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2 1 Safe And Un Safe Foods
- 1. By VINU FOOD PRODUCTS 15-11-2011 A Presentation by VINU FOOD PRODUCTS 1
- 2. 1. Safe and Un-Safe Foods 1.1 FEW SIMPLE QUESTIONS ????? Are you Feeling sick very often? Are your children look unhealthy & feeling tired very often What is the most common reason for getting sick? Why do you get dysentery problems very often 15-11-2011 A Presentation by VINU FOOD PRODUCTS 2
- 3. 1. Safe and Un-Safe Foods 1.2 THE ANSWER IS: Its Nothing…. But something you ate…… "you and your health are what you eat“ They are the results of un-safe food 15-11-2011 A Presentation by VINU FOOD PRODUCTS 3
- 4. 1. Safe and Un-Safe Foods 1.3 FOR GOOD HEALTH: Body Needs: CAN THE NEED BE MET BY: Carbohydrates Lot of tasty fried potatoes chips Lot of barotta from street side restaurant Proteins Lot of sundal from the beach side vendors Fat Lot of deep fried Chilly Gobi / chicken Sugar Lot of low cost sweets For Vitamins and Minerals Milk Lot of ice creams from street vendors Fruits Chemically ripened fruits Vegetables Grown with the use of lot of pesticides 15-11-2011 A Presentation by VINU FOOD PRODUCTS 4
- 5. 1. Safe and Un-Safe Foods 1.3 FOR GOOD HEALTH: Body Needs: CAN THE NEED BE MET BY: Carbohydrates Lot of tasty fried potatoes chips Lot of barotta from street side restaurant Proteins Lot of sundal from the beach side vendors Fat Lot of deep fried Chilly Gobi / chicken Sugar Lot of low cost sweets For Vitamins and Minerals Milk Lot of ice creams from street vendors Fruits Chemically ripened fruits Vegetables Grown with the use of lot of pesticides 15-11-2011 A Presentation by VINU FOOD PRODUCTS 5
- 6. 1. Safe and Un-Safe Foods 1.3 FOR GOOD HEALTH: Body Needs: CAN THE NEED BE MET BY: Carbohydrates Lot of tasty fried potatoes chips Lot of barotta from street side restaurant Proteins Lot of sundal from the beach side vendors Fat Lot of deep fried Chilly Gobi / chicken Sugar Lot of low cost sweets For Vitamins and Minerals Milk Lot of ice creams from street vendors Fruits Chemically ripened fruits Vegetables Grown with the use of lot of pesticides 15-11-2011 A Presentation by VINU FOOD PRODUCTS 6
- 7. 1. Safe and Un-Safe Foods 1.4 Food Classifications on Safety Aspect SAFE FOOD HEALTH HAZARD FOOD POISONOUS FOOD 15-11-2011 A Presentation by VINU FOOD PRODUCTS 7
- 8. 1. Safe and Un-Safe Foods 1.5 Transition from Safe to Un-safe food SAFE FOOD HEALTH HAZARD FOOD POISONOUS FOOD 15-11-2011 A Presentation by VINU FOOD PRODUCTS 8
- 9. 1. Safe and Un-Safe Foods 1.6 Health Effects of different classes of food Healthy if in-take is about the Balanced diet SAFE FOOD requirement Un-Healthy if in-take is more/less than the HEALTH Balanced diet HAZARD requirement FOOD Health Hazard if that food is restricted due to POISONOUS health problems FOOD 15-11-2011 A Presentation by VINU FOOD PRODUCTS 9
- 10. 1. Safe and Un-Safe Foods 1.6 Health Effects of different classes of food Health Hazard if in-take is more than recommended SAFE FOOD quantity of the ingredient that made the food health HEALTH hazard HAZARD Health Hazard if that FOOD ingredient is restricted due to health problems Delayed Effect: POISONOUS Affects the body over a FOOD period 15-11-2011 A Presentation by VINU FOOD PRODUCTS 10
- 11. 1. Safe and Un-Safe Foods 1.6 Health Effects of different classes of food SAFE FOOD HEALTH HAZARD FOOD Serious Health Hazard even in small quantity. Immediate effect: POISONOUS Will affect the body in FOOD 1-36 hrs. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 11
- 12. 1. Safe and Un-Safe Foods 1.7 An example of Un-safe Food: Constant Part of our Lunch – Pickle Major Constituents of Pickle: Lime/Mango/Ginger/Garlic – the main part of pickle - Rs. 25 – 50 Rs. per Kg Edible oil - 50 – 100 Rs. per Kg Pickle spices – chilies, coriander, turmeric, mustard etc. – 50 – 100 Rs. per Kg With the above prices, a good pickle will cost more than Rs. 50 / kg to prepare. BUT One can buy it at a price of Rs.30/kg (retail) with a Cost of production of less than Rs. 20/kg 15-11-2011 A Presentation by VINU FOOD PRODUCTS 12
- 13. 1. Safe and Un-Safe Foods 1.7 An example of Un-safe Food: Constant Part of our Lunch – Pickle Major Constituents of Pickle: Lime/Mango/Ginger/Garlic – the main part of pickle - Rs. 25 – 50 Rs. per Kg Edible oil - 50 – 100 Rs. per Kg Pickle spices – chilies, coriander, turmeric, mustard etc. – 50 – 100 Rs. per Kg With the above prices, a good pickle will cost more than Rs. 50 / kg to prepare. BUT One can buy it at a price of Rs.30/kg (retail) with a Cost of production of less than Rs. 20/kg 15-11-2011 A Presentation by VINU FOOD PRODUCTS 13
