Study on encapsulation of Lactobacillus plantarum 23-1 in W/O/W emulsion stabilized by pectin and zein particle complex

This study was conducted to develop a W/O/W emulsion encapsulated Lactobacillus plantarum 23-1 (LP23-1) to significantly enhance the survival rate of LP23-1 under simulated digestion and storage conditions. The zein particles and pectin formed a complex through electrostatic interaction and hydrogen bonding. When the proportion of zein particles to pectin was 1:1, the emulsifying stability index (ESI) was 304.17 %. Additionally, when the proportion of the internal aqueous phase to the oil phase was 1:9, the polyglycerol polyricinoleate (PGPR) concentration was 5 %, the proportion of primary emulsion to the external aqueous phase was 5:5, the zein particles concentration was 4 %, and the proportion of zein particles to pectin was 1:1, the encapsulation rate was the highest at 96.27 %. Cryo-scanning electron microscopy and fluorescence microscopy confirmed the morphology of W/O/W emulsion and successful encapsulation of LP23-1. Furthermore, compared with free LP23-1, the W/O/W emulsion encapsulation significantly improved the survival rate of LP23-1 to 73.36 % after simulated gastrointestinal digestion and maintained a high survival rate of 78.42 % during the 35-day storage. The W/O/W emulsion was found to effectively improve the survival rate of LP23-1 during simulated digestion and storage, which has implications for the development of probiotic functional foods with elevated survival rates.