Sustainability and controlled release behavior of microencapsulated Lactobacillus plantarum PRK7 and its application in probiotic yogurt production

Probiotics are used as potential constituents in functional foods and their demand is increasing due to their health benefits. However, to endure the probiotics in intestinal transit and food processing is challenging from a future health perspective. Microencapsulation technique promotes sustainable release at the target site. Lactobacillus plantarum PRK7 was microencapsulated with sodium alginate (SA), inulin (SA-I) and skim milk (SA-SK) formulations as encapsulating material to study its influence on food products. The physicochemical features and behavior activities of the microbead formulations were analyzed by scanning electron microscopy, Fourier-transformed infrared, X-ray diffraction methods and encapsulation efficiency, swelling and erosion ratio, hygroscopicity, and viability studies. The physicochemical studies revealed their smooth surface, size ranging from 405 to 511 μm, and amorphous nature. The encapsulation efficiency of SA, SA-I, and SA-SK microbeads were 96.05% ± 0.85%, 92.77% ± 1.26%, and 93.98% ± 1.68%, respectively. The controlled release mechanism of microbeads in the simulated gastric juice was confirmed by studying their swelling and erosion properties. The SA, SA-I, and SA-SK microbeads exhibited 18.14 ± 1.85, 2.98 ± 1.35, and 31.25 ± 1.05 g (hygroscopicity); 0.40 ± 0.12, 0.35 ± 0.15, and 0.13 ± 0.08 g/ml (dispersibility); and 5.3 ± 1.2 × 107, 6.5 ± 1.8 × 108, and 6.02 ± 1.5 × 107 CFU/g (viability), respectively. Further, the in vitro toxicity study was conducted using zebrafish embryos, which confirmed their nontoxic nature. Sensory evaluation was performed by 21 panelists using the nine-point hedonic scale. The SA-I formulation showed the highest overall acceptability score of 8.28 ± 0.64 compared to other formulations. Thus, from this study it was confirmed that the produced symbiotic microbeads would be beneficial in developing functional food products for future applications.