Expedient Soxhlet extraction of resorcinolic lipids from wheat grains

The main objective of this study was to select the most suitable organic solvent for the extraction of alkylresorcinol fractions from wheat grains. Lipids were isolated in the Soxhlet apparatus. The solvents examined were acetone, chloroform, cyclohexane, diethyl ether, ethyl acetate and hexane. Each solvent yielded extracts that differed from each other in terms of resorcinolic lipid contents and homologue compositions as well as for the presence of contaminating ballast substances. The highest amounts of total resorcinolic lipids were found in acetone and ethyl acetate extracts, whereas as many as of 13 resorcinolic homologues were determined in the cyclohexane extract. Because of low contents of ballast substances and a complete absence of compounds cross-reacting with the diazonic salt Fast Blue B, the latter was suitable for direct qualitative and quantitative determinations of alkylresorcinol. The extraction using the Soxhlet apparatus and cyclohexane was shown to be faster and more versatile than previously published procedures.