Main nutrients, phenolics, antioxidant activity, DNA damage protective effect and microstructure of Sphallerocarpus gracilis root at different harvest time

Sphallerocarpus gracilis roots harvested at two different times (T1: 12-10-2009 and T2: 15-04-2010) were analysed for their main nutrients, phenolics, antioxidant activity, DNA damage protective effect and microstructure. Results revealed that higher amounts of starch were detected in T1 S. gracilis root, whereas higher levels of reducing sugar, protein, amino acids and phenolic compounds were determined in T2 S. gracilis root. The antioxidant activity was assessed by DPPH, FRAP and TEAC assay and T2 S. gracilis root was found to possess higher antioxidant activity. Also, results of the correlation analysis indicated that caffeic, p-coumaric and gallic acids contributed substantially to the antioxidant property and there was significant correlation between DPPH radicals scavenging capacity and FRAP and TEAC. The highest and lowest DNA damage protective effects were found of free phenolic extracts from T2 and T1 S. gracilis roots, respectively. The microstructure of S. gracilis root varied greatly with the harvest time.