Natural and Synthetic Antioxidants

Antioxidants are substances that can delay or prevent the occurrence of antioxidative reactions of free radicals in lipid oxidation. (Kochhar and Rossell, 1990)

Antioxidants are classified into 2 types:

1. Natural Antioxidants

Natural Antioxidants are classified into antioxidant enzymes and vitamins. Antioxidant enzyme produced by the body in the form of superoxide dismutase (SOD), glutathione peroxidase, and catalase.

Antioxidant vitamins in getting the food they have in the form of fruits and vegetables. Antioxidant vitamins, namely alpha tocopherol (vitamin E), beta carotene (vitamin A), and ascorbic acid (vitamin C).

Fruits that contain antioxidants such as the apples, tomatoes, oranges, grapes, blueberries, blackberries, strawberries, and cherry.

Vegetables that contain antioxidants such as namely broccoli, cabbage, Brussel sprouts, cauliflower, sprouts, garlic, and potatoes.

Research published in the International Journal of Food Science and Technology says that natural antioxidants can be derived from olive leaf extract rich in polyphenols. The study reported that olive polyphenol concentration of 400 ppm produced the same antioxidant activity with 200 ppm BHT, while 800 ppm of olive polyphenols significantly higher antioxidant activity than synthetic antioxidants.

In a study published in the journal 'Experimental Biology and Medicine' is, Gershwin and his colleagues took an apple extracts taken at random from different varieties of apples, then enter into endothelial cells in blood vessels and add the extract on cell tumor necrosis factor (TNF ), a cell that can increase inflammation and have the possibility of killing body cells. And The apple extract was able to protect healthy cells from the cell that already contains TNF.

According to Pratt (1992), a natural antioxidant in food antioxidant compounds derived from existing components from one or two foods, antioxidant compounds derived from reactions during processing, and antioxidant compounds isolated from natural sources and added as food additives .

2. Synthetic Antioxidants

Among several examples of synthetic antioxidants permitted for food, there are five antioxidants that extends its use and spread around the world, namely Anisol Butyl Hydroxy (BHA), Butyl Hydroxy toluene (BHT), propyl gallate, tert-butyl Hidoksi Quinon (TBHQ) and tocopherols.

BHA has the ability of antioxidants (carry through, the ability of antioxidants good views of resistance to the stages of management and stability in the final product) is good on animal fats in baked food systems, but relatively not effective on plant oils. BHA is fat soluble and water insoluble, solid white and is sold in tablets or flakes, are volatile, so useful for adding to the packing material (Buck, 1991; Coppen, 1983).

According to Sherwin (1990), synthetic antioxidants BHA BHT has a similar nature, will give a synergistic effect when used together with BHA, a white crystalline solid and is widely used because it is relatively inexpensive. Propyl error has the characteristic sensitive to heat, decomposes at melting point of 148 0C, to form a color complex with metal ions, so that low antioxidant capacity. In addition, propyl error has shaped the nature of a white crystalline solid, a little fat soluble but water soluble, and provide a synergistic effect with BHA and BHT (Buck, 1991).

TBHQ is known as the most effective antioxidant for fats and oils, especially plant oils because it has a good ability of antioxidants in frying pan, but low in combustion. When TBHQ is recommended by the ability of antioxidants BHA good at roasting will give wider use. TBHQ is known a powdery white to light brown, has a sufficient solubility in fats and oils, do not form a color complex with Fe and Cu but it can turn pink in the presence of bases (Buck, 1991).

Tocopherol is a natural antioxidant that can be found in almost every plant oils, but now can be produced chemically. Tocopherol has a characteristic bright yellow, quite soluble in lipids because of the long C chain. Effect of complete nutrition of tocopherol is not known, but α-tocopherol is known as a source of vitamin E. In living tissue, the antioxidant activity of α-tocopherol tended> β-> γ-> δ-tocopherol, but in food activities inverted δ-tocopherol> γ-> β-> α-tocopherol (Belitz and Grosch, 1987). According to Sherwin (1990), that order sometimes varies depending on the substrate and other conditions such as temperature.