Stability and adhesion properties of Lacticaseibacillus rhamnosus GG embedded in milk protein cryogels: Influence of plant seed gum inclusion

Abstract

This work reports on the influence of plant seed gum (PSG) from alfalfa (Medicago sativa L.) and flaxseed (Linum usitatissimum L.) on cryogels based on sodium caseinate (NaCas), whey protein isolate (WPI), and their combined mixture in embedding the probiotic Lacticaseibacillus rhamnosus GG (LGG). A significant preservation of LGG cell viability was achieved during the xero-structuration process. Among the materials tested, sodium caseinate was the standout, most effectively preserving LGG's biological activity across varying temperature and humidity conditions. Elevated storage temperature and relative humidity conditions accelerated LGG inactivation rates, especially in the case of WPI (in the presence or absence of PSG), which was primarily attributed to increased metabolic activity due to the changes in the xero-scaffolds’ physical state. Moreover, the specific protein type used played a pivotal role in determining LGG's survival rates during simulated gastrointestinal digestion processes. In adhesion tests using a Caco-2/HT-29 co-culture model, LGG showed the highest adhesion found in NaCas. Interestingly, except for NaCas, adding PSG augmented LGG's bioadhesion capabilities, with flaxseed gum showing the highest enhancement in adhesin-mucin interactions. The research also underscored the release of bioactive peptides, which displayed a range of health benefits including antimicrobial and antioxidant properties.