death
8
9. From chemical kinetics, if the disappearance of a
species/spores, A follows first order kinetics, then the rate
equation is expressed as;
d[A]/dt=-k[A].........Rate of concentration decrease of spores.
Where; A-reactant(spore/bacteria), B-product/dead spore, k-
rate constant
Mechanism...
9
10. If we use N for number of microbial survivors in a suspension
subjected to heating,
DN/dt=-KN
DN/N=-dKt
After integrating the equation we can get,
lnN/N0=kt where, N- final microbial concentration, N0- initial
microbial concentration, k-rate constant and t-time.
If we plot the number of spore survivors against time, we can
obtain exponentially decreasing graph as shown below.
Mechanism ...
10
Survivor curve
11. The concept of first order chemical reaction seems obvious for dry
heat sterilization, but not for moist heat sterilization, in which steam
or superheated water would appear to take part in the reaction. A
actually, this bimolecular reaction is a first-order reaction, because an
excess of steam or superheated water is always present and its
concentration can be considered constant.
Regardless of the type of lethality induced by a sterilization process
whether it be heat, chemical or radiation microorganisms upon
exposure to adequate level of such treatment, will die according to a
logarithmic relationship between the concentration or population of
spores and the time exposure or radiation dose to the treatment.
Mechanism ...
11
12. If a homogeneous suspension of microorganisms is heated at constant
temperature, the microorganism destruction commonly follows
logarithmic order of death.
Mechanism ...
12
logarithmic /exponential function with negative slope (eg)
13. It is possible to use semi logarithm plot.
Semi logarithm plot: having one scale logarithm and other arithmetic
plot.
By converting number of spores to logarithmic value and plotting it
against exposure time we can get straight line graph.
Mechanism ...
13
14. Heat sterilization is a function of probability that is dependent on;
i. The number of challenge microorganisms.
ii. The heat resistance of these microorganisms.
iii. The amount of heat exposure.
When microbes/spores are subjected to heating or radiation , they
will show some resistance to the sterilant. Such resistance can be
expressed as D-value (decimal reduction time).
14
Mechanism ...
15. 3.1. D-value (decimal reduction time)
D-value is used to describe the relative resistance of particular
microorganism to a sterilization process.
It is heating time in minutes at constant temperature that will result in
reducing microorganisms by a factor of 10.
It is time in minutes required to inactivate 1 log of a challenge
microorganism.
15
Mechanism ...
16. It is the time in minutes required to reduce 1,000 spores to 100.
It is the time required for a 90% reduction in the microbial population.
i.e. No=1,000 spores, N= 100 spores, % change=(1000-
100)(100%)/1000 =90%
NB. -D-value remains the same for each log cycle.
-D-value does not depend upon the initial number of
microorganisms present.
- It is expressed in time unit (in minutes).
D-value...
16
17. 17
log N= -k(t)/2.303+ log No
Let No=1000 and N=100, then
Log 100=-kt/2.303+log 1000
Log 100/1000=-kt/2.303
Log 0.1=-kt/2.303
-1=-kt/2.303
t=2.303/k, but t=D
D=2.303/k
D-value...
18. 18
The D value is important in the validation of sterilization
processes for several reasons.
1. It is a specific kinetic expression for each micro-organism in a
specific environment subjected to a specific sterilization agent
or condition.
In other words, the D value will be affected by;
a. The type of microorganism used as the biological indicator.
b. The formulation components and characteristics (e.g., pH).
c. The surface on which the micro-organism is exposed (glass,
steel, plastic, rubber, in solution, dry powder, etc.).
D-value...
19. 19
d. The temperature, gas concentration, or radiation dose of the
particular sterilization process.
3. Knowledge of the D value at different temperatures in heat
sterilization is necessary for the calculation of the Z value.
4. The D value is used in the calculation of the biological F value.
D-value...
20. 20
How to determine D-value
There are different methods of D-value determination but it can
be easily determined by using Semilog paper and using spread
sheet.
