title: The effect of linoleic acid on the Sauvignon blanc fermentation by different wine yeast strains.
abstract: The level of linoleic acid in the Sauvignon blanc (SB) grape juice affects the development of different aroma compounds during fermentation by Saccharomyces cerevisiae EC1118, including key varietal thiols such as 3-mercaptohexanol (3MH) and 3-mercaptohexyl acetate (3MHA). However, it is still unknown if linoleic acid would affect in a similar way other commonly used S. cerevisiae wine strains. Here we investigated the effect of grape juice linoleic acid on the development of aroma compounds and other metabolites of SB wines using different wine yeast strains: EC1118, AWRI796 and VIN13. Linoleic acid clearly affected the levels of acetylated aroma compounds, several amino acids, and antioxidant molecules, independent of yeast strain, but the production of 3MH was affected by linoleic acid in a strain-specific manner. Moreover, the supplementation of deuterium-labelled 3MH also affected the production of varietal thiols in a strain-specific way. Linoleic acid reduced the acetylation process probably by inhibiting an acetyltransferase, an effect that was independent of the yeast strain. However, regulation of the 3MH biosynthesis is strain-specific, which suggests a mindful consideration not only towards the wine yeast but also to the linoleic acid concentration in the grape juice in order to obtain the desired wine aroma characteristics.
authors.affiliation: School of Biological Sciences, the University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.
authors.forename: Francesca
authors.initials: F
authors.lastname: Casu
authors.affiliation: The New Zealand Institute for Plant and Food Research Limited, 120 Mt Albert Rd, Sandringham, Auckland 1025, New Zealand.
authors.forename: Farhana R
authors.initials: FR
authors.lastname: Pinu
authors.affiliation: School of Chemical Sciences, the University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fedrizzi
authors.affiliation: School of Biological Sciences, the University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand The New Zealand Institute for Plant and Food Research Limited, 120 Mt Albert Rd, Sandringham, Auckland 1025, New Zealand.
authors.forename: David R
authors.initials: DR
authors.lastname: Greenwood
authors.affiliation: School of Biological Sciences, the University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand s.villas-boas@auckland.ac.nz.
authors.forename: Silas G
authors.initials: SG
authors.lastname: Villas-Boas
mesh_terms: D005285:Fermentation; D005421:Flavoring Agents / Q000378:metabolism*; D019787:Linoleic Acid / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism*; D014920:Wine / Q000032:analysis / Q000382:microbiology*
chemical_list: D005421:Flavoring Agents; D019787:Linoleic Acid
keywords: Metabolite profiling; esters; fatty acids; gas chromatography and mass spectrometry; polyphenolic compounds; varietal thiols; Δ9Z,12Z-Linoleic acid