Effects of sulfur dioxide concentration on organic acids and beta-carotene in dried apricots during storage

The effects of various sulfur dioxide (SO2) concentrations (0, 451, 832, 1594, 2112 and 3241 mg/kg) on the profiles and contents of organic acids (OAs) and beta-carotene in sulfured dried apricots (SDAs) were investigated during storage at 4, 20 and 30 degrees C for 379 days. In all samples, four OAs [malic acid (MA), citric acid (CA), succinic acid (SA) and oxalic acid (OXA)] were identified. SA (13.9-31.8 g/kg dw) was the major OA in SDAs containing SO2 at lower than 1594 mg SO2/kg, while MA (11.7-11.7 g/kg dw) was the major OA in SDAs containing SO2 at higher than 1594 mg SO2/kg. As SO2 concentration increased, CA and OXA contents increased whereas MA contents decreased. Moreover, the highest stabilities of beta-carotene, MA and SO2 were determined in SDAs containing 1594 mg SO2/kg at 4 degrees C. Therefore, we suggest using 1594 mg SO2/kg and storing SDAs at 4 degrees C to protect OAs and b-carotene. (C) 2016 Elsevier Ltd. All rights reserved.