Improved viability of probiotics encapsulated by layer-by-layer assembly using zein nanoparticles and pectin

The objective of this research was to encapsulate probiotics in zein nanoparticles (ZNP) and pectin using layer-by-layer (LbL) assembly, and investigate the influences on cell viabilities during freeze-drying, gastrointestinal digestion, heating and storage. High survival rates (>95%) were obtained during fabrication process. The increasing in coating layers would enhance the density of surface structure, however, poor correlated with the cell viabilities during heating and storage. Pectin as outmost layer would promote the viability during heating (0.61 Log CFU/mL loss), while ZNP instead was more beneficial during storage (0.21 Log CFU/mL loss). During gastrointestinal digestion, with deficient coating layers, dissolution of pectin would exposure cells to harsh conditions faster, however, with sufficient coating, this adverse impact can be offset. Hence, the current study demonstrated that for LbL assembled probiotic microcapsules, the matrix of outmost layer and number of coating layers played an important role in cell viabilities to external adverse conditions.