sansatation and spoilage

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Ask the students when was the last time they washed their hands. Tell them to look at their hands and notice the natural lines, cracks, and wrinkles. These are the perfect places for dirt and germs to hang out. Give each student a magnifying glass. Have the students use the magnifying glasses to examine their hands more closely. Ask them what they see. They should be able to better see the natural cracks, lines, and wrinkles of their hands, and they may also be able to see some dirt on their hands. Tell them that no matter how hard they look, they will not see any germs. Germs are microorganisms that can only be seen with a microscope. Just because they can’t see them, however, does not mean that they aren’t there. Inform the students that germs live everywhere and billions of them grow and live on their bodies every day. Most of these germs are not harmful, but the germs we pick up from everything around us can be harmful. Many of them can make us sick. If these harmful germs get onto our food, they can spread and cause food poisoning. We must wash our hands frequently and do whatever else we can to prevent spreading harmful germs that can make us sick.

1

Discuss food safety.

2

Outline safe food handling.

3

Name methods of food preservation.

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Aseptic packaging Blanching Canning Contamination Curing Dehydration Fermentation Food-borne illness Food preservation Food spoilage Freezing

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Irradiation Paraffin Pasteurization Pathogen Perishable food Pickling Refrigeration Sterilization Vacuum wrapping Wholesome food

 Anticipated

Problem: How do we guarantee safe food?

 I. Food

is an essential component in our lives. Food provides the nutrients required for us to live. Steps must be taken to keep our food safe for us to eat.

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A. Food safety is very important to insure that the foods we eat are wholesome. Wholesome food is food that is nutritious and safe to eat. Wholesome food does not contain foreign substances that could make us sick. Spoiled food or food with foreign substances in it is unwholesome. Unwholesome food may cause sickness.

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B. A food-borne illness is an illness that results from eating unwholesome food. 1. Symptoms of food-borne illness include fever, vomiting, diarrhea, abdominal cramps, and headache. 2. About 76 million people become ill each year from the food they eat. Of those, 325,000 need to be hospitalized. 3. About 5,000 people die each year from food-borne illness. 4. It is estimated that proper hand washing could eliminate over half of the cases of food borne illness. 5. At least 85% of food-borne illnesses can be avoided by handling food properly. 6. Bacteria such as Salmonella, E. coli, and Clostridium botulism are common causes of food-borne illness.

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C. Food spoilage is a condition in which food becomes unsafe to eat. The food may be decaying. Most food spoilage is caused by bacteria and fungi. Food that is spoiled is not safe to eat. D. Food must be handled safely to avoid contamination. Contamination is the addition of something unwholesome or undesirable. Contaminated food is not safe to eat. E. To keep food safe, it must be properly handled throughout the food chain, from the farm to the consumer.

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F. Some foods must be packaged and stored differently to prevent spoilage because they do not keep as well as others. Perishable food is food that is highly susceptible to spoilage and must be consumed in a short period of time. All types of food will eventually spoil if they are not preserved, but some foods are more perishable than others. Bread, meat, and dairy products, for example, are more perishable than grains and nuts.

 G. Temperature

is very important in preventing illness from pathogens. A pathogen is a contaminant that causes sickness. Bacteria, molds, and fungi are common pathogens. Most pathogens can only live in temperatures between 40°F and 140°F. Pathogens cannot be seen or smelled. When a product looks or smells bad, then it is already too late.

 H. Government

regulations help insure that our food is safe. The United States Department of Agriculture (USDA) is responsible for inspecting food. The Federal Food and Drug Administration (FDA) monitors the food supply to make sure that all laws are being followed.

 Anticipated

Problem: How do you handle food properly?

 II. Handling

food properly keeps our food safe and helps reduce the risk of foodborne illness. The Four Cs of Food Safety can be used as guidelines for handling food safely—clean, cook, combat crosscontamination, and chill.

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A. Clean—

1. Wash your hands, all utensils, and surfaces in warm soapy water before and after preparing food, especially after handling raw meat, poultry, eggs, or seafood.  2. Rinse raw produce under running water. Cut off any bruised or damaged areas.  3. Use paper towels for cleaning up kitchen surfaces, and throw them away when done. If cloth towels are used, wash them often in the hot cycle of your washing machine. 

