Survival Behavior of <i>Lactobacillus plantarum</i> Loaded in Alginate/Konjac Glucomannan Composite Beads Under Storage and Gastrointestinal Conditions

Encapsulation techniques are commonly used to preserve the viability of probiotics during storage and digestion. In this paper, composite beads were developed using sodium alginate (ALG) and konjac glucomannan (KGM) by calcium cross-linking, and were further used to entrap <i>Lactobacillus plantarum</i> for withstanding adverse environments. The results showed that the ALG/KGM solution displayed solid-like behavior after KGM addition. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that the beads were prepared through crosslinking agent ions with the carboxylate functional groups. The encapsulation efficiency (EE) of the ALG/KGM bead with ratios of 1:3 (AK13) reached 81.5% with a loading capacity (LC) of 8.15 log CFU/g. Besides, the ALG/KGM beads enhanced the storage stability at 4°C. <i>L. plantarum</i> count continually increased with a maximum of 11.8 log CFU after 40 min gastric digestion. The work confirmed that the ALG/KGM bead was an excellent probiotic protective carrier for <i>L. plantarum</i>.