104: Comparative Evaluation of Emulsification-Based Microencapsulation Techniques With Soy Protein Isolate for Enhanced Shelf-Life and Delivery of Lactobacillus Rhamnosus GG

Introduction

Soy protein isolate (SPI) is widely used as a wall material in emulsification-based microencapsulation due to its excellent solubility, water and fat absorption, and emulsifying properties. However, most research has focused on single microencapsulation techniques, and few studies have comprehensively compared different emulsification-based microencapsulation methods using SPI as a common encapsulant. By maintaining a consistent SPI concentration across different techniques, this study aims to comprehensively assess how the choice of encapsulation method influences the storage stability and survival of LRGG in the GI tract.

Methods

Five different types of microencapsulation were employed using 3% (w/w) SPI, including a water-in-oil-in-water (W/O/W) emulsion, external gelation with sodium alginate, a water-in-oil (W/O) emulsion with pectin, a W/O/W emulsion with pectin, and a W/O/W emulsion with external gelation, to entrap Lactobacillus rhamnosus GG (LRGG). The initial number of cells was set to 9 Log CFU/g. The storability of free and entrapped LRGG at 4°C was studied for up to 8 weeks. The survival of cells in simulated gastrointestinal conditions was also tested using in vitro static models.

Results

The entrapped LRGG in W/O/W emulsion and external gelation showed extended shelf-life in cold storage compared to free cells, while single emulsion and the addition of pectin did contribute to enhancing the storability of LRGG. The survivability of LRGG in double emulsion and external gelation samples also exhibited better stability in the simulated gastric and intestinal juices. The greatest stability of LRGG in both storage and digestions was observed in microcapsules with external gelation, and the combination of double emulsion and external gelation showed slightly better stability only in gastric digestions.

Significance

This study successfully compared the efficacy of different microencapsulation techniques for the entrapment of probiotics using the fixed concentration of SPI. The findings confirmed that both external gelation and W/O/W emulsions were highly effective in enhancing the shelf-life of LRGG during cold storage, as well as in improving its delivery through the human GI tracts.

Authors: Toshifumi Udo, Ethan He, Zijin Qin, Rakesh K. Singh, Fanbin Kong*