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草业学报 ›› 2024, Vol. 33 ›› Issue (6): 105-115.DOI: 10.11686/cyxb2023260

• 研究论文 • 上一篇    

红三叶多糖的酶提取方法及抗氧化活性研究

祁兆奔1(), 任晓艳1, 李怡彤1, 马金云2, 刘权1()   

  1. 1.兰州大学草地农业科技学院,草种创新与草地农业生态系统全国重点实验室,红三叶高值化开发利用创新创业示范基地,甘肃 兰州 730020
    2.和政县林草事业发展中心,甘肃 临夏 731200
  • 收稿日期:2023-07-25 修回日期:2023-09-11 出版日期:2024-06-20 发布日期:2024-03-20
  • 通讯作者: 刘权
  • 作者简介:E-mail: liuquan@lzu.edu.cn
    祁兆奔(1997-),男,甘肃定西人,在读硕士。E-mail: qzhaoben@163.com
  • 基金资助:
    国家自然科学基金“红三叶与黑麦草混播过程中的化学互作研究”(31971763);甘肃省科技特派员创新创业示范基地“红三叶高值化开发利用创新创业示范基地”(20CX9NA106);阿拉善盟应用技术研究与开发资金计划(AMYY2022-19);定西市科技计划(DX2023AZ07)

Enzyme extraction method and antioxidant activity of polysaccharides from red clover

Zhao-ben QI1(), Xiao-yan REN1, Yi-tong LI1, Jin-yun MA2, Quan LIU1()   

  1. 1.College of Pastoral Grassland Agriculture Science and Technology,State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,Innovation and Entrepreneurship Demonstration Base of Red Clover High-value Utilization,Lanzhou University,Lanzhou 730020,China
    2.Forestry and Grass Development Center,Hezheng County,Linxia 731200,China
  • Received:2023-07-25 Revised:2023-09-11 Online:2024-06-20 Published:2024-03-20
  • Contact: Quan LIU

摘要:

红三叶是全世界种植范围较广的多年生豆科牧草,资源丰富,其多糖成分具有良好的降血糖和抗氧化活性,具有高附加值开发与利用的前景。酶提取条件相对温和,有利于提高多糖活性。本研究考察了酶解时间、酶用量、酶比例、酶解温度4个因素对红三叶多糖提取的影响。利用正交试验对提取条件进行优化筛选,确定酶提取方法为:酶解时间90 min,酶用量1.0%,酶解温度60 ℃,酶比例为木瓜蛋白酶∶纤维素酶∶果胶酶7∶2∶2,红三叶粗多糖含量为8.85%。本研究比较了酶提取以及文献中超声和热水提取,3种方法所制备红三叶多糖的理化性质和抗氧化活性。3个多糖提取样品均具有抗氧化活性,对O2·-自由基的清除活性明显高于阳性对照抗坏血酸。不同多糖提取样品的分子量范围差异明显,以酶提取和热水提取较为集中。3种多糖样品均由8种单糖组成,其中葡萄糖(Glu)、半乳糖(Gal)和阿拉伯糖(Ara)摩尔占比相对较高,约占到单糖组分的3/4。但单糖比例差异较大,酶提取多糖中Glu摩尔百分比最高,是热水提取多糖的1.6倍,超声提取的1.4倍。

关键词: 红三叶, 多糖, 酶提取, 工艺优化, 抗氧化活性

Abstract:

Red clover (Trifolium pratense) is a resource-rich perennial leguminous forage species that is cultivated worldwide. Its polysaccharide components have good hypoglycemic and antioxidant properties, and have potential applications in the development of new, high-value products. The polysaccharides can be extracted using enzymes, and milder extraction conditions are conducive to retaining their beneficial properties. In this study, the effects of enzymatic hydrolysis time, enzyme dosage, enzyme ratio, and enzymatic hydrolysis temperature on the extraction of red clover polysaccharides were investigated. The extraction conditions were optimized and screened by orthogonal experiments. The results showed that the best enzyme extraction method was as follows: enzymatic hydrolysis time of 90 min, enzyme dosage of 1.0%, enzymatic hydrolysis temperature of 60℃, and enzyme ratio papain∶cellulase∶pectinase of 7∶2∶2. The crude polysaccharide content in red clover was 8.85%. We compared the enzyme extraction method with two other methods; ultrasonic extraction and hot water extraction. Red clover polysaccharides were extracted using all three methods, and their physical and chemical properties and antioxidant activity were compared. All three polysaccharide extracts showed antioxidant activity, with stronger abilities to scavenge O2·- free radicals than that of the positive control, vitamin C. The molecular weight ranges of polysaccharide samples prepared using the different extraction methods were significantly different, and the enzyme extract and hot water extract were more concentrated than the ultrasonic extract. The three polysaccharide samples were composed of eight types of monosaccharides, among which glucose, galactose, and arabinose had relatively high molar ratios, accounting for approximately 3/4 of the monosaccharide components. The proportions of monosaccharides varied widely among the samples, and the molar percentage of glucose was highest in the enzyme-extracted polysaccharides (1.6 times that in hot water-extracted polysaccharides and 1.4 times that in ultrasonically extracted polysaccharides).

Key words: red clover, polysaccharides, enzyme extraction, process optimization, antioxidant activity