'Fatty acid hydroperoxide lyase' as a key enzyme for the production of trans-2-nonenal during mashing

摘要

Trans-2-nonenal, the major contributor of cardboard flavour during the storage of beer, is produced by the cascade reaction of barley lipoxygenase-1 and 9-fatty acid hydroperoxide lyase-like activity (9-HPL-like activity) during mashing (Kuroda et al. 2003). In this study, we found that partially purified 9-HPL-like activity had properties specific to an enzyme 'fatty acid hydroperoxide lyase (HPL)'. There was significant correlation between malt HPL activity and nonenal potential, an index for predicting the degree of staleness of beer, suggesting that malt HPL would be a useful marker to select malts for producing beer with stable flavour.