摘要
为开发利用蛋白桑叶中蛋白质资源,对其蛋白质提取工艺及酶解物体外降血糖活性进行研究。本研究以蛋白桑叶为原料,采用超声辅助碱提酸沉法提取蛋白桑叶蛋白质。通过单因素实验和响应面法优化提取工艺,以α-葡萄糖苷酶抑制率为评价指标,分析不同蛋白桑叶蛋白酶解产物体外降血糖活性。结果表明,蛋白桑叶中蛋白质的最佳提取工艺为:氢氧化钠浓度0.125 mol/L、提取温度40℃、提取时间40 min和液料比37:1 mL/g。在此优化条件下,得到蛋白质提取率实际值为49.59%±0.45%,所得蛋白质等电点为pH3.5,吸水性为6.49±0.49 g/g,吸油性为2.59±0.06 g/g,乳化活性为7.40±0.17 m^(2)/g,乳化稳定性为72.48%±3.03%。研究考察了蛋白桑叶蛋白质的复合蛋白酶酶解物、风味蛋白酶酶解物、碱性蛋白酶酶解物、胰蛋白酶酶解物、中性蛋白酶酶解物、木瓜蛋白酶酶解物体外降血糖活性,其中中性蛋白酶酶解物对α-葡萄糖苷酶抑制效果最佳,其IC_(50)=3.52 mg/mL。本研究认为,此蛋白桑叶蛋白质提取工艺稳定,中性蛋白酶解肽具有较高的体外降血糖活性,为进一步开发蛋白桑叶蛋白质及其多肽资源提供参考。
The protein extraction process of protein mulberry leaves and hypoglycemic activity in vitro of the enzymatic hydrolysates were studied aiming at further developing and utilizing protein resources in mulberry leaves.Protein mulberry leaf protein(PMLP)was extracted from protein mulberry leaves through the ultrasound-aided alkaline extraction and acid precipitation.The single factor experiments and response surface methodology were applied to optimize the extraction process of PMLP.The inhibitory rate ofα-glucosidase was used as the evaluation index to analyze the hypoglycemic activity in vitro of different PMLP enzymatic hydrolysates.The results showed that the optimum extraction conditions of PMLP were as follows:NaOH concentration was 0.125 mol/L,extraction temperature was 40℃,extraction time was 40 min and liquid-solid ratio was 37:1 mL/g.Under these conditions,the actual extraction rate of PMLP reached 49.59%±0.45%,the obtained protein isoelectric point was pH3.5,the water holding capacity was 6.49±0.49 g/g,the oil holding capacity was 2.59±0.06 g/g,the emulsifying activity was 7.40±0.17 m2/g,and the emulsion stability was 72.48%±3.03%.The hypoglycemic activity in vitro of the PMLP enzymatic hydrolysates digested by compound protease hydrolysate,flavor protease hydrolysate,alkaline protease hydrolysate,trypsin hydrolysate,neutral protease hydrolysate and papain was investigated. Among the enzyme species examined,the neutral protease hydrolysate of PMLP demonstrated the highest inhibitory effect on α-glucosidase with IC_(50)=3.52 mg/mL. According to results of the study, the extraction process of PMLP was stable, and the PMLP enzymatic hydrolysate digested by neutral protease had strong hypoglycemic activity in vitro, which would provide a reference for the further development of protein mulberry leaf protein and peptides resources.
作者
曹天丽
郝巨辉
李卫东
CAO Tianli;HAO Juhui;LI Weidong(School of Chinese Materia Medica,Beijing University of Chinese Medicine,Beijing 102488,China)
出处
《食品工业科技》
CAS
北大核心
2023年第12期232-241,共10页
Science and Technology of Food Industry
关键词
桑
蛋白桑
桑叶
蛋白质提取
酶解
α-葡萄糖苷酶抑制率
降血糖活性
Morus alba L.
protein mulberry
mulberry leaves
protein extraction
enzymolysis
α-glucosidase inhibition rate
hypoglycemic activity
