金铃子果皮多糖超声辅助提取工艺优化及其抗氧化和降糖活性研究

康桥; 孙越; 刘梦瑶; 赵保龙; 李贺贺; 王柏文; 赵东瑞; 孙宝国; 孙金沅

doi:10.13386/j.issn1002-0306.2023120028

金铃子果皮多糖超声辅助提取工艺优化及其抗氧化和降糖活性研究

Optimization of the Ultrasonic-assisted Extraction Process of Polysaccharides from the Peels of Wild Bitter Melon (Momordica charantia Linn. Var. Abbreviata Ser.) and a Preliminary Study on Their Antioxidant and Hypoglycemic Activities

摘要

摘要: 本研究拟探究金铃子多糖的提取工艺、理化性质、抗氧化和降糖活性。以新鲜金铃子果实的果皮为原料，基于单因素实验结果，对超声辅助提取（UAE）过程中的液料比、超声时间和超声功率进行Box-Behnken响应面优化，并以最佳条件进行超声萃取。分级醇沉得到两个多糖组分WBP50和WBP75，对其理化性质、体外抗氧化和降血糖能力进行评价。结果表明：在液料比16 mL/g，超声时间16 min，超声功率312 W的条件下，金铃子粗多糖实际得率8.33%±0.13%；WBP50和WBP75的总糖、蛋白质、总酚、总黄酮和糖醛酸含量分别为76.73%/73.38%、4.78%/0.35%、0.36%/0.25%、2.06%/0.86%和72.85%/49.58%；WBP50和WBP75平均分子量分别为27.59 kDa和23.20 kDa，主要由半乳糖醛酸、半乳糖、鼠李糖、阿拉伯糖、葡萄糖组成；两种金铃子多糖对DPPH、ABTS⁺和羟基自由基的清除能力分别为11.28/11.40 μg Trolox/mg、40.87/44.42 μg Trolox/mg和52.47/99.89 U/mg。在降血糖方面，WBP50和WBP75都具有一定的α-淀粉酶活性抑制能力和较强的α-葡萄糖苷酶活性抑制能力，在浓度750 μg/mL时对α-葡萄糖苷酶的抑制率可高达93.34%±1.11%和79.04%±0.76%。超声辅助提取金铃子多糖的工艺具有省时方便、高效率耗能低的优点，且所提取的金铃子多糖具有天然的抗氧降糖功能活性，本研究为未来金铃子多糖的结构解析及功能活性作用机制研究奠定基础，为金铃子多糖的降糖产品开发及高值化利用提供理论参考。

Abstract: This study intends to explore the extraction process, physical and chemical properties, antioxidant and hypoglycemic activities of polysaccharides from wild bitter melon (WBM). Using the peel of fresh WBM fruit as raw material, based on the single factor experimental results, the liquid-to-material ratio, ultrasonic time and ultrasonic power in the ultrasound-assisted extraction (UAE) process were optimized by Box-Behnken response surface. Two polysaccharide components of WBP50 and WBP75 were obtained through UAE of the optimal conditions and gradient alcohol precipitation, and their physical and chemical properties, in vitro antioxidant and hypoglycemic abilities were evaluated. The results showed that: under the conditions of liquid-to-material ratio of 16 mL/g, ultrasonic time of 16 min, and ultrasonic power of 312 W, the actual yield of crude WBM polysaccharide (WBP) was 8.33%±0.13%. The total sugar, protein, total phenols, total flavonoids, and uronic acid contents of WBP50 and WBP75 were 76.73%/73.38%, 4.78%/0.35%, 0.36%/0.25%, 2.06%/0.86% and 72.85%/49.58%, respectively. The average molecular weights were 27.59 kDa and 23.20 kDa, respectively. WBPs were mainly composed of galacturonic acid, galactose, rhamnose, arabinose, and glucose. The DPPH, ABTS⁺ and hydroxyl radicals scavenging abilities of WBP50 and WBP75 were 11.28/11.40 μg Trolox/mg, 40.87/44.42 μg Trolox/mg, and 52.47/99.89 U/mg, respectively. Regarding hypoglycemic ability, both WBPs had certain α-amylase inhibitory ability and strong α-glucosidase inhibitory ability. The α-glucosidase inhibition rate of WBP50 and WBP75 reached 93.34%±1.11% and 79.04%±0.76% at a concentration of 750 μg/mL. The UAE of WBP has the advantages of time saving, convenience, high efficiency and low energy consumption, and the extracted WBPs have natural antioxidant and hypoglycemic functional activities. This study lays the foundation for future structural analysis and functional mechanism research of WBPs and provides theoretical references for developing hypoglycemic products and high-value utilization of WBPs.