Comprehensive evaluation of natural antioxidants and antioxidant potentials in Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou fruits based on geographical origin by TOPSIS method

Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method was used to comprehensively evaluate total natural antioxidants and antioxidant activities in Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou fruits based on geographical origin. Correlations between natural antioxidants, antioxidant activities and geographical conditions were investigated. TOPSIS evaluation showed that the fruits from Ningxia possess the largest amount of natural antioxidants and antioxidant activities among other samples. Correlation analyses indicated that both altitude and annual precipitation exert profound effects on natural antioxidant levels. Moreover, the fruits exhibited significant DNA damage protection activity and in vitro antiradical potentials. In particular, the fruits from Ningxia, Gansu and Shaanbei which were grown in the semi-arid regions of loess plateaus showed fairly higher antioxidant activities. To a certain degree, this study concludes that the fruits in arid harsh and high-altitude areas can accumulate higher levels of natural antioxidants and display stronger antioxidant activities.