Preservatives Used in Foods
People are more aware of the preservatives used in the foods they are consuming. In the past, basic food preservation consisted of techniques like boiling, pasteurizing, pickling, dehydrating and refrigerating. Salt and sugar were also commonly used as methods of preserving food. Eventually, the traditional methods were supplemented, and in some cases, replaced by newer techniques, such as radiation, vacuum packaging. Today, much of the food preservation process is carried out by the use of additives in foods.
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Significance
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Food preservation is primarily used to deter the spoilage of products during processing and transporting to the consumer markets. Food typically spoils due to bacteria, air, mold, yeast and fungi.
Preservatives were also commonly used to maintain the coloration of fresh fruits and vegetables, or to manage food contamination, which often led to food poisoning, such as botulism. Most foodstuff, with the possible exception of foods cultivated in personal gardens, may contain some form of preservatives. There are basically three categories of preservatives: anti-oxidants, anti-microbials and metal chelators.
Anti-Oxidants
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Anti-oxidants are used as a source of preservatives in food because they have the ability to slow down the air oxidation of lipids and unsaturated fats. This process, which is called auto-oxidation, occurs when air, moisture and other substances react with the fats and lipids to change the chemical composition. This is what leads to the offensive taste and odors. Some commonly use anti-oxidant preservatives used in foods are: propyl gallate, butylated hydroxyanisole, butylated hydroxytoluene and tert-butylhydroquinone.
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Anti-Microbials
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A type of food preservative that is very popular is anti-microbials. They slow the growth of mold, bacteria and yeast. Propionate acids are naturally produced in foods, such as apples, strawberries cheese and grains. It is commonly used in baked goods because of its anti-microbials properties that prevent mold. Sulfur dioxide is another anti-microbial preservative; it, and similar compounds called sulphites, are effective against preventing mold, yeast and bacteria. Many packaged meats contain nitrates.
Metal Chelators
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Many foods contain enzymes that continue to work after the product is harvested. For example, potatoes and apples have an enzyme known as phenolase. Phenolase immediately goes into action when a potato is taken out of the ground or an apple is cut; it causes the food to turn brown. Ascorbic acid and citric acid are metal chelators that hamper the activity of phenolase.
Product Label
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The Food and Drug Administration (FDA) has the regulatory responsibility for assessing and evaluating food preservatives and other ingredients added to food. They look at factors, such as the substance properties, the average amount ingested, health-related concerns and other safety issues. The FDA requires manufacturers to list all ingredients, including preservatives used in foods, on the package label. The ingredients are typically listed in the order of the ingredients with the highest amount listed first and the other constituents in descending order.
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