Changes of free ferulic and coumaric acid contents during malting of barley grain

Abstract

The aim of the presented work was to evaluate changes in free ferulic and coumaric acid concentrations during malting. In general, malting is performed at 14°C and in steeping water of pH 7.4. The influence of an elevated temperature of the malting process (22°C, Activated Germination Malting technique) as well as a decreased pH value of steeping water (pH 5.2) on free ferulic acid and coumaric acid contents in kilned malts was estimated. The application of Activated Germination Malting caused a limited increase in the concentrations of ferulic acid and coumaric acid in malt Rudzik, whereas a higher temperature during malting of Krona barley resulted in approx. 2-fold higher concentration of both free phenolic acids in kilned malt. The use of steeping water of pH 5.2 instead of 7.4 resulted in a significant increase in the contents of free ferulic and coumaric acids in malt of both tested varieties, which could lead to an increase in the contents of these phenolic acids in beer.