Brown Marmorated Stink Bug Taint in Pinot noir: Detection and Consumer Rejection Thresholds of trans-2-Decenal

Abstract

Brown marmorated stink bug contamination in grape clusters results in the addition of an aroma compound, trans-2-decenal (T2D), to wine. Described as a green, musty aroma, it is considered detrimental to wine quality. The main focus of this study was to estimate the detection threshold (DT) and consumer rejection threshold (CRT) of T2D in Pinot noir, determine T2D’s impact on wine quality, and investigate potential consumer segmentation. The two thresholds were measured using an ascending forced choice method of limits applied to a series of triangle and paired comparison tests, and were estimated with a psychometric function whose significance was based on a binomial distribution as well as on d′ values based on Thurstonian models. The method of quantitation resulted in different T2D threshold levels. The DT of the panel was estimated to be 0.51 μg/L T2D from a psychometric fit and between 1.92 and 4.80 μg/L T2D based on Thurstonian scaled values. Similarly, for CRT, the psychometric function resulted in a threshold of 13.0 and 0.05 μg/L and d′ values between 4.80 and 12.00 μg/L. Wines containing T2D above the CRT were described as green, musty, and less fruity by a professional wine-tasting panel. When potential consumer segmentation was examined on the basis of the DT and CRT data, there was no direct link between sensitivity and preference. Based on these findings, the use of the CRT is recommended when establishing consumer tolerance levels of T2D in wine. Additionally, the use of d′, which provides a more sensitive method of threshold estimation, seems more appropriate for compounds, such as T2D, that negatively affect wine quality.