- 14. 1. Safe and Un-Safe Foods 1.7 An example of Un-safe Food: Pickle type-> Home Made Rs.30 Pickle Difference in ingredients: Lot of OIL, Least OIL Least Water Lot of Water Preserved for months because of: Oil & Salt Added Preservative Rs.30 Pickle saves the cost of oil by adding preservative (Hazardous Contamination) and leaving most of the water content of Mangos/lemons in the pickle. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 14
- 15. 1. Safe and Un-Safe Foods 1.7 An example of Un-safe Food: Where do the Home made Pickle and the Rs.30 pickle fall in the food safety classification Where does the Fungus formed pickle Fall in the classification? 15-11-2011 A Presentation by VINU FOOD PRODUCTS 15
- 16. 1. Safe and Un-Safe Foods 1.7 An example of Un-safe Food: SAFE FOOD HEALTH HAZARD FOOD POISONOUS FOOD 15-11-2011 A Presentation by VINU FOOD PRODUCTS 16
- 17. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: A Safe Food becomes Un-Safe Food (spoiled food) because of: I. Natural decay II. Food Contamination Risk of Un-Safe Food food poisoning of varying intensity. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 17
- 18. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay Food gets spoiled by the following Natural Decay Processes: a) Moisture loss mostly occurs in fruit and vegetables which contain large amounts of water b) Enzyme action in the food c) Rancidity II. Food Contamination 15-11-2011 A Presentation by VINU FOOD PRODUCTS 18
- 19. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination Contamination is the presence of harmful chemicals and micro organisms in food This can cause consumer illness Types of contaminants that makes food Un- Safe: a) Chemicals b) Foreign matter c) Organisms. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 19
- 20. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination a) Chemicals • Naturally Occurring-toxins • Intentionally added -Food additives, Preservatives • Unintentionally added – Agricultural chemicals – Toxic elements and compounds b) Foreign matter c) Organisms. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 20
- 21. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination a) Chemicals b) Foreign matter • Dead insects • Hair • Jewellery • Glass • Metal pieces • Plastic c) Organisms. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 21
- 22. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination a) Chemicals b) Foreign matter c) Organisms. • Bacteria • Yeast • Mold • Viruses • Parasitic Agents 15-11-2011 A Presentation by VINU FOOD PRODUCTS 22 22
- 23. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination a) Chemicals b) Foreign matter c) Organisms. • Bacteria Some bacteria affect • Yeast intestines, causing Mold • Inflammation • • Viruses • Parasitic Agents • Difficulty in absorbing nutrients and water, 15-11-2011 A Presentation by VINU FOOD PRODUCTS 23
- 24. 1. Safe and Un-Safe Foods 1.8 Safe Food to Un-Safe Food: I. Natural decay II. Food Contamination a) Chemicals b) Foreign matter c) Organisms. • Bacteria • Yeast – Some Organisms produce • Mold chemicals that are Toxins • Viruses – They are poisonous to the • Parasitic Agents human digestive system 15-11-2011 A Presentation by VINU FOOD PRODUCTS 24
- 25. 1. Safe and Un-Safe Foods 1.9 Summary of Safe Food to Un-Safe Food: I. Natural decay a) Moisture loss b) Enzyme action in the food c) Rancidity II. Food Contamination a) Chemicals b) Foreign Matter c) Organisms. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 25
- 26. 1. Safe and Un-Safe Foods 1.9 Summary of Safe Food to Un-Safe Food: I. Natural decay a) Moisture loss b) Enzyme action in the food c) Rancidity II. Food Contamination a) Chemicals b) Foreign Matter c) Organisms. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 26
- 27. 1. Safe and Un-Safe Foods 1.10 Preservation of safe food: I. Preventing Contamination II. Preventing multiplication of bacteria, III. Destroying bacteria Are the three basic ways Of preventing Safe Food from becoming Un-Safe Food Let us go through each of them now. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 27
- 28. 1. Safe and Un-Safe Foods 1.10 Preservation of safe food: I. Preventing Contamination • Purchase well packed food items from reliableable suppliers • Maintain good hygiene standards & Minimize handling • Store raw and cooked food separately, • Keep all utensils, kitchen equipments clean, • Cover all food, • Ensure waste is stored and disposed of properly, • Effectively clean and disinfect all surfaces in kitchen II. Preventing multiplication of bacteria, III. Destroying bacteria 15-11-2011 A Presentation by VINU FOOD PRODUCTS 28
