Microencapsulation of Lactobacillus plantarum with enzymatic hydrolysate of soybean protein isolate for improved acid resistance and gastrointestinal survival in vitro

This study aimed to improve the acid resistance effect of Lactobacillus plantarum through microencapsulation with enzymatic hydrolysate of soybean protein isolate (EHSPI) and modified phospholipid. Response surface methodology was adopted to establish the optimal microencapsulation technology of L. plantarum, while coating characters were evaluated. Through response surface methodology, the optimal conditions were obtained as follows based on microencapsulation efficiency: the ratio of bacteria/EHSPI 1:1.83, EHSPI content 4.01%, modified phospholipid content 11.41%. The results of digestion in vitro showed that after passing through the simulated gastric fluid (SGF), the L. plantarum was released and reached 3.55 x 10(8) CFU/mL in the simulated intestinal fluid. Meanwhile, the surviving bacteria number of control significantly decreased to 2.63 x 10(4) CFU/mL (P < 0.05) at 120 min in SGF. In sum, the acid resistance and survival of L. plantarum were improved in SGF in vitro, through the microencapsulation technology based on EHSPI.