PUL/HPMC water-in-water Pickering emulsions: A food-grade microculture platform for efficient encapsulation and cultivation of Lactobacillus plantarum.

In this study, pullulan-in-hydroxypropyl methylcellulose (PUL/HPMC) water-in-water Pickering emulsions stabilized by cellulose nanocrystals (CNCs) were prepared for the encapsulation and cultivation of L. plantarum. Results demonstrated that CNCs were mainly adsorbed at the PUL-HPMC interface, thereby effectively inhibiting the aggregation and coalescence of emulsion droplets. L. plantarum was encapsulated in emulsions and primarily distributed in the PUL phase. It was found that the optimal encapsulation concentration of L.plantarum was 9.67 log CFU/g, and the optimal addition of MRS broth was 1.0 wt%. Finally, the viable counts of L.plantarum increased from 4.44 to 7.42 log CFU/g during 30 h of cultivation. Furthermore, an initial pH 5.5 afforded the optimal cultivation performance for L.plantarum, with viable counts increasing from 4.00 to 7.06 log CFU/g during 24 h of cultivation. This study provides a novel microculture platform for efficient L.plantarum cultivation and fully aqueous emulsion systems with food-grade application potential for probiotics-based functional foods.