NSC 170C1 1st EditionExam 3 Study Guide: Lectures: 16 – 19 & 27Lecture 27 Foodborne Illness: sickness caused by consuming contaminated food or beveragesClasses of Microorganisms - Pathogens: disease-causing microbes including viruses, bacteria, and parasites1. Found on the skin or in the stool or droppings of infected humans and/or animals2. Raw or undercooked meat, poultry, or fish from an infected animal can also expose you to pathogens- Fecal-to-oral transmission: infection caused by putting anything in your mouth (contaminated food or unwashed hands) that has been in contact with fecal matter- Viruses and bacteria are the most common causes of foodborne illness in the United States1. Viruses: microscopic organisms that must have a living “host” such as a plant or animal to surviveExample: Hepatitis A2. Bacteria: microscopic organisms that can exist and flourish on living and nonliving surfaces3. Parasites: microscopic organisms (animals) that take their nourishment from hosts-Found in food and water and often transmitted through fecal-to-oral routePreventing Food-Borne IllnessA. Clean your hands and wash produce 1. Hand washing is one of the most important strategies for preventing foodborne illness2. Wash with warm soapy water and rub hands vigorously for at least 20 seconds3. Thoroughly cleanse anything that touches food (knives, utensils, and countertops) between uses4. Cutting boards: Place in dishwasher or scrub with hot soapy water and rinse. Sanitize by soaking in a solution of 1 teaspoon bleach per 1 quart of warm water5. Sponges and dishcloths: Wash in hot cycle of washing machine with laundry soapand bleach6. Wash fruits and vegetables under cold running tap water before eating. Scrub with vegetable brush if possibleB. Combat cross contamination 1. Cross-contamination: occurs when food that is going to be eaten raw (such as produce) comes into contact with raw meat, fish, or poultry2. Keep separate during food preparation and storage 3. Clean cutting boards thoroughly or use one for meats, poultry, and fish and another for fresh produce and other ready-to-eat foods4. Wash plates that come in contact with raw meats before using them again5. Marinades should not be used as a serving sauce unless boiled for several minutes.a) Do’s and Don’ts of Cross-Contamination-Cook Foods Thoroughly-Color is not a reliable indicator that food is safe to eat-A food thermometer is the only way to determine if food has reached an appropriateinternal temperature to kill pathogens-Food ThermometersC. Cook foods thoroughly D. Chill foods at low enough temperatures 1.Bacteria thrive in environments with the following characteristics:-Adequate nutrients: protein- and nutrient-rich animal foods-Moisture-Low level of acidity: foods with a higher pH 2. The correct temperature: between 40°F and 140°F-Foodborne bacteria multiply most rapidly in the “danger zone”—temperatures between 40°F and 140°F-To keep foods safe, keep hot foods >140°F and cold foods <40°FTime: to reproduce and increase in numbersE. Reduce risk of foodborne illness by practicing proper food handling and storagestrategiesThe 4 Cs of food safety: cleaning, combating cross-contamination, cooking, and chillingPasteurization vs. IrradiationPasteurization: heating foods and liquids to a high enough temperature to kill pathogensIrradiation: foods are placed in a shielded chamber and subjected to a radiant energy source- Most dairy foods and juices in the United States are pasteurized- Can also stop the ripening processin some fruits and vegetables- Kills specific pathogens by breaking up their cells’ DNA- Can also stop the ripening processin some fruits and vegetables-Irradiated foods are not radioactive and do not undergo harmful or dangerous chemical changes.-The temperature of the food isn’t raised, which helps prevent nutrient losses.-Must bear the “radura” logo and the phrase “treated by irradiation” or “treated with radiation” on the package-Canning: packaging food in an airtight container after heating it to kill bacteria-High-pressure processing (HPP): foods are exposed to pulses of high pressure to destroy microorganisms-Modified atmosphere packaging (MAP): manufacturer adjusts the air surrounding the food in a package, usually reducing oxygen to prevent decayFood AdditivesFood additives: substances added to food to preserve freshness, maintain consistency, enhancenutrition content, or prevent rancidity-Salt was the earliest food additive; it preserved meat, fish-Regulated by the FDA since 1958. Manufacturers must document an additive’s safety before it is approved. Exceptions: Prior-sanctioned status: substances known to be safe before 1958 (such as nitrates in meats) Generally recognized as safe (GRAS): substances that have a long history of being safe to consume (such as salt, sugar, spices, vitamins)BioaccumulationMarine toxins: may occur in large fish-Originate in microscopic sea organisms that bioaccumulate in larger fishNeurotoxins: can contaminate shellfish and cause muscle paralysis and death if eaten-Produced by microscopic organisms that cause a “red tide”-Can occur in other foods-Solanine in potatoes exposed to light-Cyanide poisoning from cassava-Contamination is sometimes due to pollutionPolychlorinated biphenyls (PCBs): chemicals that occur in the food supply due to industrial pollution-Used as coolants and lubricants, but banned in 1977 due to concerns of toxicity-Make their way into the environment from hazardous waste sites and improper disposal of consumer products-Don’t break down over time and bioaccumulate in fish-Mercury is a by-product of industrial pollution.-Can accumulate in streams and oceans and be converted to the toxin methyl mercury by bacteria in the waterPesticide- Widely used in agriculture -Can be synthetic or natural -Organophosphates: synthetic pesticides used on crops and residential lawns and plants1. Affects the nervous system of the pests they destroy2. The EPA recently reviewed their safety and concluded they don’t pose a health risk to humans.-Biopesticides: naturally occurring pesticides1. Have both benefits and risks-Can be extremely helpful in preventing growth of fungi and weeds, and controlling damaging insects-Enables crops to flourish and farmers to offer affordable products to the market-Synthetic pesticides can cause unintended harm to animals, the environment, or even humans.1. Depending on