小麦不同程度萌发后其加工品质的变化

为了解小麦萌动和发芽程度对其加工品质的影响,以经80℃高温快速干燥和自然晾晒干燥处理的不同程度萌动(鼓泡、皮裂、露白)和发芽(芽长为小麦籽粒长度的一半、芽长与小麦籽粒长度相同)小麦为研究对象,测定其出粉率、沉降值及粉质特性指标。结果表明:随着小麦萌动和发芽程度的加深,小麦的出粉率,面团吸水率、形成时间、稳定时间及粉质指数均呈现下降趋势,面团弱化度则逐渐上升,而沉降值变化并无规律。高温快速干燥能抑制小麦吸水率的下降,延长面团的形成时间和稳定时间,由此可见,干燥可抑制萌动、发芽的小麦加工品质劣化,因此一旦发现小麦萌动应立即进行干燥。差异性分析可知,小麦在萌动和发芽过程中大部分加工品质指标均从皮裂期开始出现显著性差异,建议将处于皮裂期至芽长不超过籽粒长度作为判定生芽粒的标准。

Changes in processing quality of wheat after different degrees of germination

In order to understand the effect of germination degree on wheat processing quality,the indexes of flour yield,sedimentation value and farinographical properties of wheat germinated at different degrees( bubbling,seed coat cracking,revealing) and sprouted( the length of germ was half of the length of wheat grain,and the length of germ was as same as that of wheat grain) after high temperature rapid drying at 80 ℃ and natural air drying treatment were determined. The results showed that with the deepening of wheat germination degree,the flour yield,dough water absorption,formation time,stabilization time and Farinogram quality number all showed a downward trend,while the dough weakening degree gradually increased,and the sedimentation value changed irregularly. High temperature rapid drying could inhibit the decline of water absorption rate of wheat,prolong dough formation time and stability time. The results showed that drying could inhibit the deterioration of processing quality of germinating wheat,so once wheat germination was found,drying should be carried out immediately. Difference analysis showed that most of the processing quality indexes of wheat during germination had significant differences from the beginning of the seed coat cracking. It was suggested that the judgement criterion of germinated grain was that the wheat grain was in seed coat cracking stage to sprouting stage,in which the germ length did not exceed the grain length.