Variations of Antioxidant Properties and Enzymes Activities during the Whole Fruit Fermentation of Two Kiwifruit (Actinidia chinenesis Planch.)

ABSTRACT In this study, antioxidant properties and enzymatic activities during fermentation of Kiwifruit from two Actinidia genotypes were evaluated. The samples were evaluated for solid content (SSC), total phenols, superoxide dismutase (SOD) and protease. Antioxidant capacity was determined using four assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azimo-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), hydroxyl radical (HR) scavenging rate and superoxide anion radical (SAR) scavenging rate. In the process of fermentation, the antioxidant and enzyme activities of artificial fermentation kiwifruit products were significantly higher than those of natural fermentation (p < .05). At the end of fermentation, the contents of total phenols and SSC in the fermented products of Hongyang kiwi fermentation (HKF) group and Cuiyu kiwi fermentation (CKF) group were significantly decreased, while the antioxidant properties of DPPH, ABTS, HR and SAR were significantly increased compared with the fresh kiwi (p < .05). In addition, the content of protease and superoxide dismutase was also increased. It was also found that the antioxidant properties and the enzyme activities in the HKF group were higher than those in the CKF group. ABTS and SOD activities were more obvious, which were 1.42 times and 2.22 times of the CKF, respectively. HKF group showed better nutritional properties and biological activities.