Inhibited Oxidation of Lipids I: Complex Estimation and Comparison of the Antioxidative Properties of Some Natural and Synthetic Antioxidants

✍ Scribed by Yanishlieva, Nedjalka V. L. ;Marinova, Emma M.

• Publisher: John Wiley and Sons
• Year: 1992
• Weight: 506 KB
• Volume: 94
• Category: Article
• ISSN: 0931-5985
• DOI: 10.1002/lipi.19920941004

✦ Synopsis

i n o v a l

The activity A of antioxidants, representing a ratio between the stabilization factor F and the decrease in oxidation rate after the introduction of an inhibitor DOR ( A = F/DOR) is proposed for a complex estimation of the effect of antioxidants. The specific changes in F, DOR and A arc discussed in association with the participation of the inhibitor molecule and thc radical formed from it in the different reactions of initiation and piopagation of the chains. Several types of antioxidants (a-tocopherol, ferulic acid, BHT and BHA) in concentrations ranging from 0.02 -0.20 wt% are investigated during the oxidation of lard at 100°C. It is established that at concentrations of 0.02-0.05 wt% the antioxidative activity increases in the sequence fcrulic acid < BHT < BHA <a-tocopherol. At high concentrations (above 0.10 wt%) the activity incrcase follows the sequence a-tocopherol c BHT < BHA < ferulic acid. Enhancement of thc antioxidant concentration above 0.02 wt% is expedient only in the case of ferulic acid. The molecules of atocopherol, BHA and BHT participatc not only in chain tcrmination but also in first order ratc side reactions with respect to the inhibitor, which explains the decrease in their efficiency with rising conceotration. The molecule of ferulic acid does not participate in side reactions. Thc aroxyl radical formcd from BHT does not participate in chain propagation, whereas the radicals of BHA and ferulic acid take part in such rcactions. The aroxyl radical of a-tocopherol joins in more than one side reactions.

Fat Sci. Techno1

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