A new method for estimating quality deterioration of agricultural products

A new method has been developed to measure the amount of 1,3-diethyl-2-thiobarbituric acid (DETBA)-malondialdehyde (MDA) adduct as an index of lipid peroxidation. The DETBA-MDA adduct is extracted with ethyl acetate and the amount is measured by spectrofluorometry or high-performance liquid chromatography with a fluorescence detector. The DETBA method which is highly sensitive, and specific, is as simple as the traditional colorimetric TEA method, and enables to measure DETBA values from several agricultural products. The use of the DETBA method enabled to discriminate slight differences in garden peas with external deterioration that was hardly recognizable with the naked eye. The increase in the DETBA values during storage of the garden peas was closely related to the change in surface color and the decrease in the contents of both chlorophyll and reduced form of (or total) ascorbic acid contents. Similar observation was also made in sweetpotatoes. These results suggest that the DETBA method is suitable for estimating quality deterioration during the storage of agricultural products.