title: Volatile compounds formation in alcoholic fermentation from grapes collected at 2 maturation stages: influence of nitrogen compounds and grape variety.
abstract: The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 wk before harvest and at harvest. Then, the musts were inoculated with the same Saccharomyces cerevisiae yeast strain and were fermented in the same winemaking conditions. Amino acids that showed the highest and the lowest concentration in the must were the same, regardless of the grape variety and maturation stage. Moreover, the consumption of amino acids during the fermentation increased with their concentration in the must. The formation of volatile compounds was not nitrogen composition dependent. However, the concentration of amino acids in the must from grapes collected 1 wk before harvest can be used as a parameter to estimate the concentration of esters in wines from grapes collected at harvest and therefore to have more information to know the grape oenological capacity. Application of principal components analysis (PCA) confirmed the possibility to estimate the concentration of esters in the wines with the concentration of nitrogen compounds in the must.
authors.affiliation: Cátedra de Química Agrícola, ETSI Agrónomos, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Martínez-Gil
authors.forename: Teresa
authors.initials: T
authors.lastname: Garde-Cerdán
authors.forename: Cándida
authors.initials: C
authors.lastname: Lorenzo
authors.forename: José Félix
authors.initials: JF
authors.lastname: Lara
authors.forename: Francisco
authors.initials: F
authors.lastname: Pardo
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Salinas
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development / Q000382:microbiology; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017672:Nitrogen Compounds / Q000378:metabolism*; D009812:Odorants; D025341:Principal Component Analysis; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013030:Spain; D013045:Species Specificity; D027843:Vitis / Q000737:chemistry* / Q000382:microbiology; D055549:Volatile Organic Compounds / Q000378:metabolism*; D014920:Wine / Q000032:analysis* / Q000382:microbiology
chemical_list: D000596:Amino Acids; D017672:Nitrogen Compounds; D000644:Quaternary Ammonium Compounds; D055549:Volatile Organic Compounds; D000431:Ethanol