DETERMINATION OF AMINO-ACIDS IN APPLE EXTRACTS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A rapid and sensitive method for the simultaneous determination of primary amino acids in apple is described. After sample preparation, amino acids were derivatized with o-phthaldialdehyde/2-mercaptoethanol and separated on a reversed phase column with a gradient of phosphate buffer-tetrahydrofuran-methanol as the mobile phase. Detection was carried out with a fluorescence detector at excitation and emission wavelengths of 340 nm and 425 nm respectively. Recovery studies showed good results for all substances (91-109%) (with coefficients of variation ranging, from 0.1 to 9.0%). This method was applied to the monitoring of amino acids during the ripening of apples. © 1990 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.