title: Grape cluster microclimate influences the aroma composition of Sauvignon blanc wine.
abstract: New Zealand Sauvignon blanc (SB) wines are characterised by a distinctive combination of tropical-fruity and green-herbaceous aromatic compounds. The influence of sunlight exposure of grape clusters on juice and wine composition was investigated, with the aim of manipulating aromatic compounds in SB wine. In the absence of basal leaf removal SB clusters naturally exposed to sunlight were riper than shaded clusters, evidenced by higher total soluble solids (TSS) and proline, and lower malic acid, 3-isobutyl-2-methoxypyrazine (IBMP) and arginine. Volatile thiols in wines did not differ between shaded and exposed clusters. At equivalent TSS, cluster exposure had little or no effect on malic acid concentration. Conversely, wine from shaded clusters had almost double the IBMP concentration of wine from exposed clusters at equivalent TSS. The effects on SB juice and wine composition of natural variations in cluster microclimate are not comparable with the effects of cluster exposure created through leaf removal.
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, 85 Budge Street, Blenheim 7240, Marlborough, New Zealand. Electronic address: Damian.Martin@plantandfood.co.nz.
authors.forename: Damian
authors.initials: D
authors.lastname: Martin
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, 85 Budge Street, Blenheim 7240, Marlborough, New Zealand. Electronic address: Claire.grose@plantandfood.co.nz.
authors.forename: Claire
authors.initials: C
authors.lastname: Grose
authors.affiliation: Wine Science Programme, School of Chemical Sciences, University of Auckland, 23 Symonds Street, Auckland 1142, New Zealand. Electronic address: b.fedrizzi@auckland.ac.nz.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fedrizzi
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, 85 Budge Street, Blenheim 7240, Marlborough, New Zealand. Electronic address: Lily.Stuart@plantandfood.co.nz.
authors.forename: Lily
authors.initials: L
authors.lastname: Stuart
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, 85 Budge Street, Blenheim 7240, Marlborough, New Zealand. Electronic address: Abby.Albright@plantandfood.co.nz.
authors.forename: Abby
authors.initials: A
authors.lastname: Albright
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, Food Industry Science Centre, Private Bag 11600, Palmerston North 4442, New Zealand. Electronic address: Andrew.McLachlan@plantandfood.co.nz.
authors.forename: Andrew
authors.initials: A
authors.lastname: McLachlan
mesh_terms: D000383:Agriculture / Q000379:methods; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development*; D008293:Malates / Q000032:analysis; D008834:Microclimate; D009520:New Zealand; D018515:Plant Leaves; D011392:Proline / Q000032:analysis; D011719:Pyrazines / Q000032:analysis; D012903:Smell; D013438:Sulfhydryl Compounds / Q000032:analysis; D013472:Sunlight; D027843:Vitis; D014920:Wine / Q000032:analysis*
chemical_list: D008293:Malates; D011719:Pyrazines; D013438:Sulfhydryl Compounds; C030298:malic acid; D011392:Proline; C034376:2-isobutyl-3-methoxypyrazine
keywords: Cluster microclimate; Methoxypyrazines; Sauvignon blanc; Sunlight exposure; Thiols