FOOD SCIENCE AND NUTRITION

There are several reasons why food preservation is important:

1. To extend the shelf life of food: Food preservation techniques can help extend the shelf life of food, allowing it to be stored for longer periods of time without spoiling.
2. To prevent food waste: Food preservation can help reduce food waste by allowing food to be stored and consumed at a later time.
3. To prevent food poisoning: Proper food preservation techniques can help prevent the growth of bacteria and other microorganisms that can cause food poisoning.
4. To maintain the nutritional value of food: Some food preservation techniques, such as freezing and canning, can help maintain the nutritional value of food by preserving vitamins and minerals.
5. To improve the availability of food: Food preservation techniques can help improve the availability of food, especially in areas where food is scarce or not readily available.

1. Bread: Yeast, a type of microorganism, is used in the production of bread to cause fermentation and give bread its distinctive texture and flavor.
2. Cheese: Many types of cheese are produced using microorganisms such as bacteria and moulds. For example, penicillium mould is used in the production of blue cheese, while bacteria such as Lactobacillus and Streptococcus are used to produce cheddar and other types of cheese.
3. Yogurt: Yogurt is produced using bacteria such as Lactobacillus and Streptococcus, which ferment milk to produce lactic acid.
4. Pickles: Pickles are produced using bacteria such as Lactobacillus, which ferment the vegetables and give them their distinctive sour taste.
5. Soy sauce: Soy sauce is produced using a combination of soybeans, wheat, and a type of mould called Aspergillus oryzae.
6. Alcoholic beverages: Many alcoholic beverages, such as beer, wine, and spirits, are produced using microorganisms such as yeast and bacteria. These microorganisms ferment sugars to produce alcohol.

1. Moulds: Moulds are a type of fungus that can grow on food and cause food poisoning. Moulds can produce toxins called mycotoxins, which can be harmful if ingested. Moulds can grow on a variety of foods, including meats, grains, and fruits.
2. Bacteria: Bacteria are single-celled microorganisms that can cause food poisoning. There are many different types of bacteria that can contaminate food, including Salmonella, E. coli, and Listeria. When these bacteria are ingested, they can multiply in the body and produce toxins that cause symptoms such as nausea, vomiting, diarrhea, and abdominal cramps. Bacteria can contaminate food through poor hygiene practices, such as failing to wash hands or utensils before handling food.

1. Poor personal hygiene: Food handlers who do not practice good personal hygiene, such as washing their hands frequently and properly, may contaminate food with bacteria from their skin or respiratory tract.
2. Handling food with bare hands: Food handlers who handle food with their bare hands, rather than using utensils or gloves, may transfer bacteria from their hands to the food.
3. Cross-contamination: Food handlers who do not properly store or handle raw and cooked foods separately may contribute to cross-contamination, which occurs when bacteria from raw food are transferred to cooked food.
4. Using contaminated equipment: Food handlers who use equipment or utensils that are not properly cleaned and sanitized may contribute to the spread of bacteria.
5. Working while sick: Food handlers who work while sick, particularly with a diarrheal illness, may contaminate food with bacteria from their respiratory or digestive tracts.
6. Improper storage: Food handlers who do not store food at the proper temperature or in a clean and dry environment may contribute to the growth of bacteria in the food.

Irradiation is a process in which food is exposed to ionizing radiation in order to kill bacteria, viruses, and other microorganisms. Irradiation is used in food preservation for a variety of purposes, including:

1. Increasing shelf life: By killing microorganisms, irradiation can help to extend the shelf life of certain foods, such as fresh fruits and vegetables, meats, and grains.
2. Reducing the risk of foodborne illness: Irradiation can help to reduce the risk of foodborne illness by killing harmful microorganisms that may be present in food.
3. Reducing the need for chemicals: Irradiation can be used as an alternative to chemical preservatives, such as sodium benzoate or sulfur dioxide, which may have negative effects on human health or the environment.
4. Protecting against pests: Irradiation can be used to kill insects and other pests that may be present in food, such as stored grains or dried spices.
5. Improving the safety of imported foods: Irradiation can be used to improve the safety of imported foods, which may be exposed to a variety of microorganisms during transportation and storage.