Cultivar differences in lipoxygenase activity affect volatile compound formation in dough from wheat mill stream flour

Abstract

Flavor, an important aspect of wheat (Triticum aestivum) dough products, forms during preparation and is affected by the generation of volatile compounds. These compounds are produced mainly by the oxidation of unsaturated fatty acids by lipoxygenase (LOX). Here, we analyzed the volatile compounds emitted from dough made from wheat mill stream flour to clarify the cultivar differences in LOX distribution and its effect on the formation of volatile compounds. LOX activity increased with ash content, and the rate of increase was significantly higher for Norin 61 than for other wheat cultivars. The volatile compound profiles were analyzed by principal component analysis, with almost all volatile compounds correlated to ash content. The volatile compounds in some Norin 61 streams, however, were more characteristic of the outer layer of wheat kernels than those in the other cultivars. Since the ash content among cultivars was similar, the characteristic volatile compound profiles of Norin 61 were presumed to be caused by higher LOX activity in this cultivar. In conclusion, the characteristic volatile compound profiles in each cultivar are due to the differences of LOX activity.