title: Shear and extensional properties of kefiran.
abstract: Kefiran is a neutral polysaccharide constituted by glucose and galactose produced by Lactobacillus kefiranofaciens. It is included into kefir grains and has several health promoting properties. In the present work, shear and extensional properties of different kefiran aqueous dispersions (0.5, 1 and 2% wt.) were assessed and compared to other neutral gums commonly used in food, cosmetic and pharmaceutics industries (methylcellulose, locust bean gum and guar gum). Kefiran showed shear flow characteristics similar to that displayed by other representative neutral gums, although it always yielded lower viscosities at a given concentration. For each gum system it was possible to find a correlation between dynamic and steady shear properties by a master curve including both the apparent and complex viscosities. When studying extensional properties of selected gums at 2% wt. by means of a capillary break-up rheometer, kefiran solutions did not show important extensional properties, displaying a behaviour close the Newtonian.
authors: Centro de Investigación y Desarrollo en Criotecnología de Alimentos(CIDCA), CONICET, Facultad de Ciencias Exactas, UNLP, 47 y 116, La Plata, Argentina.
authors: Judith
authors: J
authors: Piermaría
authors: Departamento de Ingeniería Química, Universidad de Sevilla, Facultad de Química, Calle Profesor García González 1, 41012 Sevilla, Spain. Electronic address: cbengoechea@us.es.
authors: Carlos
authors: C
authors: Bengoechea
authors: Centro de Investigación y Desarrollo en Criotecnología de Alimentos(CIDCA), CONICET, Facultad de Ciencias Exactas, UNLP, 47 y 116, La Plata, Argentina; Área Bioquímica y Control de Alimentos, Facultad de Ciencias Exactas, UNLP, 47 y 115, La Plata 1900, Argentina.
authors: Analía Graciela
authors: AG
authors: Abraham
authors: Departamento de Ingeniería Química, Universidad de Sevilla, Facultad de Química, Calle Profesor García González 1, 41012 Sevilla, Spain.
authors: Antonio
authors: A
authors: Guerrero
mesh_terms: D007778:Lactobacillus / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D033081:Shear Strength; D014783:Viscosity
chemical_list: D011134:Polysaccharides; C050180:kefir grain polysaccharide
keywords: Cross; Extensional viscosity; Kefiran; Neutral gum; Rheology