- 29. 1. Safe and Un-Safe Foods 1.10 Preservation of safe food: I. Preventing Contamination II. Preventing multiplication of bacteria, – Asepsis – creating a germs free condition – Maintenance of Anaerobic conditions – Use of cold storage – Use of well packed foods within the expire date – Use of chemical preservatives – Drying – Removal of water content III. Destroying bacteria 15-11-2011 A Presentation by VINU FOOD PRODUCTS 29
- 30. 1. Safe and Un-Safe Foods 1.10 Preservation of safe food: I. Preventing Contamination II. Preventing multiplication of bacteria, III. Destroying bacteria – Use of high temperatures including cooking well – Drying – removal of water content – Use of chemical preservatives – Irradiation – Mechanical destruction of microbes – Combination of two or more of the above methods 15-11-2011 A Presentation by VINU FOOD PRODUCTS 30
- 31. 1. Safe and Un-Safe Foods 1.11 Summary of the session: On Food Safety aspects, food is classified into: I. Safe Food II. Health Hazard Food III. Poisonous Food Un-Safe Food Food becomes un-safe due to: I. Natural decay II. Food Contamination Three basic ways to preserve safe food are: I. Preventing Contamination II. Preventing multiplication of bacteria, III. Destroying bacteria 15-11-2011 A Presentation by VINU FOOD PRODUCTS 31
- 32. 15-11-2011 A Presentation by VINU FOOD PRODUCTS 32
Editor's Notes
- Moisture loss mostly occurs in fruit and vegetables which contain large amounts of water. Fruits and vegetables continue to respire after harvesting and therefore lose water through their leaves and skin. Such water could be replaced from the soil through the roots when not harvested. The water retains the structures of the cells of the plants and makes them look fresh. After harvesting, there is no way that the lost water can be replaced so the vegetable or fruit shrinks in size, becomes limp and its skin becomes wrinkled and leathery. Moisture loss occurs in other foods like meat, fish, cheese, due to evaporation of water from the surface. Food spoilage can also come about through the action of enzymes presents in the food. Enzymes are chemicals which are present in all food. They speed up chemical changes that result in loss of flavour, colour and texture. As enzymes are mainly composed of protein, they are sensitive to heat. They are active in temperatures found in a kitchen on a warm sunny day. They can remain very slightly active at very low temperatures such as those found in the freezer. This is why there is a limit to the time food can be stored in a freezer. The activity of these enzymes stops when they are heated above 70 oC. Heat treatment by blanching (i.e. pouring boiling water on the food) is recommended. Some enzymes remain inactive until the food is harvested or slaughtered. Once activated, such enzymes speed up the process of decay by breaking down the tissues and components of the food in the various ways such as oxidation, browning and ripening. Oxidation When Oxidation occurs (i.e. when food comes into contact with oxygen) the enzymes cause the destruction of certain nutrients e.g. vitamin c, thiamine and carotene. Browning Enzymes again cause browning in certain foods the moment they are exposed to air. When you cut or bruise food such as apple or yam, the exposed surface will discolour and turn brownish due to the activity of enzymes. Ripening Enzymes are involved in the process that causes ripening in certain foods such as fruits and vegetables. Unripe bananas for example contain starch which is gradually converted to sugars, until the banana becomes very sweet, and its skin colour changes from green to yellow. Eventually, the skin colour changes to dark brown and it is no longer fit to be consumed. Oxidation - When Oxidation occurs (i.e. when food comes into contact with oxygen) the enzymes cause the destruction of certain nutrients e.g. vitamin c, thiamine and carotene. Browning - Enzymes again cause browning in certain foods the moment they are exposed to air. Ripening - Enzymes are involved in the process that causes ripening in certain foods such as fruits and vegetables. Fermentation - Fermentation , chemical changes in organic substances produced by the action of enzymesAbsorption rancidity : when lipids are stored near strong smelling foods or chemicals making the food unpleasant.Hydrolytic rancidity : Enzymes react with the fats in the food cause sharp, biting, acrid flavour.Oxidative rancidity : oxygen comes in contact with the lipids changes the flavour or odour of dairy products.
