End-use quality of wheat affected by late maturity α-amylase

Abstract

Late maturity α-amylase (LMA) is associated with elevated α-amylase within the aleurone of wheat grains. The increased α-amylase contributes to a reduced falling number (FN). A reduction in FN also results from preharvest sprouting and frost during grain fill which are associated with poor baking quality. Low FN can also lead to downgrading of wheat at grain receival sites, reducing returns for wheat growers. A population created to investigate LMA expression was used to assess the impact of LMA on dough rheology, pan bread and yellow alkaline noodles. Elevated levels of α-amylase due to LMA were found to have a negative impact on dough development time, stability and mixing tolerance index. Elevated α-amylase also led to darker crust colour and increased loaf volume, however, the improvement in loaf volume was less than that produced by bread improver. The increased α-amylase content associated with LMA also reduced the brightness of cooked and uncooked yellow alkaline noodles and the strength of overcooked noodles. The detrimental effect of LMA on dough rheology and yellow alkaline noodles means that flours produced from LMA-affected grain have reduced utility in some important wheat markets.