Comparison of supercritical carbon dioxide and ethyl acetate extraction of alkylresorcinols from wheat and rye

In this study, the application of supercritical carbon dioxide extraction of alkylresorcinols (AR) was quantitatively and qualitatively compared to a commonly used ethyl acetate extraction procedure. No difference in total AR content, relative homolog composition or total extract yield was found between the two extraction methods. Ethyl acetate extraction of intact wheat and rye kernels yielded only 9-20% of the total extract weight obtained with milled samples, but the same amount of alkylresorcinols, showing the benefit of analyzing intact grains whenever it is possible. The major compounds in all extracts (R_f=0.8) were fatty acids in esterified form, most probably fatty acid alcohol esters. The two different extraction techniques produced comparable results under the conditions used, which suggests that issues other than performance need to be considered when choosing an appropriate technique.