Kefiran: a promising microbial polysaccharide for application in functional foods and biomedical industries

Abstract

Kefiran, a high-molecular weight exopolysaccharide produced by microorganisms present in the kefir grains or in the fermented milk prepared with them, has displayed an increased attention on account of its physicochemical properties and biological activity. Several health-promoting properties of kefiran such as epithelium protection against toxigenic factors of Bacillus cereus, antitumoral activity or bifidogenic activity have been reported. Futhermore, antimicrobial, antioxidant or wound healing activity were also reported. Kefiran has a Newtonian behaviour in diluted solutions but pseudoplastic at high concentrations and has promising technological application since it has the ability to increase viscosity and improve viscoelastic properties of acid milk gels, forms viscoelastic gels at low temperature and is able to form transparent films with good mechanical properties as well as can contribute to emulsion stability. Kefiran or kefiran-whey proteins-based films are interesting matrix as carriers of probiotics. Kefiran cryogels were also considered as scaffold for tissue engineering or skin repair. Therefore, kefiran arise as a novel biopolymer with a wide range of applications in food and biomedical industries.