Effect of ripening stage and extraction technique on polyphenolic profile and antioxidant activity of Ziziphus mauritiana

Ziziphus mauritiana Lam. (family: Rhamnaceae) is a wild edible fruit known for its rich nutritional and pharmaceutical properties. This study evaluates how different ripening stages and extraction methods affect its phytochemicals, nutritional value, and antioxidant potential. Amongst the total phenolic content (TPC), total tannin content (TTC), total flavonoid content (TFC), total protein content (TP), and antioxidant activity [ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH)] were observed significantly ( p < 0.05) higher in the initial ripening stages and decreased with fruit ripening. Whereas, the total anthocyanin content (TAC) and total carbohydrate content (TC) increased with fruit ripening and recorded maximum in the fully ripened stage (S6). Among the tested extraction techniques, conventional heat-assisted water bath extraction yielded significantly ( p < 0.05) higher concentrations of phytochemicals [TPC (40.967 ± 0.224 mg GAE/g FW), TFC (4.775 ± 0.016 mg QE/g FW), TTC (4.781 ± 0.228 mg TAE/g FW)] and antioxidant activities [DPPH (2.349 ± 0.004 mg AAE/g FW), FRAP (9.035 ± 0.302 mg AAE/g FW), and 2,2 azinobis, 3-ethylbenzothiazoline-6-sulfonic acid (ABTS:5.615 ± 0.101 mg AAE/g FW)]. High-Performance Liquid Chromatography with Photodiode Array detectors (HPLC-PDA) analysis identified and quantified 4 bioactive polyphenolic compounds (viz., ascorbic acid, chlorogenic acid, gallic acid, and vanillic acid) across different ripening stages of Z. mauritiana and 6 bioactive compounds (viz., gallic acid, vanillic acid, ascorbic acid, chlorogenic acid, p-hydroxybenzoic acid, and catechin hydrate) across tested extraction techniques. Findings suggest that the initial ripening stage (S1) of Z. mauritiana is rich in phytochemicals, antioxidants, and polyphenols, and for their optimum harnessing, the heat-assisted water bath extraction technique is the best-performing under tested settings.