FUNCTIONS AND USAGE OF FOOD ADDITIVES

II. FUNCTIONS AND USAGE OF FOOD ADDITIVES

A. Functions

Hundreds of chemical additives are incorporated into foods directly or migrate into foods from the environment or packaging materials. A food additive can be sometimes defined as a substance whose intended use will lead to its incorporation into the food or will affect the characteristics of the food. These additives generally provide some type of benefit to the food producer, processor, or consumer. For the consumer, additives can improve organoleptic qualities of foods, improve the nutritive value, or ease the preparation of ingredients and meals. Typical additive benefits to the food producer or processor include improving product quality, safety, and variety.

Additives may be found in varying quantities in foods, perform different functions in foods and ingredients, and function synergistically with other additives. Their functions can usually be classified as one of the following: (1) to maintain or improve nutritional quality, (2) to maintain or improve product safety or quality, (3) to aid in processing or preparation, and (4) to enhance sensory characteristics (FDA, 1979, 1992). Additives that affect nutritional quality are primarily vitamins and minerals. In some foods, these may

be added to enrich the food or replace nutrients that may have been lost during processing. In other foods, vitamins and minerals may be added for fortification in order to supplement nutrients that may often be lacking in human diets. Preservatives or antimicrobial sub- stances are used to prevent bacterial and fungal growth in foods. These additives can delay spoilage or extend the shelf life of the finished product. Antioxidants are additives that also can extend the shelf life of foods by delaying rancidity or lipid oxidation. Additives that maintain product quality may also ensure food product safety for the consumer. For example, acids that may be added to prevent the growth of microorganisms that cause spoilage may also prevent the growth of microorganisms that can cause foodborne illness. Additives that are used as processing or preparation aids usually affect the texture of ingredients and finished foods. Some of these are classified as emulsifiers, stabilizers, thickeners, leavening agents, humectants, and anticaking agents. Chemicals in this group of food additives are also used to adjust the homogeneity, stability, and volume of foods. The fourth major function of food additives is to enhance the flavor or color of foods to be added to enrich the food or replace nutrients that may have been lost during processing. In other foods, vitamins and minerals may be added for fortification in order to supplement nutrients that may often be lacking in human diets. Preservatives or antimicrobial sub- stances are used to prevent bacterial and fungal growth in foods. These additives can delay spoilage or extend the shelf life of the finished product. Antioxidants are additives that also can extend the shelf life of foods by delaying rancidity or lipid oxidation. Additives that maintain product quality may also ensure food product safety for the consumer. For example, acids that may be added to prevent the growth of microorganisms that cause spoilage may also prevent the growth of microorganisms that can cause foodborne illness. Additives that are used as processing or preparation aids usually affect the texture of ingredients and finished foods. Some of these are classified as emulsifiers, stabilizers, thickeners, leavening agents, humectants, and anticaking agents. Chemicals in this group of food additives are also used to adjust the homogeneity, stability, and volume of foods. The fourth major function of food additives is to enhance the flavor or color of foods to

B. Usage

Chemicals that are added to foods may be manmade or derived from natural plant or animal sources. Also, additives may be synthesized for foods that are chemically or func- tionally identical to those that may be derived from natural sources. In the case of color additives, synthetic colors are also identified as certifiable colors. Each batch of these coloring chemicals is tested by the manufacturer and the U.S. Food and Drug Administra- tion to ensure the safety, quality, consistency, and strength of the color additive prior to its use in foods. Currently, nine synthetic color additives may be added to foods. Color additives that are exempt from this certification process include pigments derived from natural sources such as vegetables, minerals or animals, or the manmade equivalents of naturally derived colors. Examples include annatto extract, paprika, turmeric, and beet powder.

Substances that are considered food additives may be naturally occurring in some foods and ingredients or artificially added to other foods. If an additive from a natural source is added to a food, then its package label may state that the additive is ‘‘artificially added’’ since it normally is not found in the food. Additives are further classified by how they are added to foods. Some additives are directly added to foods and ingredients, while others may be added indirectly through contact with packaging materials as are, for exam- ple, the preservatives BHA and BHT on the inside of breakfast cereal bags. Water is usually considered to be a food ingredient when added during the manufacturing process, but it can be considered a direct additive, too. For example, in poultry processing in the United States, trimmed and washed carcasses are immersed in a cold water ‘‘chiller tank’’ for approximately one to two hours to reduce carcass temperature. During this time, the carcasses may gain weight when they absorb water from the tank. At this time, regulators are debating whether to mandate that processed poultry be labeled to state that water (and weight) has been added to the product.

Some undesirable food additives may be unintentionally added to foods. For exam- ple, pesticides and fumigants may come in contact with produce and grains during grow- ing, harvesting, and storage. While these chemicals may have permitted uses for some crops, they may be illegal for use on others. Sometimes pesticides are mistakenly or unin- tentionally applied at the wrong concentration or too soon before harvest. Pesticides have been found, infrequently, on certain crops and at certain concentrations that are not permit- ted by the Environmental Protection Agency. Other examples of unintentional addition of food chemicals are those that migrate into foods from packaging materials, especially plastics, and those that occur from poor storage practices. Numerous chemicals may find their way into foods through contamination from the environment. Frequently cited exam- ples include dioxin, polychlorinated biphenyl compounds (PCBs), and heavy metals such as lead and mercury.

Food additives are generally intended to provide important benefits to the producer or consumer of foods. But sometimes these additives cause unwanted or unhealthful ef- fects. Often these undesirable effects of food additives are due to their excessive or acci- Food additives are generally intended to provide important benefits to the producer or consumer of foods. But sometimes these additives cause unwanted or unhealthful ef- fects. Often these undesirable effects of food additives are due to their excessive or acci-