Thiobarbituric acid reactive substances secondary oxidation products

Other indices measure a secondary stage of oxidation, such as the anisidine value (ANV), pointing to formation of carbonyl compounds, capable of undergoing condensation reactions with p-anisidine, and the thiobarbituric acid reactive substance (TBARS) pointing to the presence of malondialdehyde (MDA) in particular. In biological systems, TBARS is of widespread use as a measure for the extent of oxidation damage. Another test for stability of oils to oxidation is based on the development of acidity as secondary product, for example, standards using the Rancimat equipment or a similar setup. 

Secondary oxidation products oxidation indices, 656, 665-72 acid value, 672 anisidine value, 656, 666 carbonyl compounds, 656, 669-71 conjugated dienes value, 671-2 thiobarbituric acid reactive substances, 656, 666-9... 

Shelf Storage Test The test material is stored under similar conditions as in retail and is evaluated for the effectiveness of antioxidants in prolonging the premium quality of the product. Periodic evaluation of the hpid oxidation products (primary or secondary) by chemical tests (e.g., peroxide value, conjugated diene value, 2-thiobarbituric acid reactive substances, hexanal content) or sensory evaluation will be used to find out the onset of oxidation. The main drawback of this kind of evaluation is the time taken therefore, rapid evaluation or accelerated methods are often preferred (19, 51). 

This assay is basically used to appoint the lipid oxidation. It is an older test for receiving the oxidation status of fats spectrophotometricaUy. Thereby the aldehydes, which are generated by the autoxi-dation of unsaturated fatty acids, are converted into red or yellow colorimeters with TEA. Eut it is also used for the determination of the potency of antioxidants with thiobarbituric acid reactive substances (TEARS). Thereby the antioxidant activity is measmed by the inhibition of the lipid oxidation. It concerns the spectrophotometric detection of malonic aldehyde, one of the secondary lipid peroxidation products, which generates a pink pigment with TEA (Ruberto et al., 2000 Varda-Unlii etal.,2003). 

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