Abstract:The extraction of β-glucan from highland barley bran was conducted using an aqueous extraction method. The extraction rate of β-glucan was utilized as the evaluation metric to optimize the extraction process of β-glucan from highland barley bran through single-factor and response surface tests. The purification process of β-glucan from highland barley bran was optimized with the purity and extraction rate of purified β-glucan as the primary evaluation metrics. The findings indicated that the most effective extraction process for β-glucan from highland barley bran was as follows： a pH of 8， a material-liquid ratio of 1∶20 （g/mL）， an extraction temperature of 66 ℃， and an extraction time of 2.25 h. The extraction rate of β-glucan under these optimal conditions was （5.027±0.064）%， which was in accordance with the predicted value of 5.014%. The optimal purification conditions for β-glucan from highland barley bran were as follows： The experiment was initiated by adding α-amylase （50 U/L） to the extract in a water bath at 60 ℃ for 1 h. Subsequently， saccharase （250 U/L）was added， and the mixture was subjected to the same temperature and duration of water bath. Centrifugation at 3 000 r/min was then employed to concentrate the supernate. The mixture was then subjected to alcoholic precipitation， followed by reconstitution in hot water. The precipitates were then subjected to freeze-thawing，centrifugation， and freeze-drying to form the precipitates. After a purification process， the purity of the β-glucan from highland barley bran was determined to be （77.50 ± 0.60）%. The inhibitory potential of the obtained β-glucan on pancrelipase was subsequently assessed， revealing that at a concentration of 10.0 mg/mL， the βglucan from highland barley bran exhibited a pancrelipase inhibition rate of up to 76.70%. In summary， the optimized extraction process of β-glucan from highland barley bran was characterized by simplicity， stability，and ease of implementation. The resulting β-glucan product exhibited significant in vitro hypolipidemic activity.