6. Definition Food Spoilage can be defined as undesirable changes occurring in food, making it unfit & unacceptable for human consumption.
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11. 2. Chemical reactions due to contact with metal :- Foods of acidic or alkaline nature may react with metal container leading to undesirable change. Example : Butter milk kept in brass vessel.
12. 3. Micro-organism :- Growth & Multiplication of micro-organisms leads to food spoilage. Example : Yeast, bacteria etc contaminate the food which cause food poisoning.
13. 4. Insects, rodents, birds :- Foods are mechanically damaged by insects, rodents, birds, etc. Example : The holes on surface of tomatoes, cucumber, brinjal indicate that they are harboring larvae of insects.
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15. 3. Physical, environmental Factors – Temperature, PH value of food influence microbial activity. 4. Availability of Oxygen – Most of the micro-organism require oxygen for their growth such micro-organism are called ‘Aerobic’ micro-organisms and those which do not require oxygen for their growth are called ‘Anaerobic ’ micro-organisms .
16. Food Preservation A process by which certain foods like fruits & vegetables are prevented from getting spoilt for a long period of time.
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19. 2. Preventing self decomposition of Food a) Destroying enzymes in Food : Enzymes found in food can be inactivated by changing their conditions such as temperature & moisture. b) Preventing auto-oxidation : by adding antioxidants. 3. Removal of insects, rodents, birds, etc : By proper storage, use of permissible insects repellants.
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23. Evaluation 1. Define Food spoilage Ans : Food spoilage can be defined as undesirable changes occurring in food, making it unfit & unacceptable for human consumption.
24. 2. What are the extrinsic factors causing Food spoilage Ans : Extrinsic Factors : a) Mechanical damage b) Chemical reactions due to contact with metal c) Micro-organisms d) Insects, rodents, birds, etc.
25. 3. What are the methods of Food Preservation Ans : a) Keeping out of micro-organisms b) Use of high temperature c) Use of low temperature d) Drying e) Preservatives f) Irradiation