Fish 9 Antioxidant Mechanisms

Adsorptive purihcation, in its most general sense, involves the use of adsorbents to remove undesirable constiments and contaminants from fats and oils by adsorptive mechanisms. It must be noted, however, that although different adsorbents do exhibit some degree of selectivity for certain adsorbates (see Section 4.3), none exhibit specific selectivity for a single compound or chemical. Some trace constituents that are desirable (e.g., tocopherols) will also be removed. According to Boki et al. (106), 20-40% of the tocopherols present in most alkali-refined oils are removed by bleaching with acid-activated bleaching clay the exception is soybean oil, which only loses 3-5% (71, 105). Buxton has reported (107) that activated carbon removes antioxidants from fish hver oils and renders the vitamin A in the oil unstable. 

The recent literature indicates that n-3 supplements have shown anti-inflammatory activity against arthritis, lupus, and IgA nephropathy as well as protection against bone loss in both human and animal studies (122). Currently, fish oil intake is no longer an undesirable food supplement. It is available in concentrated form with antioxidants and in various flavors (orange or raspberry). One of the mechanisms by which fish oil exerts its protective action against bone loss is by decreasing urinary calcium loss (179-181). 

Extracts of shrimps and other crustaceans are desirable as taste additives in foods that are to have shellfish character. In addition, a hydrolysate from fish myofibrils has been claimed to have a synergistic effect with antioxidants (Hatate et al., 1990). This has also been reported for a mixture of amino acids from krill (Seher and Lbschner, 1986). In one case the single amino acid, proline, has been used as an antioxidant in fish oil (Revankar, 1974). The precise mechanisms for the antioxidative or synergistic actions are not known. 

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