The fermentation of fruit produces significant changes in their nutritional composition. An orange beverage has been obtained from the controlled alcoholic fermentation and thermal pasteurization of orange juice. A study was performed to determine the influence of both processes on its amino acid profile. UHPLC-QqQ-MS/MS was used for the first time for analysis of orange juice samples. Out of 29 ami-no acids and derivatives identified, eight (ethanolamine, orni-thine, phosphoethanolamine, α-amino-n-butyric acid, hy-droxyproline, methylhistidine, citrulline, and cystathionine) have not previously been detected in orange juice. The amino acid profile of the orange juice was not modified by its processing , but total amino acid content of the juice (8194 mg/L) was significantly increased at 9 days of fermentation (13, 324 mg/L). Although the pasteurization process produced partial amino acid degradation, the total amino acid content was higher in the final product (9265 mg/L) than in the original juice, enhancing its nutritional value. Abbreviations His histidine Met-His 1-methyl-histidine p-Hyp 4-hydroxyproline Asn asparagine PEA phosphoethanolamine Arg arginine Gln glutamine Ser serine EA ethanolamine Gly glycine Asp aspartic acid Cit citrulline Glu glutamic acid Thr threonine Ala alanine GABA γ-amino n-butyric acid Pro proline GSH glutathione Orn ornithine AABA α-amino-n-butyric acid