Grapefruit peel polysaccharide has antioxidant, antitumor, hypoglycemic and other biological activities, and chemical modification can further improve the properties of the polysaccharide. Acetylation modification of polysaccharides has the advantages of simple operation, low cost and little pollution, and is widely used at present. Different degrees of acetylation modification have different effects on the properties of polysaccharides, so it is necessary to optimize the preparation technology of acetylated grapefruit peel polysaccharides. In this article, acetylated grapefruit peel polysaccharide was prepared by acetic anhydride method. With the degree of acetyl substitution as the evaluation index, combined with the analysis of sugar content and protein content in the polysaccharide before and after modification, the effects of three feeding ratios of 1:0.6, 1 : 1.2 and 1 : 1.8 (polysaccharide: acetic anhydride, mass/volume) on acetylation modification were explored through single factor experiments. The results showed that the optimum ratio of material to liquid for acetylation modification of grapefruit peel polysaccharide was 1:0.6. Under these conditions, the degree of substitution of acetylated grapefruit peel polysaccharide was 0.323, the sugar content was 59.50 % and the protein content was 1.038 %. The results provide some reference for the study of acetylated grapefruit peel polysaccharide.
Keywords: acetylation; grapefruit peel polysaccharide; structural characterization.
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