Deterioration of Fats and Oils and Its Preventive Countermeasures
1989 Volume 38 Issue 7 Pages 545-552
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1989 Volume 38 Issue 7 Pages 545-552
A review on 119 original papers for the Japan Oil Chemist's Society Award is presented.
1) After heating the decrease of the oxidative stability by tocopherol (Toc) degradation was larger for olive, coconut and hardened oils than for soybean, corn, cottonseed, and rapeseed oils. Decomposition of Toc in oils was apparently promoted by the oxidative products (especially oxidized fatty acids: fatty substances insoluble in petroleum ether) and free fatty acids. The preventive effects of additive on the thermal decomposition of Toc in oils were in the order of gallic and thiodipropionic acids>cystine>homogentisic acid>tryptophan>soya lecithin>catechins.
2) Histidine (His) and Cu (II)-His complex inhibited the photosensitized of unsaturated fatty acid by quenching 1O2, and O2-, respectively. Gly-Gly-His inhibited both the outoxidation and the photosensitized oxidation in the presence of copper (II) ion.
3) Antioxidative activity of metabolic products of several amino acids was investigated. In the metabolites of tryptophan, proline, and phenylalanine, the 3-hydroxyanthranilic acid, 5-hydroxyproline and homogentisic acid showed great antioxidative activity on the autoxidation of lard, respectively.
4) The greatest anitioxidative activity was recognized with methanol extracted fraction of the smoke or tea and tea-grounds, and by the analysis, naphtol, isoamyl gallate and hydroquinone were detected in smoke. Epigallocatechin in tea showed the strongest antioxidative effect for oils.
5) Antioxidant was adsorbed on paper, and the antioxidant paper was packed with various foods in bag. Oxidative stability of Foods was considerably improved with indirect method of antioxidant NDGA and BHA.
6) BHA, NDGA, isoamyl gallate and hydroquinone showed a potent antiseptic and antimold action on the microbe or mold.
7) The decomposition of amino acids, vitamins, and chlorophyll was apparently promoted by oxidative products (oxidized fatty acids, peroxide and malonaldehyde etc.) of oil.
8) The rats fed oxidized oil showed growth depression, whereas better growth was observed those fed same oil with Toc, oryzanol, pyridoxine, and water extractum of animal liver or garlic, respectively.
