Wang Jinshui, Yue Yuanyuan, Liu Tiantian, Zhang Bin, Wang Zhenlei, Zhang Changfu
College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, China.
Interdiscip Sci. 2017 Jun;9(2):247-253. doi: 10.1007/s12539-016-0206-3. Epub 2016 Dec 24.
Wheat sourdough was prepared by fermentation with Lactobacillus plantarum M616 and yeast in the present study. The change in secondary structure of glutenin macropolymer (GMP) in wheat sourdough fermentation for 4 and 12 h was determined using Fourier transform infrared spectroscopy, and then the resultant spectra were Fourier self-deconvoluted of the amide I band in the region from 1600 to 1700 cm. Significant different spectra especially in the amide I band for GMP from sourdough fermented with L. plantarum M616 (SL) and with L. plantarum M616 and yeast (SLY) were found in respect of control dough (CK), dough with acids (SA), and sourdough fermented with yeast (SY) at 4 and 12 h of fermentation. The loss of α-helix structure in SL, SLY, and SA samples was noticed during fermentation. Compared with CK and SY, SL, SLY, and SA samples showed significant decrease (p < 0.05) in the relative areas of α-helix at the same stage of fermentation. In addition, β-turns in SL sourdough decrease, and the relative areas of random coil increase significantly (p < 0.05). These changes in the secondary structure mean that the flexibility of glutenin macropolymer in sourdough increases and it makes GMP degradation easier during fermentation. The modified secondary structure of GMP makes more sensitive to proteolysis by means of cereal enzymes.
在本研究中，用植物乳杆菌M616和酵母发酵制备小麦酸面团。使用傅里叶变换红外光谱法测定小麦酸面团发酵4小时和12小时过程中麦谷蛋白大聚合体（GMP）二级结构的变化，然后对所得光谱在1600至1700cm区域的酰胺I带进行傅里叶自去卷积。在发酵4小时和12小时时，发现与对照面团（CK）、加酸面团（SA）和酵母发酵酸面团（SY）相比，用植物乳杆菌M616发酵的酸面团（SL）以及用植物乳杆菌M616和酵母发酵的酸面团（SLY）的GMP光谱，尤其是酰胺I带存在显著差异。在发酵过程中，观察到SL、SLY和SA样品中α-螺旋结构的损失。与CK和SY相比，SL、SLY和SA样品在相同发酵阶段的α-螺旋相对面积显著降低（p<0.05）。此外，SL酸面团中的β-转角减少，无规卷曲的相对面积显著增加（p<0.05）。二级结构的这些变化意味着酸面团中麦谷蛋白大聚合体的柔韧性增加，并且使得发酵过程中GMP降解更容易。GMP二级结构的改变使其对谷物酶的蛋白水解作用更敏感。
