Enterococcus faecalis-Aided Fermentation to Facilitate Edible Properties and Bioactive Transformation of Underutilized Cyathea dregei Leaves

Cyathea dregei (CD) is a weed plant that is rarely consumed. This study investigated the impact of Enterococcus faecalis as an agent of 3-5-day fermentation, thus stimulating the edible properties of the leaves from CD using Talinum fruticosum as the control. The proximate content, biochemical, antioxidant properties, and phytochemical constituents of the unfermented and fermented leaves were examined. The lactate dehydrogenase activity (LDH) activity significantly increased (p < 0.05) due to the fermentation, which peaked on the third day. The fat, ash, and crude fiber constituents of the fermented CD leaves were significantly higher (p < 0.05), especially on day 3, compared to the unfermented leaves of CD. The leaves of CD naturally possess significantly higher (p < 0.05) values of calcium, selenium, magnesium potassium, sodium, zinc, and vitamin C but significantly lower (p < 0.05) values of vitamins A and E compared to those of water leaf. The fermentation aided the synthesis of caffeic acid (61.71 mg/10 g extract), eleven other bioactive phytochemicals (0.14-60.24 mg/10 g extract), two unexplored saponins (P-Scd, 52.05 mg/10 g extract), and a phenolic compound (P-Pcd, 0.23 mg/10 g extract). Four novel intermediary compounds and six other established compounds were freshly identified with fermentation. The leaves of C. dregei are naturally rich in bioactive nutrients and phytochemicals that trigger their strong antioxidant qualities, which were improved by this fermentation technique. E. faecalis is most likely to engage LDH in driving the fermentation transforming the C. dregei into a potential edible vegetable.