Study On Extraction And Antioxidant Activities Of Polysaccharides From Corbicula Fluminea

Corbicula fluminea is one of the most important economic aquatic products. Due to its high quality, delicious taste, nutrition and so on, it enjoyed a high reputation at home and abroad market such as Japan and South Korea. Farming area of Corbicula fluminea in China is large and its yield is high, its development and utilization has great potential. There were many studies on animal polysaccharides of natural resources recently, but there were few reports on the Corbicula fluminea polysaccharides. This paper focused on the extraction, purification, antioxidant activity assay of polysaccharides from Corbicula fluminea.1. Optimization of enzymolysis extraction technologyUsing Corbicula fluminea as raw maerial, the content of polysaccharides was determined by the phenol-sulphate acid method. On the basis of single factors tests, the effects of the four factors including temperature, solid-liquid ratio, pH and amount of enzyme on the yield of polysaccharides from Corbicula fluminea were studied through the orthogonal experiment design. The results showed that factors affecting the yield of polysaccharides as following order:temperature> pH> amount of enzyme> solid-liquid ratio while temperature had significant effect on the yield of polysaccharides (p< 0.05). And the amount of enzyme, solid-liquid ratio, pH of extraction had no significant effect on the yield of polysaccharides. The optimum technological parameters were as follows:solid-liquid ratio 1:30, temperature 55℃, amount of enzyme 1.5% and pH 7.5. The yield of polysaccharides was 4.53% under the optimum experiment parameters.2. Optimization of ultrasonic-assisted enzymolysis extraction technologyUsing Corbicula fluminea as raw material, the content of polysaccharides was determined by the phenol-sulphate acid method. On the basis of single factors tests, the effects of the four factors including ultrasonic time, solid-liquid ratio, digestion time and ultrasonic power on the yield of polysaccharides from Corbicula fluminea were studied through orthogonal experiment design. The results showed that the decreasing order of effect of the four factors on extraction yield of polysaccharides were ultrasonic time> solid-liquid ratio> digestion time> ultrasonic power, in which ultrasonic time had significant effect on the yield of polysaccharides (p< 0.1). And solid-liquid ratio, digestion time and ultrasonic power had no significant effect on the yield of polysaccharides. The optimum parameters were as follows:ultrasonic time 40 min, ultrasonic power 80W, solid-liquid ratio 1:30 and digestion time 90 min. The yield of polysaccharides was 4.86% under the optimum experiment parameters.3. Monosaccharide composition analysisThe monosaccharide composition of polysaccharides from Corbicula fluminea was analyzed by high performance liquid chromatography (HPLC) after pre-column PMP derivatization. The HPLC results showed that polysaccharides from Corbicula fluminea was composed of seven kinds of monosaccharides at least, including Man, GlcN, GlcUA, GalN, Glc, Gal and Fuc, and GlcN, Glc and Fuc were main.4. Antioxidant activity researchMaking ascorbic acid as control, the antioxidant activity of the above two different extracts from Corbicula fluminea were determined by DPPH assay and ABTS assay. The results suggested that CFPS1 and CFPS2 showed potent antioxidant activity, however, antioxidant activities of the two extracts were much lower than the positive control. The antioxidant capability of CFPS1, CFPS2 and ascorbic acid decreased in the order of ascorbic acid> CFPS2> CFPS1.