Influence of malt browning degree on lipoxygenase activity

The development of off-flavour in pale beer is generally attributed to the oxidation of the intermediate products of lipid degradation catalysed by lipoxygenase during mashing. This paper deals with the effect of speciality malts, having different browning levels, on malt lipoxygenase. The results obtained showed that lipoxygenase activity, which was found to be present only in the pale malt, was affected by mashing temperatures above 63 °C and by the presence of Maillard reaction products in the speciality malts. In particular, the addition to pale malt of speciality malts, having high inhibitory capacity towards lipoxygenase but low colouring potential, was effective in reducing the off-flavour development in pale beer.