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B. Cook—

1. Cook food to the proper temperature. You cannot tell if food is properly cooked just by looking at the color.  2. Use a clean meat thermometer to check the temperature of meat. All meat should be cooked to the proper temperature. Seafood should be cooked until opaque. Cook eggs until they are firm and no liquid remains.  3. All leftovers should be reheated to 165°F. 

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C. Combat Cross-Contamination— 1. Raw meat, poultry, and seafood should be sealed and kept separate from other foods in your refrigerator to avoid contamination. 2. Either clean cutting boards thoroughly between uses or use different cutting boards for meats and fresh produce. 3. Wash your hands, cutting boards, dishes, and utensils after use. 4. Do not place cooked food on the same dish where raw food was held. 5. Do not use sauces that were used for marinating raw meat unless you boil them first.

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D. Chill—

1. Refrigerate food at 40°F or lower. 2. Refrigerate leftover food as soon as possible but always within two hours. 3. Put leftovers in shallow containers for quick cooling. 4. Marinate and thaw foods in the refrigerator, not on the counter or in the sink at room temperature. 5. Do not pack the refrigerator too full because it does not allow cold air to circulate. 6. Pack coolers full and with plenty of ice to keep foods cool at picnics or barbeques.

 Anticipated

Problem: What are some methods of food preservation?

 III. Food

preservation is the treatment of food to keep it from spoiling. Food preservation can be accomplished by several methods.

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A. Canning is a method of food preservation in which food is placed in a container and heated at high temperatures under pressure to kill all microorganisms. The food containers are held at the right temperature for a period of time and then cooled. An airtight seal must be created on the container to keep microorganisms from getting back into the container after it cools. Vegetables, fruits, and meats can be canned.

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B. Freezing is a preservation method in which foods are stored at a low temperature so the water in the product becomes ice. Most microbial activity stops when frozen. Fruits, vegetables, and meat can all be frozen. Foods should be prepared carefully for freezing. 1. Only food free of decay should be frozen. 2. Most fruits and vegetables are blanched before freezing. Blanching is a heat treatment designed to raise the temperature of food between 180°F to 190°F followed by rapid cooling. Blanching does not destroy microorganisms. It inactivates enzymes that can alter the taste and color of a food product.

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C. Fermentation is a method of food preservation that uses the carefully controlled activity of certain bacteria, molds, and yeasts. Fermentation is used in making wines, breads, vinegars, and cheeses. D. Dehydration, or drying, is a method of preservation that involves the removal of all the moisture from a food product. Microbes require moisture to function, so removing the water ends their activity. Fruits and meats are often dehydrated. Raisins and beef jerky are examples of dried foods.

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E. Curing is a food preservation method in which substances that prevent microorganism growth are added to foods to prevent spoilage. Concentrations of salt, sugar, sodium nitrate, and other materials are used for curing. Meats are often cured. F. Refrigeration is a method of food preservation that involves storing foods between freezing and room temperature. Refrigeration does not kill any microorganisms, but it slows down their growth. Many foods are refrigerated temporarily.

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G. Pasteurization is a heat treatment that kills all pathogenic microorganisms (ones that cause illness) but does not kill all spoilage microorganisms. All milk in stores has been pasteurized. H. Irradiation is a food preservation method in which foods are treated with electrically charged particles, such as X-rays, electron beams, or gamma rays. Low amounts of radiation will kill spoilage organisms. Meats and fruits are often irradiated.

 I. Special

packaging can be used to preserve food.

 2. Vacuum

wrapping is a method of food preservation in which all oxygen is removed from the food’s packaging. Microorganisms cannot grow without oxygen. Vacuum wrapped foods can be stored for quite some time at the proper temperature without spoiling.

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J. Pickling is a food preservation method that prevents the growth of spoilage organisms by placing foods in acid solutions. Vinegar is commonly used for pickling. Cucumbers, cauliflower, okra, peppers, other vegetables, and some meat products are pickled. K. A thin layer of paraffin, a type of wax, can be applied to some foods to preserve them. The paraffin holds moisture in and keeps organisms out. Apples and rutabagas are commonly coated with a thin layer of paraffin.

1. How

do we guarantee safe food?

2. How

do you handle food properly?

3. What

are some methods of food preservation?