黄秋葵多糖缓冻协同微波提取工艺优化及其降血糖作用

本文采用缓冻协同微波辅助提取手段，通过单因素实验，确定合适的因素，采用响应面优化方法对黄秋葵多糖提取工艺条件进行优化；采用对硝基苯基-α-D-吡喃葡萄糖苷（pNPG）法测定黄秋葵多糖对α-葡萄糖苷酶活性的影响，通过小鼠实验，测定黄秋葵多糖对肾上腺素引起高血糖小鼠血糖水平的影响，从而探索黄秋葵多糖的降血糖作用。结果表明:通过响应面优化提取条件，确定黄秋葵多糖的最佳提取工艺条件是缓冻时间16 h，液料比40:1（mL/g），浸提时间2.2 h；浸提温度65℃，微波功率310 W，在此条件下，黄秋葵多糖的得率可达到17.17%，明显高于相对单一的提取工艺。黄秋葵多糖能够明显抑制α-葡萄糖苷酶的活性，在10 mg·mL-1剂量下抑制率达68.26%；且极显著降低肾上腺素引起高血糖小鼠的血糖水平（P<0.01）。缓冻协同微波处理能够显著提高黄秋葵多糖的得率，黄秋葵多糖具有良好的降血糖作用，具备开发成为预防和治疗糖尿病的市场应用与开发前景。

Optimization of Polysaccharide from Okra by Slowfreezing-Microwave Assisted Extraction Method and Its Hypoglycemic Activity

Slow freezing-microwave assisted extraction optimized by single factor experiment and response surface methodology was implemented to extract polysacchrides from Okra.To explore the hypoglycemic effect of okra polysaccharides,the inhibitory effects on the activities ofα-glycosidase were studied by the colorimetry of pNPG,the effects on blood glucose were studied in adrenaline-induced hyperglycemia model mices.Results showed that the optimal conditions were slow freezing time 16 h,liquid-solid ratio 40∶1(mL/g),extracting time 2.2 h,extracting temperature 65℃,microwave power 310 W.Under these conditions,the extraction rate of polysaccharide was 17.17%,which was significantly higher than a single extraction process.The polysaccharides from Okra could significantly inhibited the activity ofα-glucosidase,the inhibition rate was 68.26%at 10 mg·mL-1;and significantly reduced the blood glucose level of adrenaline-induced hyperglycemia mices(P<0.01).The extraction rate of okra polysaccharides was improved by slowfreezing-microwave assisted extraction method.Okra polysaccharides had better potential for the hypoglycemic effect,and might be developed to prevent and treat diabetes.