Effect of Different Carbohydrates on Gel Properties of Grass Carp Surimi

The effects of dextran, sucrose, trehalose, xylo-oligosaccharide and fructooligosaccharide on the microstructure, gel protein structure, water molecule fraction and texture characteristics of grass carp surimi were studied. SEM results showed that compared with the blank sample, the surimi gel with 4% dextran, sucrose and trehalose could observe a tighter network structure. The addition of sugar promoted the crosslinking of protein and the tightness of gel network structure, and improved the gel characteristics of surimi products. The proportion of surimi protein α-helix structure in the samples added with fructooligosaccharides decreased. Compared with the blank sample, the α-helix content of the sample added xylooligosaccharides increased significantly (P<0.05) by 3.59%. Different sugars would change the distribution of water molecules in surimi gel. Except sucrose, the relaxation time of immobile water and free water in surimi gel increased, and the ratio of bound water and immobile water increased; The hardness and chewiness of grass carp surimi gel decreased significantly with 5 kinds of sugars, but the texture properties of surimi gel with dextran and sucrose was higher than other sugars.