β dextranase

G. lemaneiformis was collected from the coast of Xiapu, Fujian, China (26°42′ N, 119°59′ E). Pectinase (500,000 U/g), glucoamylase (100,000 U/g), cellulase (50,000 U/g), xylanase (6,000,000 U/g), β-dextranase (50,000 U/g), and standard samples were purchased from Shanghai Yuanye Biotechnology Co, Ltd. (Shanghai, China). DPPH was purchased from McLean Biochemical Technology Co., Ltd., (Shanghai, China). All other chemicals were of analytical grade. The reagents and kits used in the cell experiment were purchased from Solarbio Science & Technology Co., Ltd. (Beijing, China). HFL1 cells and complete culture medium were obtained from iCell Bioscience Inc. (Shanghai, China).

Ctenopharyngodon idellus is a widely cultivated edible freshwater fish in China, which is not an endangered or specially protected species. All methods used in this study were conducted in accordance with the guidelines of the Chinese Laboratory Animal Use and Care Legislation.
Fresh grass carp (Ctenopharyngodon idellus) was purchased from the Hubei Academy of Agricultural Science market (Wuhan, Hubei, China) and then transported to the laboratory alive in clean oxygenated water. Fish were exposed and immersed in ice/water slurry (temperature = 1 ± 1 °C) until no opercular movements were observed. Then, the sacrificed fish were decapitated, scaled, viscera, sliced, and washed. KGM was purchased from Hubei Konson Konjac Co., Ltd. (Ezhou, Hubei, China). β-dextranase (50,000 U/g) was purchased from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). All other chemical reagents were of analytical grade.