Changes in physicochemical and functional properties of Opuntia humifusa during fermentation with cellulolytic enzyme and lactic acid bacteria

Eastern prickly cactus (Opuntia humifusa) has a substantial therapeutic and dietary value. In this study, O. humifusa plants were fermented at 25 C with cellulolytic enzymes (E, Viscozyme), lactic acid bacteria (LAB), Lactobacillus paraplantarum (Lp), Streptococcus salivarius (Ss), and Weissella confusa (Wc) in various combinations: E, LWS (Lp:Wc:Ss = 1:1:1, v/v/v), and E with LAB (E-Lp, E-Ss, E-Wc, and E-LWS). Significantly lower viscosity (14.5 cP) and higher yield (> 97.4%) were observed in O. humifusa extracts containing E (P < 0.05), whereas the extract with LWS showed the highest viscosity (36.9 cP) and lowest yield (58.8%). Total polyphenol content and antioxidant activity of O. humifusa extract were enhanced, and flavonoid glycosides (isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside) were effectively converted to aglycones when fermentation was performed with E and LAB. The isorhamnetin and quercetin contents were highest in the E-Wc and E-LWS extracts fermented for 60 h. This study shows that the physical and functional properties of O. humifusa extract may be modulated by fermentation with selected LAB and cellulolytic enzymes.

Automated summary

This study demonstrates that fermentation with selected LAB and cellulolytic enzymes can modulate the physical and functional properties of O. humifusa extract. Extracts containing cellulolytic enzymes showed lower viscosity and higher yield, while fermentation process enhanced the total polyphenol content and antioxidant activity. Furthermore, flavonoid glycosides were effectively converted to aglycones during fermentation.