Modified determination of 2‐thiobarbituric acid value in fats and oils

Abstract

Several methods for the determination of TBA-value were compared with a new direct modification (omitting the previous distillation), using 1-butanol as the sole solvent. The absorbance is measured at 530 nm after heating to 95 degrees 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.

Methods for Evaluation of the Oxidative Stability of Lipid-Containing Foods.

“…Modifications of the original TBA test have been reported by Marcuse & Johansson (1973), Ke & Woyewoda (1979), Robles-Martinez et a/ (1982), Pokorny et al (1985), Shahidi et al ( 1987), Tomas & Funes ( 1987) and Schmedes & Holmer ( 1989). However, it has been suggested TBARS provide an excellent means for evaluating the relative oxidative status of a system as affected by storage or processing variables (Gray & Pearson, 1987 (Gray, 1978) and canola (Hawrysh, 1990).…”

Effect of lipoxygenases on the lipid oxidation during the storage of poppyseed (Papaver somniferum L.)

“…Details were reported earlier [ll]. The peroxide value was determined iodometrically with spectrophotometric measurement of liberated iodine [12], and the thiobarbituric acid value was determined in the acetone extract with use of I-butanolic solution of the reagent [13]. Total oxidation products were determined by reversed-phase HPLC [14].…”

Lipid Oxidation/Stability

“…Due to uncertainty concerning the exact identity of compounds that can react with TBA, the ambiguous term TBARS is now commonly used in lieu of TBA number or value (Ke et al, 1984;Gray and Pearson, 1987;GuillCn-Sans and Guzmin-Chozas, 1998 (Marcuse and Johansson, 1973;Ke and Woyewoda, 1979;Robles-Martinez et al, 1982;Pokorny et al, 1985;Tomis and Funes, 1987;Schmedes and HQlmer, 1989), but this raises a host of new problems. Sample preparation, types of acidulants and their concentrations in the reaction mixture, pH of the reaction mixture, composition of the TBA reagent, length of the TBA reaction, and possible use of antioxidants and chelators in the systems are among the factors that may influence results reported by researchers from various laboratories.…”