Summary - In this Chapter we will examine the safety of the foods and food products available in our society. As well we will examine how authorities in our country try to protect us against hazards which might be found in our food supply. In this chapter we will investigate the risks associated with Microbial Food Poisoning, Natural Toxins in Foods, Chemical Residues in Foods, Nutrient Content of Foods, and Chemical Additives.

Microbial Food Poisoning is a general term used to cover any illness caused by these organisms. Two kinds of poisoning exist, infections and intoxications.

Infectious diseases happen when an invading organism actually grows in the host, and the presence of the organism causes disease symptoms. When this happens we say we have a food borne infection. Hepatitis, salmonella dysentery and tapeworms are examples of food borne infections.

Intoxications happen when we consume some poisonous material. If that poisonous material was produced by a microorganism, we say we have contracted a microbial intoxication. Staphylococcus aureus and Clostridium botulinum are two dangerous toxin producing bacteria. You do not need to consume live organisms to get an intoxication, only some of the toxin.

Occurs from any foreign environmental contaminant in food.  This type of poisoning has tremendous potential for harm.  Some contaminants are short lived, however, others can resist breakdown and can linger to interact with the body's system. This section of the Chapter attempts to categorize the vast array of chemicals which are potential hazards to man through contamination of the food supply. The purpose is just to provide students with an overview of the classes of chemicals.

Radioactive isotopes -

Manmade - Fallout and accidents result in isotopes being loosed in the environment, and thus getting into food.

Natural - Tobacco and nuts are among several plant that actually accumulate radioactive materials from soil that they are grown on, if the isotope is present.

Residues of Agricultural Chemicals -

Pesticides - residues can be left on fruits and vegetables.

Antibiotics, hormones and medical compounds can be found in animals improperly treated for disease with these compounds.

Post-harvest spray chemicals - these are used to keep foods from spoiling before reaching the market place. Sometimes these can remain on the food.

Heavy metals and trace elements

Lead - A hazard to humans from several sources which were discussed in Chapter 13.  These include paint, pottery, pipes, pets, and pollution.

Mercury - Found its way into the food supply when industry released it into waterways and it accumulated in popular seafood.

Cadmium - Used in industrial processes such as plastics, batteries, smelters.   Others sources are cigarette smoke and ash from volcanic eruptions.

Other environmental contaminants

Detergents - These are found under your sink, and in food processing plants. Accidents can happen in both places, and detergents can get in to foods.

Sanitizers - Antibacterial compounds are used widely in some food processing plants. These can get into food.

Greases, oils and fuels - Machinery needs lubricants, food processing machinery is no exception. These can drip into cans or onto foods if we are less than vigilant.

Adhesives - Food boxes and packaging have glue and adhesives on them These can get into food.

Colors - Many labels have dyes and inks for colorful advertising and identification. These can get into food.

Metals - Metals bits often flake off of rollers, crushers and conveyers, and fall into foods.

Home - Keep it cool, clean and covered, and cook it well before you eat it!   Proper handling of raw foods, especially meats, are now listed on packages.   These labels help educate home cooks so they can reduce food poisoning.  Of concern are the "occasional quantity cooks".  Keeping large amounts of food at the proper temperature can be tricky, yet the consequences of not doing so can be big!

Troublesome Foods include meats and poultry, eggs, seafood, picnic foods, honey.

Potatoes - can have solanines, green colored alkaloids which are produced by the tuber in response to sunlight. There can be enough solanines in a peck of potatoes to kill a horse!

Almonds, lima beans, peach pits, cassava - Cyanogenic glycosides that can release cyanide when eaten.

Cabbage and Cauliflower - Goitrigens are found in these plants, which cause hyperthyroidism.

Nutmeg - Myristicin is a hallucinogen found in nutmeg.

Soy beans - contain a host of anti-digestive, anti-vitamin, anti-mineral, anti-red blood cell; and allergenic chemicals.

Rhubarb leaves, watercress and spinach - have high oxalate content, which prevent Calcium absorption.                             

Wild mushrooms - neurotoxins present in mushrooms have deadly effects.

Red Tide is a bloom which contaminates seafood and can cause paralysis - found in algae.

The list is endless.

Freezing -  This does not alter the nutrient composition to much, however, they need to be stored below 32 Fahrenheit or 0 Celsius.

Drying -  Heat dried foods can have dramatic nutrient loss from processing, but vacuum puff drying and freeze drying conserve nutrients quite well.

Food Additives - Substances that are added to foods, but are not normally consumed by themselves as food.

Antimicrobials - examples are acetic acid, sodium chloride, benzoic acid, nitrites, and sulfur dioxide.

Antioxidants - are preservatives that prevent rancidity of fats in foods and other damage to foods caused by oxygen, such as vitamin E and C, BHA and BHT.

Colors - are used to enhance appearance of food.  These can be vegetable derived colors, or synthetic colors.

Flavors -  are chemicals that mimic natural flavors or enhance flavors.

Nutrient Additives -  are nutrients added to food to improve the nutrient value.

Food Preservation history can be divided into three rough eras:

• The Pre-industrial Era
• The Industrial Era
• The Modern Era

See the movies at left for further information on this topic.

The Safety of the New Technologies -

Bioengineering - This technology has changed traditional agriculture by creating strains of corn that stay sweeter longer after being picked; by increasing resistance of some crops to disease; by recruiting microorganisms to produce substances in much greater amounts than what occurs in nature; and by developing crops that resist destruction by herbicides.  

Symbol for foods treated with radiation

Food Irradiation - The technology involves exposing foods to controlled doses of gamma rays from the radioactive compound cobalt 60 or from X rays generated by machines.  This procedure can delay spoilage by inactivating cells, or by destroying microorganisms.  Irradiation does effect nutrient value, especially the antioxidant vitamins.  Any free radicals generated by irradiation can be quenched by an antioxidant, thus using up this property.  This effect is very minimal and affects the nutrient content about as much as canning.

Safety concerns exist for both the food and those people exposed to the radioactive materials during processing and disposal.  It appears more time is necessary to fully understand this technology and to get consumer acceptance.