茶多酚对面包纹理结构的影响

Effect of Tea Polyphenols on the Texture of Bread

为明确茶多酚对面包纹理结构的影响,应用感官评分法对不同茶多酚添加量面包的纹理结构进行评判,运用图像分析技术检测不同茶多酚添加量对面包芯气孔特性的影响,采用扫描电镜观察面包微观结构的变化,并利用红外光谱研究其对面包蛋白质二级结构的影响。结果显示,随着茶多酚添加量的增加,面包纹理结构感官评分呈先上升后下降趋势;面包芯气孔的个数,、表面分率、稠密度呈先增加后降低趋势,而气孔平均半径呈先缩小后增大趋势;面筋网络结构的有序性和紧密度呈先增加后降低趋势;面包蛋白质二级结构中β-折叠和α-螺旋的含量呈先增大后减少趋势,而无规则卷曲和β-转角的含量呈先减少后增大趋势。当茶多酚添加量为0.4%时,面包纹理结构感官评分最高;面包芯气孔的个数、表面分率、稠密度最大,气孔平均半径最小;面筋网络结构最为紧密有序;β-折叠和α-螺旋含量最高,无规则卷曲和β-转角含量最低。由此可见,适量添加茶多酚可改变面包蛋白质二级结构,促进面筋网络结构形成,使面包内部纹理结构得到改善。

This study aimed to investigate the effect of tea polyphenols on the texture of bread. A sensory scoring method was used to evaluate the texture of bread with different additions of tea polyphenols. Image analysis technology was used to determine the effect of different amounts of tea polyphenols on the porosity of the bread core. A scanning electron microscope was used to observe the change in the bread microstructure. Fourier transform infrared spectroscopy was used to examine the secondary structure of bread proteins. The results showed that the sensory score of bread texture was increased first and then decreased with the increase in tea polyphenols. The bread core number,surface fraction,and density were initially increased and then decreased;however,the average radius of pores showed the opposite trend.The order and tightness of the gluten network structure were increased to a maximum followed by a decrease. The β-sheet and α-helix contents of the secondary structure of bread proteins showed an initially increasing trend followed by a decreasing trend;however,the random coil and β-turn contents showed the opposite trend.When the content of tea polyphenols was 0.4%,the sensory score of bread texture was the highest. The bread core number,surface fraction,and density were the largest,and the average radius was the smallest. The gluten network structure was the most closely ordered. The β-sheet andα-helix contents of the secondary structure of bread proteins were the highest,and the random coil and β-turn contents were the lowest. Therefore,the right amount of tea polyphenols could change the secondary structure of bread proteins,promote the formation of the gluten network structure,and improve the internal texture structure of bread.