THE PRODUCTION OF LINOLEIC AND LINOLENIC ACID HYDROPEROXIDES DURING MASHING

To clarify the lipid oxidation mechanism during wort production, the production of hydroperoxides during mashing was studied using a chemiluminescence-HPLC method. Free linoleic and linolenic acids increased during mashing and their rates of increase were significantly accelerated at 65-degrees-C, indicating that lipase acts during mashing. Linoleic and linolenic acid hydroperoxides increased just after mashing-in, reached a maximum level after 10 min at 65-degrees-C, and then decreased. When malt with higher lipoxygenase activity was used or the mashing was started at a lower temperature, the production of both hydroperoxides significantly increased. When an inhibitor of lipoxygenase was added to the mash just before mashing, the production of both hydroperoxides drastically decreased. Therefore, it is suggested that lipoxygenase and lipase in malt plays an important role in the production of linoleic and linolenic acid hydroperoxides during mashing.