RT Journal Article T1 Occurrence of melatonin and its precursors in wines marketed in Spain determined through a validated UHPLC-MS/MS method A1 García-Serrano, Pedro A1 González-Ramírez, Marina A1 Valero Blanco, Eva María A1 Troncoso, Ana M A1 García-Parrilla, M. Carmen K1 Wine K1 Melatonin K1 Serotonin K1 Matrix effect K1 UHPLC/MS-MS AB Melatonin (MEL) is a compound present in foods and fermented beverages such as wine and beer which has attracted the interest of many researchers due to its bioactive properties. MEL is synthetized by yeast during alcoholic fermentation. This article aims to develop and validate an analytical method by ultra-high-performance liquid chromatography coupled to mass spectrometry (UHPLC-MS/MS) to determine MEL and its related compounds (L-tryptophan, tryptamine, serotonin, tryptophol, N-acetylserotonin, 5-hydroxytryptophan, and indole-3-acetic acid) and secondly, to study its presence in wines in a total of 85 commercial Spanish wine samples (53 red and 32 white wines). The concentration of MEL in red wines is significantly higher (13.21–347.50 ng mL-1) than in white wines (1.35–230.57 ng mL-1). It is noteworthy that all wine samples are grouped according to the type of wine. This is the first time that a study of MEL precursors in a large sample of wines has been carried out contributing to expanding the knowledge of the chemical composition and bioactive potential of wines. PB Elsevier YR 2025 FD 2025-07-24 LK https://hdl.handle.net/10433/25355 UL https://hdl.handle.net/10433/25355 LA en NO Journal of Food Composition and Analysis 147 (2025) 108064 NO Universidad Pablo de Olavide. Departamento de Biología Molecular e Ingeniería Bioquímica DS RIO RD May 9, 2026