HPLC determination of amino acids in musts and port wine using OPA/FMOC derivatives

Musts and port wines pose specific problems for amino acid analysis because of high sugar content. An HPLC technique was applied to the simultaneous quantification of primary and secondary amino acids in these matrices as their OPA-FMOC derivatives. This method enabled the fully automated analysis of 21 amino acids in 20 minutes. The average detection limit was 1.3 mmole/L, precision was 5%-12% for wine samples and accuracy by the standard addition method was 108.3 % (recovery value). Ten port wine and 43 must samples were analyzed for free amino acid contents. Proline represented 73% of the total for wine samples.