Changes of Some Chemical Substances and Antioxidant Capacity of Mandarin Orange Segments during Can Processing

Abstract

Abstract Changes of ascorbic acid (AA), flavanone glycosides (FGs), phenolic acids and antioxidant capacity which was expressed as ascorbic acid equivalent capacity (AEAC) of total antioxidant capacity (TAC) determined by ferric reducing antioxidant power (FRAP) assay and radical scavenging capacity (RSC) determined by 2, 2-diphenyl-1- picrylhydrazyl (DPPH) assay, of mandarin orange segments during can processing were investigated. The effects of four key processing procedures were studied, namely blanching, HCl, alkaline and canning treatment. As a result, after canning, the total FGs content of mandarin segments decreased from 502.39 mg/kg to 254.27 mg/kg, and the total phenolic acids from 57.51 mg/kg to 44.20 mg/kg. The similar decreasing tendency was also true to the AA content of mandarin segments (from 251.87 mg/kg to 186.98 mg/kg), TAC (from 664.48 mg/kg to 391.95 mg/kg), and inhibition of DPPH radical (from 34.85% to 27.31%). To be concluded, small proportions of phenolic acids and AA were lost, and the loss of FGs and TAC was about fifty percent. However, in view of the considerable part of phenolic compounds and AA existing in the syrup portion; the loss was not as large as that. Therefore, we suggested that the majority of AA, phenolic compounds (FGs and phenolic acids) and antioxidant capacity of mandarin segments were retained after can processing, and mandarin cans could serve as a substitute when fresh mandarin fruits are not available.