Abstract

Poster Presentations

Day 2, June 11（Tue.）　　Room P1 (Multipurpose Hall)・Room P2 (Conference Room 101+102)

Barley malt is the main ingredient of beer and it is an important ingredient in beer brewing. It is known that the amount and composition of proteins in malt play a role in the flavor and foam quality of beer. Therefore, to control various exopeptidase activities expressed in barley malt during the malting process is important to improve beer quality. The distribution of exopeptidase reaction is important for the evaluation of exopeptidase activity in original state of barley malt. In this study, I focused on leucine aminopeptidase (LAP), one of exopeptidase and investigate the localization of LAP reaction in barley malts in order to obtain information that contributes to the evaluation of exopeptidase activity in the original state of malt. Moreover, enzyme histochemistry based on mass spectrometry imaging (MSI) was used to visualize the localization of the LAP reaction. The results of MSI analysis showed that the LAP reaction was localized in the aleurone layer and in the embryo. The optimal enzymatic reaction conditions of LAP reaction were found to be buffer pH 7.0, reaction temperature 50°C, and reaction time 15 minutes were optimal conditions. In this study, a method to visualize the localization of LAP reaction was established.

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