Quantitative determination of 2,5-dimethyl-4-hydroxy-3(2H)-furanone and its methyl ether using a stable isotope, dilution assay

A stable isotope dilution assay has been developed for the quantitative determination of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DHF) and its methyl ether in fresh and processed fruits. Application of the method to strawberries (fresh fruits, juice, jam, candies), pineapples (juice, jam) and blackberries has indicated that both compounds can be determined with a high degree of sensitivity and accuracy. Analysis of a strawberry suspension treated with β-glucosidase at pH 6.8 showed a 3.5-fold increase of the DHF level.