Fermentation‐Induced Modulation of Polyphenolic Contents and Medicinal Activities in <i>Annona squamosa</i> Seeds

ABSTRACT Fermentation is critical in the alteration of biochemical components in seeds, plants, and foods. Polyphenol is contained in the seed of Annona squamosa . In the study, the medicinal activities of polyphenols from fermented and unfermented seeds of A. squamosa were compared. The extraction of the polyphenols was done with the aid of a Soxhlet extractor. The phytochemicals were determined by standard techniques, and the polyphenols in the samples were identified using GC‐MS. The α‐amylase and α‐glucosidase assays were used to measure the antidiabetic activity. Xanthine oxidase inhibition and lipoxygenases were used to carry out the anti‐inflammatory activities. DPPH (2,2‐diphenyl‐1‐picrylhydrazyl), lipid peroxidation, ABTS (2,2‐azobis‐3‐ethylbenzthiazoline‐6‐sulphonic acid), and nitric oxide tests were used to assess antioxidant activity. The major phenolic components of the fermented seed polyphenols (FSP) and the unfermented seed polyphenols (USP) were found to be phytol (17.69%) and linoleic acid (28.46%), respectively. The phytochemical analysis showed that the FSP contained higher phenolic content, flavonoids, flavonols, proanthocyanidin, and tannin. The α‐amylase and α‐glucosidase assays showed FSP with the lowest IC 50 values. The FSP recorded the highest anti‐inflammatory activity with the least IC 50 observed for lipoxygenase inhibition and xanthine oxidase inhibition. The FSP with respect to DPPH and ABTS, with IC 50 of 713.51 μg/mL and 1019.32 μg/mL, recorded a higher antioxidant potential compared to USP. This was contrary to what was observed for the nitric oxide and lipid peroxidation assays, where the USP had a higher inhibition activity than the FSP. The result showed that the polyphenols from the fermented seeds of A. squamosa had a better medicinal activity than those of the unfermented seeds.