小麦特一粉和特二粉的面筋聚集特性分析

Aggregation characteristic analysis of gluten in first-grade and second-grade wheat flour

以小麦特一粉和特二粉为材料,设计四因素(水粉比、温度、转速、面粉质量)三水平正交试验及单因素试验,利用面筋聚集仪检测和记录样品的最大峰值时间(PMT)和最大扭矩(BEM)。正交试验极差结果显示,4个因素对PMT和BEM的影响顺序分别是水粉比>温度>转速>面粉质量、水粉比>面粉质量>转速>温度;Duncan’s多重比较结果显示,水粉比3个水平之间有显著差异(P<0. 05),其余3个因素3个水平之间未达到显著差异。单因素试验结果表明:转速在1 000~2 500 r/min时,特二粉的BEM与转速呈线性相关(R^2=0. 991 6);转速在1 800~2 000 r/min时,特一粉的PMT变化较小,而特二粉的PMT变化较大,可作为区分二者的一个指标;温度在20~45℃时,特一粉、特二粉的PMT和BEM随温度的增加均逐渐减小,且特一粉的PMT和BEM均低于特二粉的;Pearson相关系数分析表明,特一粉、特二粉的BEM和PMT与温度有极强的相关性。综上,面粉面筋聚集特性中的PMT和BEM可在一定程度上反映不同面粉的品质差异,可为微量快速分析面粉品质提供新的有效途径。

In this study,first-grade wheat flour( FF) and second-grade wheat flour( SF) were employed as materials. A set of variables such as the ratio of water to flour,temperature,rotating speed and flour weight were evaluated by single factor experiment and orthogonal design.Peak maximum time( PMT) and Brabender equivalents maximum torque( BEM) collected by Glutopeak were used as indicators. Extremum difference analysis results showed that influence of these four factors on the PMT followed the order of waterflour ratio > temperature > rotating speed > flour weight,while on the BEM,it followed the order of water-flour ratio > flour weight > rotating speed > temperature. LSD Duncan’s test showed that there were significant differences among the three levels of water-flour ratio( P<0. 05),and for the other three factors,the differences were insignificant. Single factor experiments showed that the BEM of SF was linearly correlated with rotating speed( R^2 = 0. 991 6) in the range of 1 000-2 500 r/min. Within a rotating speed range of 1 800-2 000 r/min,the PMT of SF changed more than the one of FF,indicating that PMT could be used to distinguish between FF and SF. The PMT and BEM of FF and SF gradually decreased with rising temperature from 20 ℃ to 45 ℃ and the formers’ values were lower than the latters’. Pearson correlation coefficient indicated a strong correlation between the BEM or PMT of FF and SF and temperature. To conclude,the PMT and BEM can reflect the quality difference of flours to some extent,thus providing a new effective approach for rapid micro-evaluation for flour quality.