谷朊粉对高含量荞麦面团的影响及其作用机理

本文全面研究了不同添加量谷朊粉(5%、10%和15%)对高含量(50%小麦粉替代率)荞麦面团流变学特性及馒头品质的影响,并以添加10%谷朊粉的混合面团和参照组(纯小麦粉)面团为基础,通过扫描电镜,红外光谱及分析面团中的化学作用力等分析手段,进一步探讨了谷朊粉对改善混合面团流变学性质及馒头品质方面的作用机理。结果表明,添加10%的谷朊粉能够增加荞麦-小麦混合面团中二硫键的含量,改变面团中的化学作用力(离子键、氢键含量和疏水作用力),进而改变面团中面筋蛋白的构象,改善面团的微观结构,从而改善混合粉的糊化特性及面团的粉质和拉伸特性,提高馒头的比容和弹性,改善馒头芯的孔隙结构,但仍达不到参照组馒头的品质,表明添加高含量荞麦全粉不仅仅是稀释面筋蛋白。

Effect of Wheat Gluten Content on Buckwheat Dough and its Mechanism of Action

The effect of different wheat gluten content (5%, 10%, and 15%) on the rheological properties of high content (50% wheat flour replacement rate) buckwheat dough and the quality of Chinese steamed bread (CSB) were comprehensively studied in this paper. Based on mixed dough with 10% wheat gluten and the reference (pure wheat flour) dough, the mechanism of the action of wheat gluten on the improvement of the rheological properties of mixed dough and CSB quality was further studied using scanning electron microscopy and Fourier transform infrared (FT-IR) spectroscopy as well as by analyzing chemical interactions in the dough. The results indicated that the addition of 10% wheat gluten increased the disulfide bond content of buckwheat-wheat dough, changed the chemical interactions (ionic bond and hydrogen bond content and hydrophobic forces), changed the gluten protein conformation, and improved the microstructure of mixed dough. Consequently, the pasting properties of mixed flour, the farinograph and extensograph properties of dough, the specific volume and springiness of CSB, and the pore structure of CSB core were improved, but the quality was still not equal to the quality of pure wheat steamed bread, suggesting that the addition of high levels of buckwheat flour does not merely dilute the gluten protein.