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 ac etate and the amount is measured by spectrofluorometry or high-perform ance liquid chromatography with a fluorescence detector. The DETBA met hod which is highly sensitive, and specific, is as simple as the tradi tional colorimetric TEA method, and enables to measure DETBA values fr om several agricultural products. The use of the DETBA method enabled to discriminate slight differences in garden peas with external deteri oration that was hardly recognizable with the naked eye. The increase in the DETBA values during storage of the garden peas was closely rela ted to the change in surface color and the decrease in the contents of both chlorophyll and reduced form of (or total) ascorbic acid content s. Similar observation was also made in sweetpotatoes. These results s uggest that the DETBA method is suitable for estimating quality deteri oration during the storage of agricultural products.