Effect of microencapsulation using peanut protein concentrate combined with resistant starch and β-cyclodextrin on the viability of Lactobacillus plantarum Heal 19 during storage and in vitro digestion

In this study, resistant starch and β-cyclodextrin were added to peanut protein concentrate to create probiotic microcapsules that protect the viability of Lactobacillus plantarum Heal 19 during digestion and storage. The survival rate of probiotics after adding polysaccharides was 5.31–6.98 % higher than that when using protein alone. FTIR and XPS confirmed the formation of a stable structure between protein and polysaccharide. LF-NMR and DSC showed improved structural stability in the polysaccharide-added groups, with the dual-polysaccharide group (PSC) showing the strongest stability. During in vitro digestion, PSC group reduced bacterial loss to only 1.97 log CFU/mL and maintained the highest cell viability (8.38 log CFU/mL) after being placed at 4 °C for 56 days. CLSM indicated that the proportion of live probiotics was the highest in the PSC group. These results demonstrate that the incorporation of polysaccharides significantly improves the cellular viability of probiotics during both digestion and storage. • Microencapsulation is a useful method for reducing the loss of probiotic vitality. • LF-NMR and DSC analyses confirmed that PSC had the highest structural stability. • PSC group exhibited the lowest cell viability loss under identical storage conditions. • In vitro digestion results showed that PSC had lower vitality loss than PPS, PPC, PP. • Polysaccharides can compensate for the limitations of protein-based microcapsules.