Research of Brewing Technology for Reducing the Content of Trans-2-Nonenal and Aging Precursor

Abstract:

The key factors influencing malt lipoxygenase（LOX） during saccharification period were studied，such as protein rest temperature，pH value，grinding degree，LOX activity of malt for reducing the content of trans-2-nonenal and aging precursor nonenal potential of wort and beer. The optimum process parameters were confirmed：protein rest temperature was 55~60 ℃，mash pH was 5.5，EBC grinder distance was 0.5 mm，LOX activity was as low as possible. Experimental results of large-scale production showed that when protein rest temperature was 55 ℃，and malt with lower LOX activity was used，the content of trans-2-nonenal and nonenal potential declined 6.7%~25.0% and 9.2%~20.3% respectively. Beer freshness score increased 4.2%~16.1%.