Brewing performance of malted lipoxygenase-1 null barley and effect on the flavor stability of beer

We examined the malting and brewing performances of a lipoxygenase-1 (LOX-1) null line of barley (Hordeum vulgare L.). The LOX-normal malt and the LOX-null malt were prepared from F-4 populations derived from a single cross. We could not observe any major differences in the general malt characteristics between the two malts. A brewing trial was performed using these malts. The analysis of the wort and beer revealed that the absence of LOX-1 had little effect on the general characteristics of the wort and beer. In contrast, beer made from the LOX-null malt showed reduced levels of beer-deteriorating substances, trans-2-nonenal (T2N), and trihydroxyoctadecenoic acid (THOD). In the sensory evaluation, well-trained panel members recognized the significant superiority of the aged LOX-null beer in terms of staleness. These results show that the LOX-1 null barley line can be effectively used to improve the flavor stability of beer without changing the other important beer qualities.