挤压加工对米糠主要营养成分影响的研究

Rice Bran:Extrusion Processing and Nutrition

挤压机瞬时、高温、高压、高剪切的加工特点使其具有生化反应器的功能。对挤压改性加工后的米糠粉的主要营养成分变化情况进行了测试,结果表明:挤压加工后的米糠SDF含量增加了7.26%;米糠蛋白降解,蛋白质分子量整体降低;淀粉含量减少,部分淀粉降解为糊精,糊化度大幅度增大,直链淀粉含量增加;在240d的时间里FFA值仅增加了0.6%,很好地解决了米糠稳定化问题;矿物质含量几乎不变;米糠的组织结构疏松,均匀,其融合及组织化程度均有提高。挤压后的米糠主要营养成分均发生了有益的变化,更利于人体的消化吸收和利用。

Extrusion, with its characteristics of short time, high temperature, high pressure, and strong shearing, plays a role like a biochemical reactor. The main nutrient contents of the rice bran denatured by extrusion were tested. The following are results ： The content of soluble dietary fiber （SDF） of the extruded rice bran increases to 7. 26%. The rice bran protein exhibits degradation and the protein molecular weights declines. The starch content decreases a lot and partial starch is decomposed into dextrin; the starch exhibits obvious gelatinization and the amylose content increases. The FFA just increases by 0.6% during 240d, so the problem of rice bran stabilization is solved well. There is almost no change in the mineral contents; furthermore, the rice bran tissue and texture become soft, even and loose. These changes taken place after the rice bran extrusion are beneficial for body digestion and rice bran utilization.