Digestive protection of probiotic Lacticaseibacillus rhamnosus in Ricotta cheese by monoglyceride structured emulsions

Abstract

Summary This research aimed at studying the potential use of monoglyceride (MG) structured emulsions (MSEs) as delivery and protective systems for probiotic bacteria in Ricotta cheese. To this purpose, a low‐fat commercial Ricotta cheese was added with MSEs formulated with milk, as water phase, and sunflower oil (MSE‐SO) or anhydrous milk fat (MSE‐AMF), as lipid phase. A commercial whole milk Ricotta cheese (W‐RC) was considered as reference. A probiotic Lacticaseibacillus rhamnosus strain was inoculated as free cells in W‐RC or embedded into the MSEs and added to the low‐fat Ricotta at the same reference fat content. After physico‐chemical characterisation, L. rhamnosus viability and sample destructuring behaviour upon in vitro digestion were evaluated. At the end of in vitro digestion, both W‐RC and sample containing MSE‐SO were unable to protect cells. By contrast, sample with AMF ensured a sufficient probiotic viability, even after 14 days of storage at 4 °C. This result was attributed to system composition and structure. During the gastric phase, the presence of caseins and MG‐AMF mixed structures induced the formation of clots, entrapping and protecting cells against the acidic pH of the stomach, as confirmed by confocal micrographs and particle size. During the intestinal phase, cell viability was guaranteed by the formation of mixed micelles promoted by MG. It was demonstrated that microbial cells located near MG structures where they found protection.

Application of Pickering emulsions in probiotic encapsulation- A review

“…The nanogel W/O/W emulsions were additionally encapsulated in alginate hydrogel beads, further improving protection, and providing a controlled release mechanism at the target site through pH-responsive behavior. In another set of studies, monoglyceride emulsion gels were investigated in the stabilization of O/W emulsions for food systems where these types of emulsions occur ( Melchior et al, 2021 , 2022 ; Marino et al, 2017 ). Contrary to W/O and W/O/W emulsions that are widely reported in the literature, the probiotic cells were present in the continuous phase, where they are more vulnerable to processing and digestive stresses.…”

Designing food for the elderly: the critical impact of food structure

“…(2022) 164 exploited monoglyceride structured emulsions to deliver Lactobacillus rhamnosus strain into ice-cream and ricotta cheese. The structure of these systems was able to protect the probiotic bacteria during food processing, storage, and further digestion.…”

“…For instance, Zhuang et al 163 used bigels made of soy lecithin-stearic acid oleogel in emulsion with a whey protein hydrogel to deliver the probiotic Lactobacillus acidophilus and Bifidobacterium lactis in yoghurt. Similarly, Calligaris et al (2018) 113 and Melchior et al (2022) 164 exploited monoglyceride structured emulsions to deliver Lactobacillus rhamnosus strain into ice-cream and ricotta cheese. The structure of these systems was able to protect the probiotic bacteria during food processing, storage, and further digestion.…”