A SAFE FOOD SUPPLY? Is Your Food Safe to Eat? Mr. Johnson Central Heights Ag Dept.

Student Objectives n Analyze the risk involved in the use of pesticides in food production. n Evaluate the risk of using hormones and antibiotics on animals raised for food. n Explain the safeguards to prevent harmful pesticides residues on food. n Describe the use the body makes of cholesterol.

Student Objectives n Describe the safeguards used in the meatpacking industry. n Discuss the use of chemical preservatives in food. n Distinguish the difference between saturated and unsaturated fats.

Food SAFETY???? n Americans enjoy an abundant, diverse, and relatively inexpensive food supply. n Most people are not involved with the production and processing of the food they eat.

Does the media make the food unhealthily? n In the past few years the media has reported that foods or components of the food that we eat are either unhealthy or hazardous to our health.

Rumors Spread FAST!!! n It is easy to forget that properly conducted and reported scientific research is responsible for the abundant, safe supply of food we enjoy. n Inconclusive or poorly reported research can often mislead the public. n Poorly reported research can cause prices to drop within minutes.

Pesticides and Chemicals n In 1989, the Natural resources defense Council published a report entitled “Intolerable Risk: Pesticides in our Children's Food.” n The report stated that a chemical called Alar that was used to prevent apples from falling from the tree to early. Which allows the fruit to have a better shape and color.

APPLES KILL CHILDREN!!! n According to reports when the chemical was feed to lab rats it was proven to be carcinogenic. n This caused panic! n Apples were dumped n Banned from schools

The Damage was DONE. n Apples were removed from sale. n The apple industry suffered a tremendous result more than a $100 million Dollars!! n It was poorly presented information- In fact a person would have to eat 28,000lb of apples a day for 10 yr.. to equal the amt.. of Alar that caused the tumors in the lab rats.

Chemicals n Even though the chemical Alar was considered safe in low amounts it was still pulled off the market. n A chemical must pass over a 120 separate test before it can be released for use. n On Average only one in 20,000 chemicals are approved for use ag producers.

So are pesticides harmful to humans? n Pesticides kill insects, weeds, and plant disease organisms. n Modern insecticides, fungicides, and herbicides have a low level of toxicity to humans. n Even at full strength it would take a a lot to be lethal.

Allowable levels? n Allowable levels are measured in parts per billion or parts per trillion. n Almost all substances can be toxic or hazardous at some level. n Salt is a necessary component of our diets but if some one ate enough salt they would die from a salt overdose.

To be organic; or not to be? n A recent trend is to eat organically grown food.(Food that is grown without pesticides or herbicides.) n Some people feel that this is safer food but research shows no advantage. In fact there are more disadvantages. n Natural toxins, Cost, Damage caused by insects can harbor bacteria which can be more harmful than the pesticides

MEAT INSPECTION n All meat sold to the public must be inspected. n Quality grading refers to the quality of the meat- determined by Age and intermuscular fat.

Meat inspection cont. n Yield grading refers to the amount of lean retail cuts the carcass will yield. n Meat inspection guarantees that the meat will be safe, wholesome, and accurately labeled. n Meat inspection includes several phases. n Live inspection- ante-mortem. n Internal organs are inspected.

Meat inspection cont. n When carcasses and/or part fail inspection, they are condemned. n Condemned carcasses go through a process called rendering. n Rendering is where the condemned are placed under enough heat to kill any organism that could cause problems.

Meat inspection cont. n Rendered meat is used for by-products other than for human consumption. n Each slaughter house is inspected for cleanliness and free of bacteria, ect... n In the processing line, all carcasses must be thoroughly cleaned to remove debris from the slaughter process; blood, loose tissue particles, or foreign particles.

Meat inspection cont. n If meat becomes contaminated by fecal matter, ect.., that portion of the carcass are trimmed. n With best measures, meat will still contain bacteria and other microbes. n For that reason it is important that meat is thoroughly cooked before consumption. n Almost all of the sickness caused from eating meat can be attributed to improper cooking procedures.

Hormones and Antibiotic Residues n An area of consumer concern is the use of synthentic growth and reproductive hormones in beef and dairy animals. n The concern is that this will cause harmful effects in humans. n Growth hormones redirects energy from the production of fat to the production of lean. n More weight is gained at lower cost and is more efficient and healthier.

Hormones and Antibiotics cont. n The hormone is placed under the skin in the animal’s ear and are slowly released as the animal grows. n The ear is removes at slaughter to prevent residue from accumulating in the edible meat. n Livestock and poultry industries use antibiotics to cure or prevent diseases. n The concern is that pathogens can build up an immunity to the drugs, as a result of residue of the drugs in the meat.

Hormones and Antibiotics cont. n According to the National Academy of Science, no data has been found that implicates the use of antibiotics in animals used for food as a health risk to humans. n Another concern for humans in the dairy industry is using bovine somatotropin, (BST). n This natural hormone stimulates cows to produce more milk.

