## Abstract A model system was used to study the pattern of rancidity in linoleic acid and corn oil using the TBA method. It was shown that malonaldehyde is not a stable end product of rancidity and therefore, the TBA test is not a reliable means of quantitative feasurement of degree of rancidity i
Modified determination of 2-thiobarbituric acid value in fats and oils
✍ Scribed by Pokorný, J. ;Valentová, H. ;Davídek, J.
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 410 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0027-769X
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✦ Synopsis
Several methods for the determination of TBA-value were compared with a new direct modification (omitting the previous distillation), using I-butanol as the sole solvent. The absorbance is measured at 530 nm after heating to 95 "C for 120 min, and cooling. The effect of variables was tested by the YOUDENS ruggedness test (reaction time, temperature, cooling, concentration of sample, thiobarbituric acid, water, heavy metals, antioxidants, chelating agents, bubbling with oxygen or nitrogen). The LAMBERT-BEERS law is valid in the absorbance range between 0.05 and 0.8. The repeatability is better than that of the DZIKOWSKIS procedure and comparable with those of more complicated distillation methods. The standard deviation is in a linear relation with the absorbance (range 0.1-1.0). The method was found satisfactory for evaluating lard, cooking fat, soybean, sunflower, and rapeseed oils in the stage of beginning rancidity.
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