青稞粉对小麦面筋蛋白网络结构的影响

Effects of Adding Highland Barley Flour on the Network Structure of Wheat Gluten

摘要:

该文探究了不同添加比例（10%、20%和50%）的青稞粉（Highland Barley Flour, HBF）对小麦面筋蛋白网络结构的影响。热机械学特性检测表明，随着青稞粉添加比例的增多，面团吸水率、形成时间和蛋白质弱化度（C2）显著升高（P<0.05），而淀粉糊化特性、淀粉的稳定性和淀粉的回生值都整体呈现下降的趋势，表明青稞粉对面团中的蛋白质弱化及淀粉的糊化特性有明显的影响。扫描电子显微镜和激光共聚焦显微镜结果显示，较高的添加比例会阻碍面筋蛋白和淀粉的相互作用，从而破坏面筋蛋白的网络结构。拉曼光谱和红外光谱结果显示，蛋白质的空间结构发生了改变，二硫键由相对稳定的扭-扭-扭结构向不稳定的反-扭-反结构转变。二硫键测定结果显示，对照组的二硫键含量最高（14.41 μmol/g），当添加50%青稞粉后，二硫键含量相比对照组降低了21.44%。综上所述，添加不同比例的青稞粉均会破坏小麦面筋蛋白的稳定性及空间结构。该研究可为开发青稞蛋糕提供理论依据和实践参考。

Abstract:

Different proportions (10%, 20% and 50%) of highland barley flour (HBF) were added to wheat dough to clarify the effect of HBF proportion on the network structure of wheat gluten. The measured thermomechanical properties of the dough samples showed that when the HBF proportion increased, the mixed dough samples showed a significant increasing trend (P<0.05) in water absorption rate, formation time, and protein-weakening degree (C2), but an overall decreasing trend in gelatinization degree, stability, and starch retrogradation value. This indicates that the protein-weakening and gelatinization degrees of starch in mixed dough were significantly affected by HBF addition. Scanning electron microscopy and confocal laser scanning microscopy images revealed that adding a higher proportion of HBF hindered the gluten-starch interaction, thus disrupting the network structure of gluten. Raman and FT-IR spectra indicated that the protein spatial structure was altered and that the disulfide bonds were transformed from a relatively stable g-g-g configuration into an unstable t-g-t configuration. The disulfide bond content was found to be the highest (14.41 μmol/g) in the control group and 21.44% less than that of the control group when 50% HBF was added. In summary, the stability and spatial structure of wheat gluten were disrupted by the addition of HBF in any proportion. This study provides a theoretical foundation and practical reference for the development of cakes with HBF.