Citric synergistic effect with antioxidant

Sequestrants form complexes with metal ions, which accelerate oxidative degradation, and show synergistic effects with the a.m. antioxidants. - Phytic acid, calcium gluconate (- gluconic acid), - lactic acid and lactates, - tartaric acid and tartrates, - citric acid and citrates and - lecithin are such RR-based products. 

Chelators. The type of positive synergistic effects described above are not to be confused with synergism as referred to when an antioxidant is added with an add chelator, such as citric acid. Acid chelators, or sequestrants, are referred... 

Butylatedhydroxyamsole (BHA) was first used in food products in 1940. This continues as one of the commonly used antioxidants, sometimes in combination with butylated hydroxytoluene (BHT), propyl gallate, citric, or phosphoric acids, to obtain a synergistic effect. In foodcontact surfaces. BHT has been used by itself or in combination with thiodipropionates and/or phosphoric acids, to obtain a synergistic effect. Well over 50 million of antioxidants are produced per year commercially in the United Slates alone. 

Muscle tissues contain a multi-component antioxidant system consisting of lipid-soluble compounds (a-tocopherol, ubiquinone), water-soluble compounds (ascorbate, histidine-dipeptides) and enzymes (superoxide dismutase, catalase, glutathione peroxidase). Lipid oxidation in meats can be effectively controlled by the use of various phenolic compounds derived from spice extracts, by vitamin E supplementation of animal diets, and by processing of cured meat with sodium nitrite. Various natural antioxidant formulations containing mixtures of tocopherols, ascorbyl palmitate and citric acid show synergistic effects in stabilizing cooked and frozen meat. Synthetic antioxidants, BHA, TBHQ, propyl gallate (see Chapter 9) and combinations with citric acid, ascorbic acid or phosphates are also effective formulations used to retard lipid oxidation in... 

Hras AR, Hadolin M, Knez Z, Bauman D (2000) Comparison of antioxidative and synergistic effects of rosemary extract with a-tocopherol, ascorbyl palmitate and citric acid in sunflower oil. Food Chem 71 229... 

Ascorbic acid also forms soluble chelate complexes with iron (142—145). It seems ascorbic acid has no effect on high iron levels found in people with iron overload (146). It is well known, in fact, that ascorbic acid in the presence of iron can exhibit either prooxidant or antioxidant effects, depending on the concentration used (147). The combination of citric acid and ascorbic acid may enhance the iron load in aging populations. Iron overload may be the most important common etiologic factor in the development of heart disease, cancer, diabetes, osteoporosis, arthritis, and possibly other disorders. The synergistic combination of citric acid and ascorbic acid needs further study, particularly because the iron overload produced may be correctable (147). 

In addition to the phenolic antioxidants, there are a large number of compounds of widely different chemical composition which have no protective effect when added to pure triglycerides but which enhance the keeping qualities of animal fats if added along with a phenolic antioxidant and which are therefore termed synergistic antioxidants. Members of this group which have been approved as additives to lard are citric acid... 

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