Comparative analyses of phenolic compounds and antioxidant properties of Chinese jujube as affected by geographical region and drying methods (Puff-drying and convective hot air-drying systems).

This work was aimed to investigate the effect of geographical regions and drying methods on phenolics, flavonoids, antioxidant properties, sugars, and acid content of Chinese jujube. The results revealed significant differences in the antioxidant properties and phenolics content of jujube as affected by geographical origin (Hebei, Shandong, Shanxi, Xinjiang, and Henan province) and drying method (puff-drying and convective hot air-drying). The highest concentrations of DPPH (90.01 ± 0.48% DW), FRAP (0.76 ± 0.05 mM TEAC/g DW), TAC (187.16 ± 2.66 mg AEAC /100 g DW), TFC (3.03 ± 0.09 g REAC /100 g DW), TA (1.15 ± 1.10 g CA /100 g DW) and TS (75.10 ± 1.35 g GE /100 g DW) were recorded in the puff dried jujube samples from Xinjiang province. However, samples from Hebei had highest concentration of TPC (2.82 ± 0.13 g GAAC /100 g DW), TANC (46.47 ± 1.64 mg anthocyanin /100 g DW) and TCC (4.27 ± 0.88 mg β-carotene /g DW), while most ABTS (54.45 ± 0.72 µM TEAC/g DW) was recorded in the jujube samples from Henan. Likewise, jujube from Shandong demonstrated highest ferrous chelating activity (89.17 ± 0.52% DW). Similarly, puff dried jujube from Xinjiang had the highest concentration of gallic acid (29.52 ± 0.15 µg/g DW), phloridzin (16.73 ± 0.45 µg/g DW) and cianidanol (60.87 ± 0.71 µg/g DW), whereas, higher concentrations of L-epicatechin (143.59 ± 0.69 µg/g DW) and rutin (10.94 ± 0.78 µg/g DW) were recorded in Hebei, and caffeic acid (66.21 ± 0.88 µg/g DW) in Shanxi province. Conclusively, the bioactive profile of Chinese jujube varies depending upon their geographical origin or drying method used, with puff-drying being a better option to retain the bioactivity. [ABSTRACT FROM AUTHOR]