响应面法优化提取大果山楂果渣果胶及其降糖活性研究

Optimization of extraction of pectin from Malus doumeri by response surface methodology and its hypoglycemic activity

目的建立一种高效的大果山楂果渣果胶提取工艺,并对果胶的初步特性及降糖活性进行研究。方法通过响应面分析法对大果山楂果渣果胶提取工艺进行优化,考察因素包括酶用量、液料比和提取时间等。进一步对其半乳糖醛酸含量、酯化度指标进行分析,并借助α-葡萄糖苷酶抑制实验及胰岛素抵抗细胞实验,探讨大果山楂果渣果胶潜在的降糖活性。结果优化果胶提取工艺参数为:纤维素酶浓度3.4%,液料比7:1(mL:g),提取时间3.5 h,此条件下果胶得率最高,达到13.22%。除蛋白果胶的半乳糖醛酸含量为67.83%,酯化度为45.24%。体外活性实验显示果胶对α-葡萄糖苷酶抑制率达到89.41%,同时可以显著促进地塞米松(3.75μmol/L)和胰岛素(0.01μmol/L)联合诱导的IR-HepG2模型葡萄糖消耗。结论在所述提取工艺条件下,大果山楂的果胶得率最优,所提取的果胶为低酯果胶,表现出良好的降糖功效。

Objective To establish the extraction process of pectin from Malus doumeri fruit residue,and carry out research on its preliminary characterization and hypoglycemic activity.Methods Response surface analysis was carried out using the factors of enzyme dosage,liquid-to-feed ratio and extraction time in order to optimize the extraction process of Malus doumeri fruit residue pectin.Meanwhile,an in-depth analysis of its physicochemical properties was carried out,and its potential hypoglycemic activity was explored usingα-glucosidase inhibition assay and insulin resistance cell assay.Results The optimal extraction process conditions for Malus doumeri fruit residue pectin were determined to be cellulase concentration of 3.4%,liquid to material ratio of 7:1(mL:g),and extraction time of 3.5 hours,which sulted in a maximum pectin yield of(13.22%).Analysis of the physicochemical properties of the pectin showed that the galacturonic acid content was 67.83%,and the degree of esterification was 45.24%.Pectin exhibited a highα-glucosidase inhibition rate of 89.41%,increasing glucose consumption in the established IR-HepG2 model under the combined action of dexamethasone(3.75μmol/L)and insulin(0.01μmol/L)within 48 h.Conclusion Under this extraction process,Malus doumeri fruit residue pectin has the highest yield,and the extracted pectin is low ester pectin with good hypoglycemic activity.