The spreadsheet method uses the concept of simple regression
analysis.
Eg. Determine D-value of microorganism from the following
data at 120˚C. (ans=3.025 min).
TIME •
•
•
•
•
•
(minutes) NUMBER OF SURVIVORS
0 106
3 1.2X105
6 1.1X104
9 1.2X103
12 1.1X102
D-value...
21. 21
How to relate D values at different temperatures
D values at different temperatures can be related to each other.
For example the D value at temperature T can be related to
121.1˚C.
D-value...
22. 22
Eg. If the D value of a certain spore is 5 minutes at 121.1˚C,
what will be the D value of the spore at 111.1˚C (Z=10˚C).
Ans=50 min.
NB. D value increases when temperature decreases.
D-value...
23. 23
3.2. Z-value (thermal resistance constant)
Z-value describes the influence of temperature on decimal
reduction time, D for microbial population.
It is the increase in temperature necessary to cause a 90%
reduction in D value (1 log reduction).
Recall that D value is obtained at a constant temperature and if
we plot log D value against temperature on a semilog paper then
the temperature change for one log cycle reduction will give us
Z value.
Thermal resistance plots of log D versus temperature, showing slopes equivalent
to Z = 10°C and Z = 20°C
24. 24
Z-value…
The most commonly used value of z for the destruction of
microbial spores is 10˚C (18˚F). This is based on experimental
observations for Geobacillus stearothermophilus and Clostridium
botulinum, both highly heat resistant organisms. These
organisms are chosen for divergent reasons. C. botulinum was
the subject of the pioneering experiments by food scientists
attempting to destroy this deadly cause of botulism in canned
foods. G. stearothermophilus is a readily available and safe
indicator organism for use in sterilization studies and has similar
resistance.
25. 25
Z-value….
Eg. Determine Z value for spore suspension if the following D
values were obtained for different temperature. (ans=16.58˚C)
Temperature (°C) D value(minutes)
102 28.5
106 15.6
110 8
114 5.1
118 3.1
26. 26
3.3. Thermal death time (TDT), (F value)
The usefulness of the temperature dependent model in moist
heat sterilization autoclave is to calculate the lethality of the
cycle over a range of temperature (including heat up and cool
down). To do this a new variable ,closely related to D value is
introduced. This is called F, value (Thermal death time).
It can also called process lethality.
F value is defined as the number of minutes required to
destroy a given number of organisms at a given temperature.
But D value is the number of minutes required to destroy 90%
of organisms at a given temperature.
28. 28
Thermal death…
Reduce microbial population from 10,000
to 1,000, F=1D
Reduce microbial population from 10,000
to 100, F=2D
Reduce microbial population from 10,000
to 10, F=3D
So F is nothing but it is a multiple of D
value.
And hence we can say that F=nD, where n
is log reduction.
Both the thermal resistance curve (log D
vsT) and the thermal death time curve (log
F vs T) are dependent on z, have the same
curve.
30. 30
3.4. Lethal Rate
Lethal rate: is defined as the equivalent time for any specific
temperature relative to another temperature (usually 121.1˚C).
This reference temperature (121.1˚C) is chosen as a base
because it is an economical and effective one for moist heat
sterilization. But it should not be assumed that 121.1˚C is
required to achieve effective sterilization.
31. 31
Lethal Rate…
Example1: the lethal rate for 117.0˚C relative to 121.1˚C
(assuming a z value of 10) is 0.4. This means that for every full
minute (60 seconds) of process time at a temperature of 117˚C,
the process is “credited with” the equivalent of only 0.4 minute
at 121.1˚C.
Example 2: for a process that ran for 12minuets at exactly
119.1˚C, what will be the equivalent time with respect to 121.1
˚C? (7.56min)
32. 32
Lethal Rate…
10
(121.1-T )/z=FT/F121.1˚c ), where F121.1˚c /FT)=L and FT =1 minute
And then; 10
(T -121.1)/z=L, z =10˚c
The logic behind is that for every 1 minute exposure of a spore at
a certain temperature has given an equivalent exposure time
(“credit”) of less or greater that one minutes at 121.1ºC.
