Study on Extraction Process of Sipunculus nudus Polysaccharide and Its Antioxidant Activity

[Objectives] This study was conducted to optimize the extraction process of Sipunculus nudus polysaccharide. [Methods]S. nudus polysaccharide was extracted by ultrasonic water extraction,with the marine S. nudus as a raw material from Sanya City,Hainan Province,by single factor variable method,to find the optimal extraction conditions including ultrasonic power,solid-liquid ratio,ultrasonic extraction temperature,ultrasonic extraction time,ultrasonic extraction times and lye concentration. The absorbance of the polysaccharide was determined by an ultraviolet spectrophotometer,and polysaccharide yield were calculated. The antioxidant activity of scavenging hydroxyl and DPPH radicals was measured at different concentrations. [Results]The optimal extraction conditions for S. nudus polysaccharide were as follows： solid-liquid ratio at 1∶11 mg/ml,extraction temperature at 60 ℃,three times of ultrasonic extraction,ultrasonic power of 960 W,extraction time of 1. 5 h,and lye concentration of 5%,under which the polysaccharide yield was 3. 21%. The scavenging rates of hydroxyl radical and DPPH radical were 12. 58% at the concentration of 0. 20 mg/ml. Moreover,the scavenging rates increased significantly with the increase of concentration. [Conclusions] This method is a new trial with satisfactory results.

Effects of Dietary Carbohydrate-lipid Ratio on Growth, Body Composition and Digestive Enzyme Activities of Juvenile Peanut Worm,Sipunculus nudus

[Objective] This study was conducted to investigate the effects of dietary carbohydrate-lipid( C / L) ratios on growth performance,body composition and digestive enzyme activities of juvenile peanut worm. [Methods]Juvenile peanut worm with average body weight of( 16. 77 ± 0. 40) mg were fed with five isonitrogenous and isoenergetic diets formulated to contain different carbohydrate / lipid( C / L) ratios( 0. 68,1. 02,1. 62,2. 61 or 4. 35) for 8 weeks. [Results] The dietary C / L ratios had no significant effects on survival of juvenile peanut worm( P 】 0. 05). With the increasing of dietary C / L ratios,weight growth rate( WGR)and specific growth rate( SGR) increased when dietary C / L ratios were between 0. 68 and 2. 61,and then decreased significantly with dietary C / L ratio further increased. When the dietary C / L ratio was 2. 61( carbohydrate level was 20. 64%,lipid level was 7. 92%) both WGR and SGR produced the maximum value,they were 451. 78 ± 16. 85% and 3. 41 ± 0. 06 % / d,respectively. The dietary C / L ratios had significant effects on body moisture,body protein content and body lipid content( P 【 0. 05),but no significant effects on body ash content of juvenile peanut worm( P 】 0. 05). Different C / L ratios had significant effects on amylase activity and lipases activity of juvenile peanut worm( P 【 0. 05),but no significant effects on protease activity( P 】 0. 05). [Conclusion]The regression model analysis showed that the most suitable dietary C / L ratio which can make juvenile peanut worm acquire the best weight growth rate is 2. 42.

Effects of Dietary Carbohydrate Sources on Daily Weight Gain and Digestive Enzyme Activities of Juvenile Peanut Worm(Sipunculus nudus)

In the study,glucose,sucrose,dextrin,tapioca starch,potato starch,corn starch and gelatinized corn starch were selected to make the diets with same nitrogen and lipid,and Juvenile peanut worms( Sipunculus nudus) were fed with the diets came from different carbohydrate sources,effects of diets with different carbohydrate sources on daily weight gain and digestive enzyme activities of S. nudus were studied. Results showed that diets with different carbohydrate sources had significant influences on daily weight gain and digestive enzyme activities of S. nudus( P < 0. 05). Daily weight gain in gelatinized corn starch group was significantly higher than that in other groups( P < 0. 05); daily weight gain in glucose group was significantly lower than that in other groups( P < 0. 05); daily weight gain in the three ungelatinized starch groups was significantly higher than that in glucose,sucrose and dextrin groups( P < 0. 05). Analysis of digestive enzyme activities showed that dietary carbohydrate sources had significant influences on digestive enzyme activities of S. nudus( P < 0. 05). Protease activities and amylase activities of S. nudus in sucrose group were the highest,which were significantly higher than that in the other groups( P < 0. 05); lipase activities of S. nudus in glucose group were the lowest,which were significantly lower than that in other groups( P < 0. 05). In conclusion,growth-promoting effects of macromolecules carbohydrates( starch) were better than that of disaccharide( sucrose) and monosaccharide( glucose),which of gelatinized starch were better than that of ungelatinized starch.

不同加工方式沙虫干品的脂肪酸组成比较

为研究不同加工方式下方格星虫(Sipunculus nudus)脂肪酸组成特征,采用气相色谱仪检测水煮烘干和暴晒干燥两种加工方式下方格星虫体壁脂肪酸种类和含量。结果显示,水煮干燥和暴晒加工方格星虫体壁中分别检测出21种、20种脂肪酸,分别包含12种、11种不饱和脂肪酸(UFA),两种加工方式具有相同的饱和脂肪酸(SFA)种类(9种)。水煮加工的饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)含量分别为7.97、1.21和5.56 mg/kg,而暴晒加工的SFA、MUFA、PUFA分别为5.84、0.34和2.47 mg/kg。水煮加工方格星虫的体壁饱和脂肪酸含量显著高于暴晒加工(P<0.05)。两种加工方式方格星虫体壁中的不饱和脂肪酸占总脂肪酸的45.96%和32.98%,而SFA∶MUFA∶PUFA比值分别是1∶0.15∶0.7和1∶0.06∶0.42。两种加工方式样品中的十一碳酸、油酸和亚油酸分别是SFA、MUFA、PUFA含量最高的。在单不饱和脂肪酸中,水煮加工样品中的十八碳一烯酸的含量显著高于暴晒加工(P<0.05);在多不饱和脂肪酸中,水煮烘干样品中的9,12-十八碳二烯酸、6,9,12-十八碳三烯酸、8,11,14-二十碳三烯酸、5,8,11,14,17-二十碳五烯酸显著高于暴晒加工(P<0.05)。综合分析表明,不同加工方式会影响方格星虫干品中的脂肪酸含量,水煮干燥加工方式的脂肪酸保留率高于直接暴晒方式。