Behavior of Lipid Hydroperoxides During Mashing. Naoyuki Kobayashi, Hirotaka Kaneda, Yukinobu Kano, and Shouhei Koshino, Brewing Research Laboratories, Sapporo Breweries Ltd., 10 Okatohme, Yaizu-Shi, Shizuoka, 425 Japan. J. Am. Soc. Brew. Chem. 52:0141, 1994.

Lipid hydroperoxides such as trilinolein hydroperoxides in barley, malt, and mash were analyzed using a chemiluminescence high-performance liquid chromatography method. During mashing in a laboratory mash bath, the hydroperoxides increased for a short time just after mashing-in but soon gradually decreased. The increasing peaks of lipid hydroperoxide production occurred before those of the free fatty acid hydroperoxides. The malt with higher lipoxygenase activity produced more lipid hydroperoxides during mashing. This study confirms the contribution of malt enzymes such as lipoxygenase and lipase to lipid oxidation and clarifies the lipid oxidation mechanism during mashing.

Keywords: Chemiluminescence-HPLC, Hydroperoxides, Lipase, Lipid, Lipid oxidation mechanism, Lipoxygenase