将新鲜米糠贮藏不同时间后脱脂制备米糠谷蛋白,研究米糠酸败对米糠谷蛋白结构的影响。结果表明,随着新鲜米糠贮藏时间的延长,米糠谷蛋白羰基、二硫键含量增加,游离巯基含量下降,表明米糠酸败导致米糠谷蛋白氧化。随着新鲜米糠贮藏时间的延长,米糠谷蛋白二级结构中a-螺旋和β-折叠含量下降,β-转角和无规卷曲含量上升,Zeta电位绝对值、表面疏水性和内源荧光强度下降,内源荧光最大吸收波长发生蓝移,并且伴随着蛋白质聚集体的出现,表明米糠酸败使得米糠谷蛋白结构发生变化,逐渐形成氧化聚集体。
Fresh rice bran which stored in a condition for different period was used as material to prepare rice bran glutelin after defatting, and effects of rice bran rancidity on the structure properties of rice bran glutelin were in- vestigated. The results indicated that as storage time of fresh rice bran increased, rice bran glutelin carbonyl and disul- fide content increased, and free sulphydryl content of rice bran glutelin decreased, which indicated that storage of rice bran led to oxidation of rice bran glutelin. As storage time of fresh rice bran increased, contents of a - helix and β- sheet of rice bran glutelin secondary structure decreased, contents of β - turn and random coil increased, absolute val- ue of zeta potential, surface hydrophobicity, and intrinsic fluorescence intensity of rice bran glutelin decreased, and blue shift of the maximum emission wavelength were accompanied by formation of protein aggregates. The results indi- cated that structural properties of rice bran glutelin changed which induced by rice bran rancidity, and formed oxida- tive aggregates of rice bran glutelin.