Preparation of probiotic microcapsules using gelatin-xylooligosaccharides conjugates by spray drying: Physicochemical properties, survival, digestion resistance and colonization

Limosilactobacillus fermentum NCU001464 is a probiotic bacterium with anti-hyperuricemia potential, however, its viability decreases during food processing, storage and in the gastrointestinal tract. This study aims to microencapsulate Limosilactobacillus fermentum NCU001464 by spray-drying with Maillard reaction products of gelatin and xylooligosaccharides, heated for various times. Properties of powders and bacterial vitality change during producing, storage and simulated digestion were evaluated. The microcapsules had a low moisture content and the encapsulation appeared effective, however, under scanning electron microscope, cracks were visible on the surface of microcapsules with longer-time heat-treated Maillard reaction products. Heat treatment for 60 min resulted in the highest bacterial viability and adhesion capacity to intestinal epithelial cells after gastrointestinal digestion. After 10 weeks storage at 4 °C and 25 °C, the viable count of MRP-microencapsulated cells was 9.00–6.80 Log CFU/g, more than the recommended dose of 6 Log CFU/mL.