Influence of oxygen availability during skin‐contact maceration on the formation of precursors of 3‐mercaptohexan‐1‐ol in Müller‐Thurgau and Sauvignon Blanc grapes. (19th August 2013)

• Record Type: Journal Article
• Authors: Larcher, R.; Nicolini, G.; Tonidandel, L.; Román Villegas, T; Malacarne, M.; Fedrizzi, B.
• Is Part Of: Australian journal of grape and wine research. Volume 19:Number 3(2013:Oct.)
• Page Start: 342
• Page End: 348
• Publication Date: 2013-08-19
• Subjects: Viticulture -- Australia -- Periodicals; Wine and wine making -- Australia -- Periodicals; Viticulture -- Periodicals; Wine and wine making -- Periodicals; 634.80994
• DOI: 10.1111/ajgw.12039
• Languages: English
• ISSNs: 1322-7130

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="ajgw12039-sec-0001" sec-type="section"> <title>Background and Aims</title> <p>Grape maceration plays an important role in the formation of precursors of 3‐mercaptohexan‐1‐ol (3MH), 3‐S‐glutathionyl mercaptohexan‐1‐ol (GSH‐3MH) and 3‐S‐cysteinyl mercaptohexan‐1‐ol (Cys‐3MH), but its contribution is still not well understood. The aim of this paper was to study the effect of oxygen deprivation on the concentration of these 3MH precursors during skin‐contact maceration in two grape cultivars.</p> </sec> <sec id="ajgw12039-sec-0002" sec-type="section"> <title>Methods and Results</title> <p>Müller‐Thurgau (<italic>n</italic> = 19) and Sauvignon Blanc (32) grapes from Trentino (Italy) were hand harvested and processed under the following conditions: reductive (air protected; 80 mg/kg sulfur dioxide, 80 mg/kg L‐ascorbic acid, and 200 mg/kg dimethyl dicarbonate) and oxidative (no addition of adjuvants and air contact). After maceration, GSH‐3MH and Cys‐3MH were analysed by liquid chromatography‐mass spectrometry and isotopic dilution.</p> </sec> <sec id="ajgw12039-sec-0003" sec-type="section"> <title>Conclusions</title> <p>Both GSH‐3MH and Cys‐3MH were identified for the first time in Müller‐Thurgau juices. Oxidative maceration increased the GSH‐3MH concentration in 16 out of 19 Müller‐Thurgau and in 23 out of 32 Sauvignon Blanc juices, while Cys‐3MH was higher in 13 and 20 juices, respectively, of the two cultivars. Parametrical and non‐parametrical statistical tests confirmed that oxidative maceration of Müller‐Thurgau increased GSH‐3MH concentration significantly (<italic>P</italic> < 0.01).</p> </sec> <sec id="ajgw12039-sec-0004" sec-type="section"> <title>Significance of the Study</title> <p>This work highlights the complexity of the mechanisms involved in the potential <italic>de novo</italic> formation of thiol precursors.</p> </sec> </abstract>