黄芪下脚料粗多糖提取工艺优化及对鲤鱼非特异性免疫指标的影响

Optimization of extraction process of crude polysaccharide from Astragalus offcuts and its effect on non-specific immunity indexes of carp

为了提高黄芪下脚料中粗多糖的提取率并明确黄芪下脚料中粗多糖对鲤鱼非特异性免疫指标的影响,试验采用单因素试验及响应面法优化黄芪下脚料中粗多糖的提取工艺;将100尾健康且体重接近的鲤鱼随机均分为空白对照组、中药对照组、低剂量组、中剂量组和高剂量组,空白对照组饲喂基础饲料,中药对照组饲喂添加0.1%黄芪粗多糖的基础饲料,低、中、高剂量组分别饲喂添加0.1%、0.2%、0.4%黄芪下脚料粗多糖的基础饲料,连续饲喂42 d,取鲤鱼尾静脉血液,测定溶菌酶(LZM)、碱性磷酸酶(AKP)和超氧化物歧化酶(SOD)活性。结果表明:在提取温度为93℃、提取时间为2.8 h、料液比为1∶30条件下黄芪下脚料粗多糖最大提取率为7.67%。中剂量组LZM、SOD活性都显著高于空白对照组(P<0.05);低剂量组AKP活性显著高于空白对照组和中药对照组(P<0.05);高剂量组LZM活性显著低于中剂量组(P<0.05),SOD活性显著低于低剂量组和中剂量组(P<0.05),AKP活性低于低剂量组和中剂量组,但差异不显著(P>0.05)。说明通过响应面法优化黄芪下脚料粗多糖提取工艺后,可以从黄芪下脚料中提取到较高含量的粗多糖,且在基础饲料中添加0.1%~0.2%黄芪下脚料粗多糖可以明显提高鲤鱼的免疫力。

In order to improve the extraction rate of crude polysaccharides from Astragalus offcuts,in the experiment,the extraction process of crude polysaccharide from Astragalus offcuts was optimized using one-way test and response surface method.One hundred healthy carp with close body weight were randomly divided into blank control group,Chinese medicine control group,low dose group,middle dose group and high dose group.The blank control group was fed with basal feed;the Chinese medicine control group was fed with basal feed containing 0.1% crude polysaccharide from Astragalus offcuts;the low-dose group was fed with basal feed containing 0.1% crude polysaccharide from Astragalus offcuts;the medium-dose group was fed with basal feed containing 0.2% crude polysaccharide from Astragalus offcuts;the high-dose group was fed with basal feed containing 0.4% crude polysaccharide from Astragalus offcuts;and the dietary supplementation period lasted 42 days.At the end of the experimental period,blood was taken from the tail vein of carp,and the activities of lysozyme(LZM),alkaline phosphatase(AKP) and superoxide dismutase(SOD) were determined.The results showed that the maximum extraction rate of crude polysaccharides from Astragalus offcuts was 7.67% under the conditions of extraction temperature of 93 ℃,extraction time of 2.8 h,and material-liquid ratio of 1∶30(g/mL).The LZM,AKP and SOD activities of the low-dose and medium-dose groups with 0.1% and 0.2% of crude polysaccharide from Astragalus offcuts were significantly higher than those of the blank control group(P<0.05);the medium-dose group had the greatest LZM and SOD activities.AKP activity was significantly higher(P<0.05) in the low dose group than those in the blank and Chinese medicine control groups.The LZM activity in the high-dose group was significantly lower than that in the medium-dose group(P<0.05);the SOD activity was significantly lower than that in the low-dose and medium-dose groups(P<0.05);and the AKP activity was lower than that in the low-dose and medium-dose groups,but the difference was not significant(P>0.05).The results suggested that a higher content of crude polysaccharides could be extracted from Astragalus offcuts after optimizing the extraction process of crude polysaccharides from Astragalus offcuts by response surface methodology;and the addition of 0.1%-0.2% crude polysaccharides from Astragalus offcuts in the basal feeds could obviously improve the immune ability of carp.