Amino acid profile and content of dried apricots containing SO2 at different concentrations during storage

The profile and content of amino acid in dried apricots containing various SO2 concentrations (0, 451, 832, 2,112 and 3,241 mg SO2/kg) were determined during storage at 4, 20 and 30 degrees C for 379 days. Major amino acid was aspartic acid (2,872-5,692 g/kg dw), followed by glutamic acid (695-989 g/kg dw), glycine (90-144 g/kg dw), alanine (16-35 g/kg dw) and valine (17-29 g/kg dw). Good correlation (r=0.712) was found between SO2 concentration and aspartic acid content. SO2 led to the reduction in the synthesis of glutamic acid, glycine, alanine and valine before storage. The highest stabilities of amino acids during storage were found in the samples containing 451 mg SO2/kg. Reduction rates for aspartic and glutamic acids at 30 degrees C were generally slower than those at 20 degrees C. As a result of this finding, the main reason for the reductions in aspartic and glutamic acids in dried apricots could not be due to Maillard reaction. Thus, the food additive to be used in place of SO2 to prevent browning in dried apricots must slow down the synthesis of glycine, alanine and valine.