Study On Oat β-Glucan Solution And Gel Properties

Our country is the main origin of naked oats; β-glucan extracted from oat is water-soluble dietary fiber, with excellent physiological health function such as lowering blood sugar and lipids. In this paper, GY-8 families produced in Shanxi were used as materials and obtained β-glucan Glu-0 with purity of 89.2% by enzymatic extraction. Hydrolysis Glu-0 with dilute hydrochloric acid obtained P-glucan of different molecular weight:Glu-1, Glu-2, Glu-3, and Glu-4. The molecular weights measured by GPC-MALLS were 61.26×104,46.55×104, 39.94×104,14.49×104, and 4.66×104.IR spectrum of the sample that showed β-glucan is a polysaccharide consists of P-D pyranose residues linked by β-(1â†'3)-and β-(1â†'4)-glycosidic linkage. XRD patterns showed that P-glucan itself does not form a crystalline structure. Observation by SEM showed that with the reduction of molecular, the microstructure morphology of P-glucan transformed from the interleaved long flaky to single loose spherical gradually.Study on pyrene fluorescence probes showed that hydrophobic domain hardly exist at a lower β-glucan concentration in aqueous solution. With increasing concentration, β-glucan molecule aggregate with each other gradually and form hydrophobic domain. Besides, the molecular weight increases is in favor of the formation of hydrophobic domain. Adding NaCl can promote forming hydrophobic domains, while the presence of urea can destroy intermolecular hydrogen bonds, hinder the formation of hydrophobic domain between β-glucan molecules.By low-field NMR, we study the motion state of water in β-glucan solution, the results showed that there are two different status of water in β-glucan solution: bound water and free water. In β-glucan solutions of different concentrations, different molecular weights, free water and bound water can migrate and transform with each other, however storage time had little effect on moisture status of β-glucan solution system.Study on rheological properties of β-glucan solution found that β-glucan solution showed only the viscous characteristics of fluid in low concentration, while in high concentration, β-glucan solution showed both the viscous characteristics of fluid and the elastic properties of colloid, besides β-glucan of high concentration and high molecular weight contribute to its enhancement of elastic properties.Study on the gel-forming conditions of β-glucan found that higher concentration and lower molecular weight is advantageous to form β-glucan gel. In this study, when β-glucan was of higher concentration and lower molecular weight, the gel possessed higher stability, elasticity and strength.