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Unformatted text preview: Notes for Final Exam 1. Food Safety **p 434-480, 7, 57-64, 420-421 Introduction-Areas of concern regarding our food supply-Microbial foodborne illness-Natural toxins in foods-Constitute a hazard whenever people consume single foods either by choice or necessity-Residues in food-Environmental contaminant-Pesticides-Animal drugs Food Safety-Nutrients in foods-More and more artificially constituted foods are appearing on the market-Intentional food additives-Of little concern because so much is known about them that they pose virtually no hazard to consumers and because their use is well regulated-Genetic modification of food Microbial foodborne illness-Commonly called food poisoning-Transmitted to human beings through food and water-Caused by an infectious agent ( foodborne infection ) or a poisonous substance ( food intoxication )-Episodes far outnumber any other kind of food contamination Effects of Food Processing on the Nutrients in Foods-Most forms of processing aim to extend the usable life of a food To preserve a food, a process must prevent three kinds of events-Microbial growth-Oxidative changes-Enzymatic destruction-Occurs as active enzymes in food cells break down their internal molecular structures and cell membranes and cell walls Extended Shelf Life-The secret to these foods’ long shelf life is vacuum packaging or modified atmosphere packaging ( MAP )-preservation technique a perishable food is packaged in a gas-impermeable container from which air has been removed or to which another gas mixture has been added-Excluding oxygen-Slows ripening of fruits and vegetables-Reduces spoilage by mold and bacterial growth-Prevents discoloration of cut vegetables and fruit-Prevents spoilage of fats by rancidity Additives- Indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or other handling. -If a substance is added to a food for a specific purpose in that food, it is referred to as a direct additive. Incidental Food Additives-Indirect or incidental additives are called additives-contaminants from some phase of production, processing, packaging, or consumer preparation-Include tiny bits of plastic, glass, paper, tin and the like from packages and chemicals from processing, such as solvents used to decaffeinate some coffees-Some microwave products are sold in “active packaging” that participates in cooking the food-During the intense heat of cooking, some particles of the packaging components migrate into the food-Regular plastic heats up less, but particles still migrate and might not be entirely safe for consumption Direct Food Additives-Manufacturers use food additives to give foods desirable characteristics-Color, Flavor, Texture, Stability, Enhanced nutrient composition, Resistance to spoilage-Common antimicrobial additives: salt and sugar-withdraw water from food so microbes can’t grow Regulations Governing Additives-The GRAS (Generally Recognized As Safe) List-Many substances were exempted from complying with the FDA procedure when it was first...
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This note was uploaded on 08/01/2008 for the course EDKP 292 taught by Professor Koziris during the Winter '07 term at McGill.
- Winter '07