Combinedly increased viability of Lactiplantibacillus plantarum grx16 by co-encapsulation of cryoprotectants and porous starch within calcium alginate capsules

Alginate-based encapsulation is an effective probiotics delivery system in the intestine. However, due to calcium ions and gastric juice damaging cell wall/membrane integrity during freeze-drying and gastrointestinal ingestion, lots of cell lose their viability. This study, taking Lactiplantibacillus plantarum grx16 as an example, indicated that co-encapsulation of cryoprotectants and porous starch within calcium alginate capsules (CAC) could combinedly improve the viability of probiotics encapsulated. Compared with calcium alginate-protectant capsule (CAC-Pro) (50.67%), the combination of porous starch increased the encapsulation rate of PS0.8-CAC-Pro to 82.68%. Meanwhile, the death rate constants of PS0.8-CAC-Pro decreased by 31.3% (-20 & DEG;C), 13.5% (4 & DEG;C) and 7.5% (25 & DEG;C), respectively. The survival rate of PS0.8-CAC-Pro was 81.94% after continuous simulated gastrointestinal digestion, which was significantly higher than that of CACs (69.46%) and CAC-Pro (76.92%). This study provided an effective approach for modifying alginate capsule to reduce the loss of probiotics viability.