Biological systems peroxide value

This method is relatively easy to use for anhydrous systems, but not for emulsions, foods, or biological media where the presence of water is detrimental. The method has been applied for determining antioxidant activity of both individual natural polyphenols and vegetable extracts. Methods based on this one have been used to evaluate the peroxide value in walnuts (Wilson-Kakashita and others 1995), mango seeds (Joseph 1995), almonds (Uthman and others 1998), and coconut cream powder (Yusof and others 2007). 

Peroxide value (POV), 656, 657-64 chromatography, 672 colorimetric determination, 632 mbber and elastomers, 676 Peroxisomes, antioxidant in biological systems, 610, 611 Peroxo complexes... 

Fats with peroxide values of 100 (88) cause no obvious effect when fed to rats. Peroxide values of 800 will cause loss of appetite and decreasing ability to gain weight, while values of 1200 can be quite toxic. Peroxide values in excess of 100 are rarely encountered with good commercial practices (89). Heat-induced cyclization or polymerization of fats results in quite toxic compounds when tested with rats. These materials may affect membrane function (90), liver enlargement (91) and other biological systems(92). 

The thiobarbituric acid (TBA) value test is a popular way of measuring rancidity in certain foods and oxidation products in biological systems. It is based on the formation of a colored complex between two molecules of TBA and one molecule of malonaldehyde resulting from thermal decomposition of polyunsaturated peroxides. This reaction is not specific due to the presence of many TBA-reactive substances (TBARS), such as browning reaction products, protein and sugar decomposition products, amino acids, nucleic acids and nitrite. 

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