- Chemical food poisoning is rare and usually results from accidental ingestion of poisonous chemicals.Agricultural chemicals: e.g. pesticides, fungicides, herbicides fertilizers, antibiotics and growth hormonesToxic elements and compounds: e.g., lead, zinc, arsenic, mercury, cyanide
- Metals can cause food poisoning; if food becomes contaminated with metals such as lead and mercury and is ingested it can cause illness
- Asepsis Keeping out microorganisms, as s preservative factorRemoval of MicroorganismsIt is not very effective in food preservation, but under special conditions it may be helpful. It may be accomplished by means of Filtration, Centrifugation, washing or trimmingMaintenance of Anaerobic conditionsA complete fill, evacuation of the unfilled space, or replacement of the air by carbon dioxide or by an inert gas such as nitrogen will bring anaerobic conditionsPreservation by use of high temperaturesThe killing of microbes by heat is supposed to be caused by the denaturation of the proteins and especially by the inactivation of enzymes required for metabolism. The heat treatment necessary to kill organisms or their spores varies with the kind of organism, its state, and the environment during heating. Classification based on various degrees used Pasteurization, Heating at about 100°C, Heating above 100°CPreservation by use of low temperaturesLow temperatures are used to retard chemical reactions and action of food enzymes and to slow down or stop the growth and activity of microorganisms in food. The lower the temperature, the slower will be the chemical reactions, enzyme action, and microbial growth; a low enough temperature will prevent the growth of any microorganisms. Methods: Common or cellar storage, Chilling or cold storage, Freezing or frozen storagePreservation by dryingDrying usually is accomplished by removal of water, but any method that reduces the amount of available moisture, i.e., lowers the water activity in a food a form of drying. Methods of drying: Solar drying, Drying by mechanical dryers, Freeze drying, Drying during smoking, Other methodsPreservation by Food AdditivesA food additive is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of production, processing, storage or packaging. Food Additives plays an important role in food processing shall discuss later.Preservation by RadiationPossible utilization of radiations of various frequencies, ranging from low-frequency electrical current to high-frequency gamma rays, preservation has been classified as Ultraviolet radiation, Ionizing radiation, Microwave heating.Ultra violet radiationRadiation with wavelengths near 260nm is absorbed strongly by purines and pyrimidines and is therefore the most germicidal. Ultraviolet radiation around 200nm is strongly absorbed by oxygen, may result in the production of ozone, and is ineffective against microbes. Ionizing RadiationsX-rays: Have good penetration ,Effective in sterilization, Economic Gamma rays: Have good penetration, Effective in sterilization, Cobalt 60 being used for commercial applicationCathode rays: Poor penetration, More efficiency than gamma rays, Less health problems than gamma rays
- Asepsis Keeping out microorganisms, as s preservative factorRemoval of MicroorganismsIt is not very effective in food preservation, but under special conditions it may be helpful. It may be accomplished by means of Filtration, Centrifugation, washing or trimmingMaintenance of Anaerobic conditionsA complete fill, evacuation of the unfilled space, or replacement of the air by carbon dioxide or by an inert gas such as nitrogen will bring anaerobic conditionsPreservation by use of high temperaturesThe killing of microbes by heat is supposed to be caused by the denaturation of the proteins and especially by the inactivation of enzymes required for metabolism. The heat treatment necessary to kill organisms or their spores varies with the kind of organism, its state, and the environment during heating. Classification based on various degrees used Pasteurization, Heating at about 100°C, Heating above 100°CPreservation by use of low temperaturesLow temperatures are used to retard chemical reactions and action of food enzymes and to slow down or stop the growth and activity of microorganisms in food. The lower the temperature, the slower will be the chemical reactions, enzyme action, and microbial growth; a low enough temperature will prevent the growth of any microorganisms. Methods: Common or cellar storage, Chilling or cold storage, Freezing or frozen storagePreservation by dryingDrying usually is accomplished by removal of water, but any method that reduces the amount of available moisture, i.e., lowers the water activity in a food a