Higher Correlation with Sensory Evaluation of Oxidative Rancidity by Modified TBA Test
✍ Scribed by Marcuse, R. ;Pokorný, J.
- Publisher
- John Wiley and Sons
- Year
- 1994
- Weight
- 228 KB
- Volume
- 96
- Category
- Article
- ISSN
- 0931-5985
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✦ Synopsis
Abstract
When carrying out the TBA reaction test with oxidized lipids in the conventional way, a red colour with maximum absorption at 530 nm is measured as degree of rancidity. This colour corresponds mainly to alkadienals formed as products of oxidation. Before the formation of this red colour, a transient yellow colour with maximum absorption at 450 nm is formed, which corresponds to both alkanals, alkenals and alkadienals, consequently having a “broader” and also higher sensitivity. By modifying the conditions of the reaction (heating at a lower temperature, e. g. 2 hours at 50°C) the yellow colour becomes stable enough to be measured. The paper shows that the greater sensitivity of measuring the yellow colour absorption corresponds to higher correlation with sensory evaluation, particularly in the case of low unsaturated samples.