Bioactive Components, Nutritional Properties, and Antimicrobial Activities of Non-Fermented and Fermented Seeds of Vitis vinifera

The fermented and non-fermented seed powder of Vitis vinifera, a herbaceous plant with numerous biological activities was investigated in this study. The pH, in vitro antimicrobial assay against Staphylococcus aureus, Escherichia coli, and Candida albicans, phytochemical, proximate compositions were screened, while the active compounds of the fermented sample were further evaluated by High-performance liquid chromatography (HPLC). A decline in pH from 6.2 to 3.6 was recorded during fermentation for 14 days. Varying MIC/ MFC ranges of 12.5 – 25.0 mg/mL and 12.5-100.0 were noted for the fermented and unfermented samples, respectively. The fermented sample exhibited appreciable antimicrobial effects with varying inhibition zones at tested concentrations of 100 mg/mL (10.0-18.0 mm), 50 mg/mL (8.0-15.0 mm), and 25 mg/mL (6.0-12.0 mm) than the unfermented sample with inhibition zone at concentrations of 100 mg/mL, 50 mg/mL, and 25 mg/mL being 2.0-3.0 mm, 0.0-2.0 mm, and 0.0-2.0 mm, respectively. Ash, fat, and protein content increased with fermentation than moisture, fiber, and carbohydrate content. Alkaloids, anthraquinone, flavonoids, glycosides, saponins, tannins, and terpenoids were detected in the fermented sample while alkaloids, flavonoids, glycoside, saponins, and terpenoids were detected in the non-fermented sample. Gallic acid, quercetin, catechin, quercitrin, and epicatechin were detected by HPLC in the fermented samples. Conclusively, fermented, and non-fermented samples of V. vinifera have antimicrobial activities, however, the acidity of the fermented sample may be contributing to its better activity and higher components. Thus, their relevance as promising antimicrobial agents