Electronic Nose Analysis of Cabernet Sauvignon (Vitis viniferaL.) Grape and Wine Volatile Differences during Cold Soak and Postfermentation

Abstract

Cold soak is a prefermentation maceration process at cold temperatures, traditionally used to enhance red wine color. This study monitored changes in Vitis vinifera L. cv. Cabernet Sauvignon volatiles using a commercial conducting polymer electronic nose (ENose) during a five-day cold soak and postfermentation. Principal component analysis (PCA) of juice volatiles detected by the ENose during cold soak showed PC1 accounted for 95.7% of the variation. Various volatile associations were made with specific ENose sensors. In comparison, PCA of must chemistries had 52.4% of the variation accounted for by PC1. The PCA of wine volatiles detected by GC-MS showed PC1 accounted for 97.1% of the variation between control and cold soak treatment, where control wine volatiles were associated with several ethyl esters, while cold soak wine volatiles were associated with diethyl succinate, isovaleric acid, benzyl alcohol, 3-methyl butanol, cis-3-hexenol, γ-nonalactone, benzaldehyde, 2-methyl propanol, phenethyl acetate, 1-octanol, β-damascenone, terpinene-4-ol, γ-butyrolactone, ethyl acetate, hexanoic acid, citronellol, phenethyl alcohol, and n-butanol. Comparatively, PC1 accounted for 100% of the total variance when using the ENose to measure volatile composition. Sensory evaluation did not demonstrate significant differences in aroma between control and cold soak wines. This study demonstrates differences in volatile chemistry between control and cold soak wines, as well as the ability to use a conducting polymer ENose as a simple tool for analysis of volatiles.

Sensory and chemical effects of two alternatives of prefermentative cold soak in Malbec wines during winemaking and bottle ageing

“…Table revealed that the colour enhancement in CS‐DI wines was significant and perceptible when compared with CS‐T, but not with C. In addition, both the visible spectrum and colour difference favoured C wines when compared with CS‐T. These results suggest an overall negative effect of CS‐T in Malbec wine colour, a result also reported in Cabernet Sauvignon (Gardner et al ., ), Sangiovese (Parenti et al ., ) and Mencía wines (Pérez‐Lamela et al ., ). After MLF, the visible spectrum of CS‐T decreased further, and, additionally, differences between CS‐DI and C wines became apparent based on ΔE* values > 5 CIELab units.…”

Effect of winemaking techniques on polysaccharide composition of Cabernet Sauvignon, Syrah and Monastrell red wines

“…Gardner et al (2011) detected a 1.5% increase in the ethanol content when cold prefermentative maceration was applied. Gardner et al (2011) detected a 1.5% increase in the ethanol content when cold prefermentative maceration was applied.…”

“…Cabernet Sauvignon wines showed a higher alcohol content when the five treatments were applied. Gardner et al (2011) detected a 1.5% increase in the ethanol content when cold prefermentative maceration was applied. In contrast, Doco et al (2007) and observed no differences in the ethanol produced when enzymatic treatments were applied compared with that of the control.…”

Evaluation of Volatile Metabolites Emitted In-Vivo from Cold-Hardy Grapes during Ripening Using SPME and GC-MS: A Proof-of-Concept

“…Levels of linalool, hexanal, ( E )-2-hexenal, hexanol, and ( Z )-3-hexene-1-ol, nerol in berry skins and pulp were influenced by storage temperatures post-harvest [9]. Viticultural practices such as the timing of early defoliation have been investigated to determine the effect on Tempranillo wine aroma [10], and enological practices such as effects of pre-fermentation cold soaking on Cabernet Sauvignon grape and wine volatiles [11]. The bulk of the research into the aroma of grapes and wine has been done for vinifera because vinifera has existed longer than hybrid grapes.…”