High Performance Liquid Chromatography of 2,5‐Dimethyl‐4‐Hydroxy‐3 (2H)‐Furanone in Pineapple and Grapefruit Juices

A reversed‐phase HPLC method was developed for rapid analysis of 2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanone (DMHF), the compound responsible for the “burnt‐pineapple” flavor in pineapple juices. A Zorbax ODS column was used with a mobile phase of 0.05M sodium acetate (pH 4.0)/methanol (70:30); detection was by UV at 290 nm. Sample clean up was accomplished by solid‐phase extraction with C‐18 Sep‐Pak cartridges. DMHF contents ranged from 1.6 to 27.3 ppm from 10 fresh pineapple juices. Using this system, the production of DMHF was monitored in canned grapefruit juices during storage at varying temperatures.