RT Journal Article
SR Electronic
T1 Impact of Frozen Storage on the Free Volatile Compound Profile of Grape Berries
JF American Journal of Enology and Viticulture
JO Am. J. Enol. Vitic.
FD American Society for Enology and Viticulture
SP ajev.2015.15087
DO 10.5344/ajev.2015.15087
A1 Étienne Ouellet
A1 Karine Pedneault
YR 2016
UL http://www.ajevonline.org/content/early/2015/12/23/ajev.2015.15087.abstract
AB Fruits stored at temperatures above 4°C are subject to rapid deterioration due to microorganisms, enzymes or oxidation reactions. Although freezing is not part of usual wine making process, freezing grape berry samples during veraison and harvest in order to postpone time-consuming analyses is common practice. In this study, the free volatile composition, including C6 compounds, monoterpenes, C13-norisoprenoids and benzene derivatives of fresh juice from two grape varieties (Thompson and Flame) was compared with those of frozen juice and juice extracted from previously frozen grapes (Juice-FRG) using GC-MS-SPME. Results showed that freezing the juice or extracting juice from previously frozen grapes, had a significant impact on the free volatile compound profile when compared to fresh samples, and that these differences were cultivar-dependent. Freezing of fruit juice or the whole berries affected most C6 compounds, monoterpenes, and C13-norisoprenoids to different extents, but it had little impact on benzene derivatives. Results suggest that care should be taken when carrying free volatile compound analyses from frozen grape berries or juice, and that other preservation method should be investigated to preserve grape berries aimed for volatile metabolites studies.