W/O/W emulsions stabilized with whey protein concentrate and pectin: Effects on storage, pasteurization, and gastrointestinal viability of Lacticaseibacillus rhamnosus

Abstract

Probiotics have demonstrated various bioactive functions but poor storage and application stability, and encapsulation a promising method of increasing its viability. In this study, whey protein concentrate (WPC) and pectin (PEC) formed non-covalent complexes through electrostatic interaction at pH 3.0. The formed WPC-PEC complexes showed superior particle size, absolute potential, emulsification properties, and structural changes when PEC concentration was >0.8 % (w/v). This made them appropriate as a hydrophilic emulsifier to stabilize W/O/W emulsions. Then, Lacticaseibacillus rhamnosus, one representative of probiotics, was encapsulated in the internal aqueous phase of W/O/W emulsions. We obtained higher encapsulation efficiency (78.49 %) and smaller D_4,3 (9.72 μm) with 0.8 % (w/v) PEC concentration. Encapsulation of Lacticaseibacillus rhamnosus in W/O/W emulsions improved its viability under harsh conditions, including 28 days storage at 4 °C, simulated pasteurization, and simulated gastrointestinal digestion. W/O/W emulsions stabilized by WPC-PEC non-covalent complexes further improved the survival of Lacticaseibacillus rhamnosus against various adverse conditions as compared to WPC. These findings suggest that the studied W/O/W emulsions systems have the potential to deliver probiotics in food substrates to enhance their viability during production processing, storage transportation, and digestion.

Keywords: Encapsulation; Lacticaseibacillus rhamnosus viability; Pectin; W/O/W emulsions; Whey protein concentrate.