Development of a combined low-methoxyl-pectin and rice-bran-extract delivery system to improve the viability of Lactobacillus plantarum under acid and bile conditions

- Probiotic cells can load in pectin and rice bran extract capsules (PE-RB capsules).
- PE-RB capsules can protect the probiotic cells from acid and bile.
- PE-RB capsules influence the viability of probiotics cells.

A combined pectin-rice bran delivery system for Lactobacillus plantarum NRRL-B4496 (LP) was developed. Four pectin (PE)-rice bran extract (RB) gel solutions were prepared: (1) 2.0 g/100  mL PE with 0.5 g/100 mL RB, (2) 2.0 g/100  mL PE with 1.0 g/100 mL RB, (3) 2.0 g/100  mL PE with 2.0 g/100 mL RB, and (4) 2.0 g/100  mL PE (control). L. plantarum was grown in MRS broth, centrifuged, and mixed with the gel solutions. The capsules loaded with L. plantarum (LP/PE-RB capsules) were then prepared by ionotropic gelation. PE-RB gel solutions exhibited pseudoplastic behavior. The gel solution containing 2.0 g/100 mL RB had the highest consistency and viscosity. All LP/PE-RB capsules had similar diameter size. Both the sphericity and the encapsulation efficiency of the capsules were increased with higher RB content, while the hardness and springiness were decreased. When exposed to acidic and bile salt conditions, the viability of encapsulated cells was higher than free cells. The study demonstrated that pectin-rice bran capsules could have potential as a delivery system for L. plantarum.