小米糠膳食纤维结构分析及体外抑制α-葡萄糖苷酶活性研究

发布时间：2018-01-11 14:27

  本文关键词：小米糠膳食纤维结构分析及体外抑制α-葡萄糖苷酶活性研究　出处：《黑龙江八一农垦大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 水溶性膳食纤维 气爆 改性 结构分析 α-葡萄糖苷酶 抑制作用

【摘要】：为了研究小米糠水溶性膳食纤维(Soluble dietary fiber,SDF)的改性方法、结构特征及对α-葡萄糖苷酶活性的体外抑制作用。本文以红谷小米糠为实验材料,对其进行气爆预处理,利用超声-微波协同法和酶法对气爆预处理的小米糠膳食纤维进行改性,以提高小米糠SDF的得率,并利用响应面法优化其工艺条件,同时借助扫描电镜、凝胶色谱-示差-多角度激光光散射(GPC-RI-MALS)、X射线衍射、红外光谱和离子色谱分析方法对改性前后小米糠膳食纤维的结构进行研究。通过建立α-葡萄糖苷酶抑制剂模型,研究脱脂小米糠SDF和改性小米糠SDF对α-葡萄糖苷酶活性的体外抑制作用。结果表明:(1)气爆条件设定为压力1.0 MPa、时间90 s,超声-微波协同法改性的最优工艺参数为微波功率535 W、料液比1:50(g/m L)、超声-微波协同时间57 min,SDF含量达到10.841%。酶法改性的最优工艺参数为酶添加量5.94%,温度56℃,p H4.65,时间3 h,SDF含量为10.507%。(2)扫描电镜结果显示,改性小米糠SDF的颗粒表面变得粗糙,疏松多孔,由小颗粒聚集而成。GPC-RI-MALS分析表明,改性前后小米糠SDF的分子量分布较广,从重均分子量角度分析,改性小米糠SDF的分子量变小。X射线衍射分析表明,改性小米糠不溶性膳食纤维(Insoluble dietary fiber,IDF)的结晶度升高,表明改性小米糠IDF中非结晶区有部分降解,并且转化为SDF。红外光谱分析表明,改性小米糠SDF和IDF的化学官能团变化不大,并且有明显的糖类特征吸收峰。离子色谱结果显示,改性前后小米糠SDF都含有阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖、果糖,但两者在含量上存在差异。(3)小米糠SDF对α-葡萄糖苷酶活性的抑制试验表明,脱脂小米糠SDF对α-葡萄糖苷酶活性的抑制曲线方程为:y=26.36499×ln(x+15.62773),R2=0.90282,IC50值为2.934 mg/m L;改性小米糠SDF对α-葡萄糖苷酶活性的抑制曲线方程为:y=29.77759×ln(x+13.89089),R2=0.93047,IC50值为0.415 mg/m L。综上所述,超声-微波协同法相比于酶法更适合于小米糠膳食纤维的改性。本实验研究了改性前后小米糠膳食纤维的结构,确定了小米糠膳食纤维的超微结构、分子量分布、晶型、化学官能团组成、单糖组成及含量,对比分析了改性前后小米糠膳食纤维的结构变化。体外试验表明,改性前后小米糠SDF对α-葡萄糖苷酶活性均有抑制作用,其中改性小米糠SDF抑制α-葡萄糖苷酶活性的作用较强。
[Abstract]:In order to study the modification method of water soluble dietary fiber (Soluble dietary fiberberger SDF) from rice bran. Structure characteristics and inhibition of 伪-glucosidase activity in vitro. In this paper, red millet rice bran was used as the experimental material, which was pretreated by gas explosion. In order to improve the yield of rice bran SDF, the ultrasonic microwave synergy method and enzymatic method were used to modify the rice bran dietary fiber pretreated by gas explosion, and the reaction surface method was used to optimize the process conditions and the scanning electron microscope (SEM). Gel chromatography-differential and multi-angle laser light scattering (GPC-RI-MALSX) X-ray diffraction. The structure of rice bran dietary fiber before and after modification was studied by infrared spectroscopy and ion chromatography. A model of 伪 -glucosidase inhibitor was established. The inhibitory effects of defatted rice bran SDF and modified rice bran SDF on 伪 -glucosidase activity in vitro were studied. The optimum technological parameters of ultrasonic and microwave synergistic modification are microwave power 535W, material / liquid ratio 1: 50g / mL, ultrasonic / microwave synergistic time 57 min. The content of SDF reached 10.841.The optimum technological parameters of enzymatic modification were enzyme addition 5.94, temperature 56 鈩，

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