form of drying. Methods of drying: Solar drying, Drying by mechanical dryers, Freeze drying, Drying during smoking, Other methodsPreservation by Food AdditivesA food additive is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of production, processing, storage or packaging. Food Additives plays an important role in food processing shall discuss later.Preservation by RadiationPossible utilization of radiations of various frequencies, ranging from low-frequency electrical current to high-frequency gamma rays, preservation has been classified as Ultraviolet radiation, Ionizing radiation, Microwave heating.Ultra violet radiationRadiation with wavelengths near 260nm is absorbed strongly by purines and pyrimidines and is therefore the most germicidal. Ultraviolet radiation around 200nm is strongly absorbed by oxygen, may result in the production of ozone, and is ineffective against microbes. Ionizing RadiationsX-rays: Have good penetration ,Effective in sterilization, Economic Gamma rays: Have good penetration, Effective in sterilization, Cobalt 60 being used for commercial applicationCathode rays: Poor penetration, More efficiency than gamma rays, Less health problems than gamma rays
- Asepsis Keeping out microorganisms, as s preservative factorRemoval of MicroorganismsIt is not very effective in food preservation, but under special conditions it may be helpful. It may be accomplished by means of Filtration, Centrifugation, washing or trimmingMaintenance of Anaerobic conditionsA complete fill, evacuation of the unfilled space, or replacement of the air by carbon dioxide or by an inert gas such as nitrogen will bring anaerobic conditionsPreservation by use of high temperaturesThe killing of microbes by heat is supposed to be caused by the denaturation of the proteins and especially by the inactivation of enzymes required for metabolism. The heat treatment necessary to kill organisms or their spores varies with the kind of organism, its state, and the environment during heating. Classification based on various degrees used Pasteurization, Heating at about 100°C, Heating above 100°CPreservation by use of low temperaturesLow temperatures are used to retard chemical reactions and action of food enzymes and to slow down or stop the growth and activity of microorganisms in food. The lower the temperature, the slower will be the chemical reactions, enzyme action, and microbial growth; a low enough temperature will prevent the growth of any microorganisms. Methods: Common or cellar storage, Chilling or cold storage, Freezing or frozen storagePreservation by dryingDrying usually is accomplished by removal of water, but any method that reduces the amount of available moisture, i.e., lowers the water activity in a food a form of drying. Methods of drying: Solar drying, Drying by mechanical dryers, Freeze drying, Drying during smoking, Other methodsPreservation by Food AdditivesA food additive is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of production, processing, storage or packaging. Food Additives plays an important role in food processing shall discuss later.Preservation by RadiationPossible utilization of radiations of various frequencies, ranging from low-frequency electrical current to high-frequency gamma rays, preservation has been classified as Ultraviolet radiation, Ionizing radiation, Microwave heating.Ultra violet radiationRadiation with wavelengths near 260nm is absorbed strongly by purines and pyrimidines and is therefore the most germicidal. Ultraviolet radiation around 200nm is strongly absorbed by oxygen, may result in the production of ozone, and is ineffective against microbes. Ionizing RadiationsX-rays: Have good penetration ,Effective in sterilization, Economic Gamma rays: Have good penetration, Effective in sterilization, Cobalt 60 being used for commercial applicationCathode rays: Poor penetration, More efficiency than gamma rays, Less health problems than gamma rays
- Asepsis Keeping out microorganisms, as s preservative factorRemoval of MicroorganismsIt is not very effective in food preservation, but under special conditions it may be helpful. It may be accomplished by means of Filtration, Centrifugation, washing or trimmingMaintenance of Anaerobic conditionsA complete fill, evacuation of the unfilled space, or replacement of the air by carbon dioxide or by an inert gas such as nitrogen will bring anaerobic conditionsPreservation by use of high temperaturesThe killing of microbes by heat is supposed to be caused by the denaturation of the proteins and especially by the inactivation of enzymes required for metabolism. The heat treatment necessary to kill organisms or their spores varies with the kind of organism, its state, and