Temperatures below 100˚C generally add insignificant credit to
the overall sterilization assessment.(L = 0.008 min).
Heat penetration curve
33. 33
3.5. Mathematical F0 value
F value measures equivalent time, not clock time, that a monitored
article is exposed to the desired temperature.
F0 is a summation over time of the instantaneous lethal rates at a
series of temperatures. In integral form this is;
where ∆t is the chosen time interval and T is the average temperature
over that interval. The smaller the interval chosen, the more accurate
the calculation will be.
34. 34
Mathematical F0 …
An F-value is the number of minutes to kill a specified number of
microorganisms with a specified Z-value at a specific temperature.
An Fo value is the number of minutes to kill a specified number of
microorganisms with a Z-value of 10°C (50°F) at a temperature of
121.1°C (250°F).
When the assumption of z=10˚c is used F is written as Fo. This is
the most commonly used measure of the lethality of a sterilization
process spanning a range of temperatures.
It is a common practice to use the F0 equation to determine the
probability of sterility or SAL.
Eg. What is the F0 value for a process that ran for 12 minutes at
exactly 121.1˚C (ans. F0=12min).
36. 36
Mathematical F0 …
Another equation for the F value as depicted below given in the
following expression:
Where L= 10(T−T0)/Z which is the lethality constant integrated
over time limits between time 1 and time 2. Integrating the above
question between two time points will yield the area under the
10(T−T0)/Z versus time curve.
37. 37
Mathematical F0…
Plot showing the difference between chamber temperature versus time
(___ ) and lethal rate in the product versus time (----). F is the area under the dotted line curve
39. 3.6. Probability of Non sterile unit (PNSU)
It is also known as sterility assurance level (SAL)
From the above graph we can derive the following equation,
Log No/N=F/D
Where, No is initial population
N is final population
F is total destruction time
D decimal reduction time
39
40. SAL…
Note that in microbial challenge test, a certain number of
spores (usually 106) is inoculated in a single container, however
in actual scenario the microorganisms/spores might be
distributed and found in all container (eg bags).
Lets say r= number of bags sterilized, No=number of spores per
bag , rNo= total number of spores at the beginning and rN=
total number of spores at the end of sterilization process
respectively.
Substituting in the above equation;
Log rNo/rN=F/D
If we want only one bag at the end of heating to contain a
spore, then rN=1, the equation become Log rNo=F/D
40
41. SAL…
After rearranging we can get;
rNo=10F/D or 1/r= No and this is the equation of PNSU(SAL)
10F/D
Eg. No =104 and if we use 12D, 1/r= No = 104/ 1012 = 10-8
1012D/D
Therefore incidence of survival is 1 bag in 108 bags
41
42. 3.7. Determination of minimum required Fo
Quite often the process designer will need to know precisely how
much Fo to provide for in a new sterilization cycle to meet a
desired sterility assurance required, together with the bioburden
of the product being sterilized and the resistance of indigenous
microorganism in the bioburden using formula.
Fo= D121.1˚c (log No-log N)
Where, No-initial bioburden, N- maximum acceptable SAL.
Eg. The product being sterilized has a bioburden of 100 spores
per container, the D value of the spore is 3.3 minutes and the
desired SAL is no more than 1 unit in 1 million units will be non-
sterile.(ans ,26.4 min.).
42
43. 4. Biological indicators (BI)
A Biological Indicator: is a characterized preparation of specific
microorganisms resistant to a particular sterilization process. It is
used to assist in the qualification of the physical operation of
sterilization
There are three forms of BI’s:
SPORE STRIPS: Paper strips inoculated with spores and
placed inside a glassine envelope.
AMPOULE: glass vial filled with spore suspension and
chemical indicator.
SUSPENSION: solution of spores suspended in Ethanol or
Water used for direct surface inoculation.
43