2000/07/01 by Jer‐Hour Liang, Chih‐Cheng Lin
Chemistry · Biochemistry, Genetics and Molecular Biology · #Edible Oils Quality and Analysis #Dye analysis and toxicity #Advanced Glycation End Products research
paper · doi:10.1007/s11746-000-0114-5
Abstract Changes in fluorescence and oxidation indices of soybean flour were studied during storage at 37, 50, and 60°C. The peroxide value and 2‐thiobarbituric acid value did not increase in proportion to the extent of oxidation. The front‐surface fluorescence of oxidized soybean flour had an excitation maximum around 350 nm and an emission maximum between 420 and 430 nm. The fluorescent compounds were soluble in the organic phase of chloroform/methanol (2∶1, vol/vol) after addition of water, and the solution showed excitation and emission maxima around 360 and 440 nm, respectively. The fluorescent compounds might have been produced from interactions of oxidizing soybean oil with other constituents of soybean flour. The fluorescence intensity in the organic phase increased steadily throughout the storage period. Fluorescence kinetics of soybean flour oxidation showed a zero‐order increase, and the rate followed an Arrhenius relationship with an activation energy of 47.8 kJ/mol. These results suggest that analysis of fluorescence intensity in the organic phase is a useful indicator for determination of the oxidative deterioration of soybean flour.