Hormones and Antibiotics cont. n The concern is that the use of BST is a health risk, but there is no evidence to support that. n In fact, milk from cows treated with BST is almost identical as cows with out BST. n BST is a protein and can be digested and is not passed into the systems of humans. n The FDA closely monitors meat, dairy products and all food from animals for residues of pesticides, drugs, and hormones.

Hormones and Antibiotics cont. n If levels are detected that go beyond safe tolerances, that product is condemned at the producer’s expense. n This gives producers incentives to adhere to the guidelines and withdrawal periods. n A withdrawal period is the time between when the substance was administered to the animal until the animal can be slaughtered or the milk used.

Preservatives n Many people are concerned over adding preservatives such as nitrates, citric acid, sodium benzonate, and phosphoric acid to foods. n The purpose of these additives is to prevent the formation of toxic substances associated with the spoilage of food. n These foods are susceptible to the growth of bacteria that can cause food poisoning.

Preservatives cont. n The likelihood of any health problems arising from chemical preservatives added to foods is insignificant compared to the food poisoning that can occur in untreated food.

Fat Content in Food n Studies have shown a relationship between diets high in fat and health problems (obesity, heart disease, cancer, etc.) n Concern has been expressed over eating red meat because of the high amount of fat and also because of the cholesterol content.

Fat Content in Food cont. n Both fat and cholesterol are necessary components of human diets, but excessive amounts of either can cause problems. n Fats are divided into two broad classifications saturated fat and unsaturated fat. n Unsaturated fats are in a liquid state at room temp. n Saturated fats are in a solid state at room temp.

Fat Content in Food cont. n Eating red meats from animals such as cattle and sheep is safe as long as the amounts are moderate and are part of a balanced diet.

Labeling of Foods n President Roosevelt passed the Federal Food and Drug Act and the Federal Meat Inspection Act. These laws were the first steps in the regulation of the food industry as to the safety and quality of foods. n Laws regarding the processing and labeling of foods have continually been upgraded and improved since that time.

Nutritional Labeling n About 90% of all processed foods must have nutritional labeling on the package. n Exceptions- –Coffee –Tea –Flavorings that contain no significant amounts of nutrients n The nutritive content of the food is expressed in terms of Daily Value (DV) n The DV refers to the percent of the nutrient in the food that is recommended based on a 2,000 calorie diet.

Summary n Foods are safer now than at any time in history. n Improper cooking, spoilage, and mishandling of the foods by the consumer are by far the biggest causes of food safety problems.

The Science of Food Preservation

Causes of Food Spoilage (But What About Bacteria?!) n Microbes - extremely small organisms. –Louis Pasteur discovered the presence of microbes and brought about the process known as pasteurization (this renders the microbes in milk harmless) n Bacteria- microbes that are responsible for much of the decay and spoilage of the plant and animal tissue in foods. –Bacteria makes the food not fit to eat because of the smell and taste and can often be dangerous.

Causes of Food Spoilage cont. n Molds- microbes that also aid in the breakdown of plant and animal tissues. –Toxins from molds are called mycotoxins and may cause illness when consumed. –Molds appear as fine, hairy fillaments on the surfaces. n Yeasts- single- celled fungi. –Used extensively in the fermentation of carbohydrates. –Many yeasts are beneficial, but they may also cause food spoilage by growing on the food.

Chemical Causes of Food Spoilage n Enzymes can cause sugars to turn into fats or may cause proteins or fats to change in makeup or function. n Up to a point, certain enzymatic changes are desirable in that they trigger the creation of sugars in the ripening process.

Chemical Causes cont. n Rancidity is a chemical process that takes place in fats that causes food spoilage. n Hydrolytic rancidity comes about as a result of reactions of the fatty acids with water molecules.

Food Preservation in Fresh Foods n After fruit has been picked, washed, and cleaned, they are coated with a thin layer of paraffin to prevent damage to the skin. n In a process called controlled- atmosphere storage, the respiration of the fruit cells is controlled. They are placed in dark chambers with controlled temps. n This keeps some fruit fresh for many months

Food Preservation by Drying n The first method of preserving food was drying. n If the water is removed from food, the microbes and enzymes are unable to live and reproduce. n The most modern technique of drying is freeze-drying.In this process, the product is quickly frozen and placed in a chamber where a vacuum is drawn. This allows the water molecules to go almost directly from ice to vapor.

Food Preservation by Salting n By covering meat with salts, the water in microbes passes to the salt and the microbes dry out and die. n Sugar can also be used as a preservative because the same principal applies. n The problem with salting is removing the salt from the food being preserved. n Therefore, the only foods preserved in salt today are those such as fat back and salt pork.

Food Preservation by Fermentation and Pickling n Solutions high in salt and vinegar give the advantages of the salt solution dehydrating the microbes and the vinegar lowering the pH to a level intolerable to the microbes.

Food Preservation by Freezing n Early iceboxes that were used, cooled food with a large block of ice stored in the compartment with the food. n Microbes cannot live well in cool temperatures, so the food can be preserved longer.