发酵时间对馒头品质及面筋蛋白结构的影响

Effects of Fermentation Time on Steamed Bread Quality and Gluten Structure

利用体积仪、质构仪和傅里叶变换红外光谱分别测定馒头比容、质构特性与面筋蛋白二级结构,探究发酵时间对馒头品质及面筋蛋白结构的影响。结果表明:馒头中醇溶蛋白与麦谷蛋白中β-折叠含量均为最高。随着发酵时间的不断延长,醇溶蛋白中β-折叠、α-螺旋相对含量无显著性变化,无规则卷曲逐渐减少,而β-转角则逐渐增加;羟基吸收带逐渐增强,醇溶蛋白的水合作用增强。麦谷蛋白中α-螺旋与无规则卷曲相对含量变化不大,β-折叠相对含量先上升后下降,而β-转角相对含量则是先下降后上升;羟基带强度逐渐减弱;当发酵时间延长到80 min时,麦谷蛋白红外光谱位于1 082 cm^(-1)与1 155 cm^(-1)处的峰消失,可能是蛋白质环状结构的C—C振动减弱。

The specific volume and texture properties of steamed bread and the secondary structure of gluten were determined by a volume meter,a texture analyzer and Fourier transform infrared（FTIR）spectroscopy,respectively.The effects of fermentation time on bread quality and gluten protein structure were investigated.The results showed thatβ-sheet was the dominant secondary structure for both the glutenin and gliadin in steamed bread.The contents ofβ-sheet andα-helix in the gliadin did not significantly change with fermentation time,whereas random coil gradually decreased andβ-turn increased;the intensity of the hydroxyl absorption band was gradually increased,and the hydration of the gliadin was enhanced.For the glutenin,the contents ofα-helix and random coil changed little;β-sheet content increased first and then decreased while the opposite was observed forβ-turn.The intensity of the hydroxyl absorption band gradually declined.The peaks at 1 082 cm-1 and 1 155 cm-1in the FTIR spectrum of the glutenin disappeared at 80 min of fermentation,which may be attributed to the weakened C–C vibration of the protein ring structure