Organic acids as pro-oxidants

The use of sulfite, one of the very first preservatives, has been greatly reduced because of reports of adverse effects on human health, especially in steroid-dependent asthmatics. It has been replaced in food preservation by the use of organic acids. In various studies, however, it has been found that preservatives are also acting as pro-oxidants and can even be mutagenic toward the mitochondrial genome of yeasts in aerobic environments. The potential for weak organic acid food preservatives to act as pro-oxidants in humans should receive much attention if only to reassure the public of the complete safety of these compounds (Piper, 1999). 

Ascorbic acid acts as both an antioxidant and a pro-oxidant. Appropriate levels for preventing muscle discoloration are, therefore, dependent on a number of factors, such as the presence and concentration of metals within a food (Mancini et al., 2007). Ascorbic acid s pro-oxidant action could also be attributed to the production of ferrous heme proteins, which may be more reactive and more oxidative than ferric derivatives (Yamamoto, Takahashi, and Niki, 1987). The addition of citric acid as chelator may improve the efficacy of ascorbic acid in muscle food (Mancini et al., 2007). 

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