黑白两种糯米米糠可溶性膳食纤维的特性及对淀粉体外消化吸收的影响

Characteristics of soluble dietary fiber of black and white rice bran and its effect on digestion and absorption of starch in vitro

以黑糯米米糠和白糯米米糠2种米糠为原料,从中提取可溶性膳食纤维(soluble dietary fiber,SDF),比较两者的理化性质和生物活性,通过模拟葡萄糖体外消化和吸收试验,探讨SDF降低餐后血糖水平的作用机制。结果表明,黑糯米米糠和白糯米米糠的红外和紫外光谱特征显示两者均具有多糖的典型特征;黑糯米米糠SDF的酚含量、粘度、相对分子质量、聚集颗粒的组装、表面孔隙率和孔径、抗氧化性等均有利于其对葡萄糖的吸附和抑制葡萄糖的扩散,效果优于白糯米米糠SDF;而白糯米米糠SDF的溶解度、抑制淀粉的消化和α-淀粉酶活力的能力却大于黑糯米米糠SDF。上述结果说明,黑糯米米糠SDF具备更好的营养价值和生物活性。

The physical and chemical properties and bioactivities of the two kinds of SDF from black and white glutinous rice bran were studied to explore the possible role of SDF in lowering the blood glucose levels after the meal by digesting and absorbing glucose in vitro.The results showed that two samples had the typical characteristic of polysaccharide based on analyzing the infrared and ultraviolet spectrum.The contents of phenol,viscosity,molecular weight,assembly of aggregated particles,porosity of surface and pore size,oxidation resistance of SDF from black glutinous rice bran was favorable for absorbing glucose and inhibiting glucose diffusion,better than that of SDF from white glutinous rice bran.But the dissolution rate,the ability of inhibiting starch digestion andα-amylase activity of SDF from white glutinous rice bran was higher than that of SDF from black glutinous rice bran.It is indicated that the nutritional value and bioactivity of SDF from black glutinous rice bran is better than that from white glutinous rice bran.