Content of phenols in wheat as affected by varietal and agricultural factors

This study evaluates the concentration of various forms of ferulic acid in wheat and in wheat varieties grown under comparable organic and conventional conditions over two years. The effect of fungicide application in 2009 was also studied. Soluble conjugated and bound forms of ferulic acid were quantified by HPLC-PAD after extraction, the bound form was present predominantly up to 85–90% of total content. In 2008 the bound form of ferulic acid was measured in the range of 248–550 μg/g, the conjugated form was between 11 and 40 μg/g in all the wheat cultivars as a function of (NPK) treatments. Total ferulic acid content measured in 2009 varied in the range of 275–435; 267–341; 296–378 μg/g, with fungicide and 189–394; 231–366; 182–324 μg/g without fungicide in varieties Békés, Csillag and Petur respectively. In 2008 a significantly higher amount of conjugated ferulic acid was measured in all three investigated cultivars as compared to the content found in 2009 for the same cultivars. As all the samples were treated with fungicide, the main factor was the year (climate conditions). The combination of NPK, fertilizers did not affect significantly the ferulic acid concentration, on the other hand the year (climate conditions) influenced significantly the soluble conjugated ferulic acid content in all fungicide treated varieties.