The Effectiveness of Antioxidants

The Effectiveness of Antioxidants
Some antioxidants lose their effectiveness when they combine with oxygen; therefore, there is no advantages to using this type of antioxidant unless the food is enclosed in a system from oxygen or air can be excluded. In the use of antioxidants, it should be kept in mind that other precautions are necessary to minimize oxidation since heat, light, and metals are prooxidants, that is, their presence favors oxidative reactions.

Many of the antioxidants used in commerce occur naturally in foods (e.g., vitamin C, citric acid, amines, and certain phenolics compounds). However, the amines and the phenolics compounds can be toxic to human in low concentrations; therefore, they and the synthetic antioxidants require strict regulations of their use in foods.

It should be pointed that the potency of the naturally occurring antioxidants is not as great as that of the commonly used synthetic antioxidants. The antioxidants that are considered to be the most effective and therefore are most widely used are butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and propylgallate.

These are usually used in formulations that contain combinations of two or all three of them, and often in combination with even fourth component, very often citric acid. The main purpose in adding citric acid is for its action as a chelator.

Fats and shortening, especially those used in bakery goods and fried foods, are subject to oxidation and the development of rancidity after cooking. To prevent this, chemical antioxidants in concentrations up to 0.02% of the fat components may be added.
The Effectiveness of Antioxidants

Antioxidants as food additive

Antioxidants as food additive
Antioxidants are food additives used, since about 1947, to stabilize foods that by their composition would otherwise undergo significant loss in quality in the presence of oxygen. Oxidative quality changes in foods include the development of rancidity from oxidation of unsaturated fats resulting in off-odors and off-flavors and discoloration from oxidation of pigments or other components of the food.

Although it would seem relatively simple to prevent oxidation of foods by proper packaging and precaution during handling, the facts are that oxygen is difficult to exclude from food systems, especially since it is often closely associated with the food and that only minute amounts of oxygen are sufficient to degrade the food.

There are a large number of antioxidants, and although they may function in different ways, the net effect of each is to prevent, delay, or minimize the oxidation of foods to which they are added. One other ways by which some antioxidants function involves their combination with oxygen.

Others prevent oxygen from reacting with components of the food. When only a limited amount of oxygen is present, as in a hermetically sealed container, it is possible for some antioxidants to use up all of the available free oxygen, because they have a relatively great affinity for it.
Antioxidants as food additive