بررسی فعالیت آنزیم های آلفاآمیلاز، لیپاز و لیپواکسیژناز در گندم و تغییر فعالیت آنها در قبل و بعد از دوره جوانه زنی

Enzymes of wheat flour have an important role in production of various cereal products, especially bread, and therefore accurate measurement of enzymatic activity along with improvement of this characteristic is the basis of most studies in baking industry. In the present work, physical properties of three wheat varieties (Mahdavi, Kavir and M7318 that are cultivated in Isfahan province) and chemical characteristics of their flours were investigated. In order to study the changes in enzymatic activities (α-amylase, lipase and lipoxygenase), the activities of these enzymes were measured before and after germination. The relationship between root length and α-amylase activity was studied as well as the relation between lipase and lipoxygenase activities. α-amylase activity of flours was also optimized according to falling number 250 s. The effect of this optimization on the bread texture in four different times after baking, on the flour color in three different times, and on the flour acidity in two different times were then evaluated. The results of chemical measurements showed that M7318 and other two varieties can be considered as weak flours and medium flours, respectively, in terms of their protein and gluten contents. However, all varieties had low levels of α-amylase activity, although, kavir flour had more activity than the others. The results of germination tests indicated an increase in the activity of α-amylase and lipase, but not lipoxygenase. Moreover, during germination times a significant negative correlation between root length and falling number was found. Also, a significant positive correlation between root length and α-amylase activity and between activities of lipase and lipoxygenase was observed.