Loss of sulfur dioxide and changes in some chemical properties of Malatya apricots (Prunus armeniaca L.) during sulfuring and drying

BACKGROUND: This study was conducted to determine the differences in some analytical properties of four apricot cultivars and to determine the changes in these analytical properties during sulfuring and sun-drying. RESULTS: There were significant differences in the contents of polyphenols, carotenoids and organic acids (OA) as well as antioxidant activities (AOAs) of the cultivars (P < 0.05). After sulfuring and drying, considerable reductions were detected in the contents of total polyphenols (TPCs, 11-26%), OAs (4-32%) and beta-carotene (6-21%), and AOAs (2-21%) of the samples. Sun-drying resulted in 71-83% decreases in sulfur dioxide (SO2) contents of sulfured-dried apricots (SDAs) in comparison with apricots immediately after sulfuring. As the TPCs increased, the SO2 absorption by the samples also increased. In contrast, the OA contents had no effect on SO2 absorption, but an increase in OA content resulted in an increase in the browning values of the SDAs. As expected, increases in contents of ferulic acid (r = 0.932), chlorogenic acid (r = 0.850), epicatechin (r = 0.804) and quercetin (r = 0.750) led to an increase in browning values of the SDAs. CONCLUSION: There were significant effects of cultivar and processing on the physico-chemical properties investigated in the study, and with the absorption of SO2 and the formation of a brown colour in the samples. (C) 2014 Society of Chemical Industry