Optimization and Functional Study on Codonoposis bulleyana Forrest ex Diels Ferment with Lactic Acid Bacteria

PurposeThe aim of this study was to produce Codonopsis bulleyana Forrest ex Diels (CBF) ferment with potential health benefits.

MethodThe enzymatic hydrolysate was obtained by enzymatic hydrolysis of CBF with three combined enzymes of tannase, cellulase and pectinase. The optimal technique for enzymatic hydrolysis of CBF was determined by enzymatic hydrolysis rate; the optimal preparation process of CBF ferment with Lactobaciilus plantarum ST was evaluated through sensory analysis. The acid-base titration method, the forinol method, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate, agar perforation diffusion method and qRT-PCR were used to determine the titratable acid, protease activity, antioxidant capacity, antimicrobial activity and immunomodulatory effect of CBF ferment, respectively.

ResultsThe highest enzymatic hydrolysis rate (38.6%) was observed when mixed three enzymes at a ratio of 1∶1∶1 was used , the ratio of solid to liquid (g∶mL) was 1∶8, the amount of enzyme was 0.6%, pH 5, and the enzymatic hydrolysis temperature was 50 ℃ for 180 min. The optimal processing of fermented CBF with L. plantarum ST was found as follows: sucrose added at 8% (m/m), initial inoculation of 10⁵ CFU/mL, temperature of 37 ℃, 20 h of fermentation under anaerobic condition. The titratable acid content, protease activity and DPPH free radical scavenging capacity of CBF ferment were significantly increased by 17.42% (P < 0.05), 63.75% (P < 0.05) and 36.57% (P < 0.05), respectively. The inhibitory effect of CBF ferment on Escherichia coli, Salmonella typhimurium and Shigella flexneri was significantly stronger. In addition, CBF ferment significantly reduced tumor necrosis factor (TNF)-α-induced expression of inflammatory genes including IL8, NFKB1 and NFKB2 in HT-29 human intestinal epithelial cells.

ConclusionThe CBF ferment does not have unpleasant odor of CBF and unique taste, with significantly increased protease activity and antioxidant activity. Furthermore, CBF has the combined function of probiotics and active ingredients of CBF as evidenced by significant antibacterial activity and immunomodulation potential.