Encapsulation Effect, Physicochemical and Gastrointestinal Properties of Lactobacillus plantarum Microcapsules

The main purpose of this research was to study the effects of encapsulation, physicochemical properties and gastrointestinal performance of Lactobacillus plantarum microcapsules, which were prepared via the sharp-hole coagulation technique using arabinoxylan and sodium alginate as wall materials and Lactobacillus plantarum as a core material, respectively. The encapsulation yield was 73.60%±0.01%, the embedding efficiency was 81.27%±0.17% and the effective load was (3.68±0.4)×10¹¹ cfu/g. Furthermore, The angle of repose was (35.25±4.35)°, the moisture content was 8.82%±0.01% and the density was (0.25±0.01) g/cm³. The SEM images clearly showed the complete and compact surface structure of the microcapsules, therefore, it had a good protective effect on Lactobacillus plantarum. The results obtained from gastrointestinal simulation indicated that the microcapsules had low acid solubility and high intestinal solubility. The acid resistance test showed a decrease in the number of bacteria loaded in microcapsules by only 1.2lg (cfu/mL) whereas bacterial suspension decreased by 6.4lg (cfu/mL). The intestinal release test showed that the microcapsules were completely released after 1 h. The number of bacteria loaded in microcapsules decreased by only 0.55lg (cfu/mL) whereas the bacterial suspension decreased by 5.6lg (cfu/mL) for the continuous gastrointestinal tests. Additionally, the microcapsules were stored at -20, 4 and 28℃ for 7 weeks, respectively. The number of bacteria decreased by 1.2lg, 1.7lg and 5.2lg (cfu/mL), which indicated that low temperature storage was more beneficial for the preservation of Lactobacillus plantarum. In summary, the microcapsule had a good encapsulation effect on Lactobacillus plantarum and could provide sufficient protection for it.