the environment during heating. Classification based on various degrees used Pasteurization, Heating at about 100°C, Heating above 100°CPreservation by use of low temperaturesLow temperatures are used to retard chemical reactions and action of food enzymes and to slow down or stop the growth and activity of microorganisms in food. The lower the temperature, the slower will be the chemical reactions, enzyme action, and microbial growth; a low enough temperature will prevent the growth of any microorganisms. Methods: Common or cellar storage, Chilling or cold storage, Freezing or frozen storagePreservation by dryingDrying usually is accomplished by removal of water, but any method that reduces the amount of available moisture, i.e., lowers the water activity in a food a form of drying. Methods of drying: Solar drying, Drying by mechanical dryers, Freeze drying, Drying during smoking, Other methodsPreservation by Food AdditivesA food additive is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of production, processing, storage or packaging. Food Additives plays an important role in food processing shall discuss later.Preservation by RadiationPossible utilization of radiations of various frequencies, ranging from low-frequency electrical current to high-frequency gamma rays, preservation has been classified as Ultraviolet radiation, Ionizing radiation, Microwave heating.Ultra violet radiationRadiation with wavelengths near 260nm is absorbed strongly by purines and pyrimidines and is therefore the most germicidal. Ultraviolet radiation around 200nm is strongly absorbed by oxygen, may result in the production of ozone, and is ineffective against microbes. Ionizing RadiationsX-rays: Have good penetration ,Effective in sterilization, Economic Gamma rays: Have good penetration, Effective in sterilization, Cobalt 60 being used for commercial applicationCathode rays: Poor penetration, More efficiency than gamma rays, Less health problems than gamma rays
- Asepsis Keeping out microorganisms, as s preservative factorRemoval of MicroorganismsIt is not very effective in food preservation, but under special conditions it may be helpful. It may be accomplished by means of Filtration, Centrifugation, washing or trimmingMaintenance of Anaerobic conditionsA complete fill, evacuation of the unfilled space, or replacement of the air by carbon dioxide or by an inert gas such as nitrogen will bring anaerobic conditionsPreservation by use of high temperaturesThe killing of microbes by heat is supposed to be caused by the denaturation of the proteins and especially by the inactivation of enzymes required for metabolism. The heat treatment necessary to kill organisms or their spores varies with the kind of organism, its state, and the environment during heating. Classification based on various degrees used Pasteurization, Heating at about 100°C, Heating above 100°CPreservation by use of low temperaturesLow temperatures are used to retard chemical reactions and action of food enzymes and to slow down or stop the growth and activity of microorganisms in food. The lower the temperature, the slower will be the chemical reactions, enzyme action, and microbial growth; a low enough temperature will prevent the growth of any microorganisms. Methods: Common or cellar storage, Chilling or cold storage, Freezing or frozen storagePreservation by dryingDrying usually is accomplished by removal of water, but any method that reduces the amount of available moisture, i.e., lowers the water activity in a food a form of drying. Methods of drying: Solar drying, Drying by mechanical dryers, Freeze drying, Drying during smoking, Other methodsPreservation by Food AdditivesA food additive is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of production, processing, storage or packaging. Food Additives plays an important role in food processing shall discuss later.Preservation by RadiationPossible utilization of radiations of various frequencies, ranging from low-frequency electrical current to high-frequency gamma rays, preservation has been classified as Ultraviolet radiation, Ionizing radiation, Microwave heating.Ultra violet radiationRadiation with wavelengths near 260nm is absorbed strongly by purines and pyrimidines and is therefore the most germicidal. Ultraviolet radiation around 200nm is strongly absorbed by oxygen, may result in the production of ozone, and is ineffective against microbes. Ionizing RadiationsX-rays: Have good penetration ,Effective in sterilization, Economic Gamma rays: Have good penetration, Effective in sterilization, Cobalt 60 being used for commercial applicationCathode rays: Poor penetration, More efficiency than gamma rays, Less health problems than gamma rays