Botrytized wines thiols

The amounts of thiols formed during alcoholic fermentation are strongly affected by the previous development of B. cinerea (Table 6.7). Since these compounds have extremely low sensory thresholds, and seem remarkably stable in wine, 3SH particularly plays a significant role in the fruity aroma of botrytized wines (Dubourdieu and Tominaga, 2009). 

The nature of the Botrytis aroma compounds has been subjected to extensive research. In addition to the older findings about the importance of hydroxy-, oxo-, and dicarboxylic acid esters, acetals, and some special y- and 8-lactones, the role of volatile thiols has recently been elucidated. Nonetheless, additional research is needed to identify odor active compounds that are specific for botrytized wines. 

Table 8B.5 Assay of volatile thiols (ng/L) in young botrytized wines from various appellations of the Bordeaux region (Sarrazin et al. 2007)...

Sarrazin, E., Shinkaruk, S., Tominaga, T., Bennetau, B., Frerot, E., and Dubourdieu, D. (2007b). Odorous impact of volatile thiols on the aroma of young botrytized sweet wines Identification and quantification of new sulfanyl alcohols. /. Agric. Food Chem. 55,1437-1444. 

The yeast strain used for fermentation had no impact on the enantiomer distribution of these volatile thiols. 3SHA is generally considered to be formed by esterification of 3SH by yeast during alcoholic fermentation. The esterase or lipase involved probably acetylates 3SH with a certain enantioselectivity. In contrast, the enantiomer distribution of 3SH in wine made from botrytized grapes (Botrytis cinerea) is 25 75 in favor of the S form, which has also been found in botrytized must (Thibon et al. 2007,2008a). 

Research by Tominaga et al. (2000) (Table 7.8) showed that the thiols identified in Sauvignon Blanc wines also contributed to the aroma of several Alsace grape varieties, as well as Colombard, Manseng, and botrytized Semilion. 

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