Microencapsulation of Lactobacillus rhamnosus GG with Resistant Starch and Xanthan Gum

Abstract

Microencapsulation is the most common method in improving probiotic survivability against adverse conditions. In this research, resistant starch was incorporated as prebiotic coating material during the microencapsulation of Lactobacillus rhamnosus GG (LGG) in calcium alginate beads coated with xanthan gum. Three types of microcapsules were produced: LGG only, LGG with resistant starch, and LGG with resistant starch and xanthan gum coating. The size and morphology of microcapsules were measured. Furthermore, the viability for free cells and microencapsulated LGG was tested in the simulated gastric juice (SGJ) (pH 2.0, 2 h) and simulated intestinal juice (SIJ) (pH 7.5, 4 h). The results indicated that 2.0 %(w/v) resistant starch and 0.3 %(w/v) xanthan gum had the highest microencapsulation efficiency (MEE). The morphology for microencapsulated LGG was spherical and white. The mean diameter for all 3 types of microcapsules was in between the range of 562.67 to 614.33 μm and xanthan gum-coated microcapsules had the highest MEE of 84.67 %. The addition of resistant starch and xanthan gum had increased the MEE for encapsulated probiotics. Both encapsulated LGG with and without xanthan gum coating had higher survivability than free cells, which indicated the positive role of resistant starch and xanthan gum in promoting the viability of probiotics during gastrointestinal transit. In general, co-extrusion encapsulation and the addition of resistant starch and xanthan gum coating could protect the viable LGG against the harsh human gastrointestinal condition. HIGHLIGHTS Microencapsulation of Lactobacillus rhamnosus GG using co-extrusion technique LGG encapsulated with resistant starch as wall material and xanthan gum coating Xanthan gum coated-LGG microbead displays highest microencapsulation efficiency Xanthan gum coated-LGG microbeads survives simulated gastrointestinal transit Co-extrusion technique had a positive impact on the viability of LGG GRAPHICAL ABSTRACT