Rejection of labrusca-type aromas in wine differs by wine expertise and geographic region

Methyl anthranilate (MA) and 2-aminoacetophenone (2AAP) are commonly associated with the flavor of wines made from V. labruscana grapes. It is widely assumed that wine experts and consumers find these flavors to be objectionable, at least in wines vinified from V. vinifera grapes. Here, a two-alternative forced-choice task was used to compare preference for unoaked Chardonnay against the same Chardonnay spiked with MA or 2AAP in ascending concentration series. Participants were either wine experts from California, or non-expert wine consumers from California or Pennsylvania. Wines were evaluated in the mouth and participants were instructed to indicate which sample within a pair they preferred. Rejection threshold estimates were determined by regressing 2AFC responses against concentration. Consistent with the expectation that experts view V. labrusca associated odors as a fault, wines with high concentrations of methyl anthranilate were largely rejected by wine experts in California. However, non-expert consumers in California were more tolerant than the wine experts in California, and non-expert consumers in Pennsylvania showed little to no influence of added methyl anthranilate on their preferences. Contrary to expectations however, 2-aminoacetophenone failed to elicit rejection in California wine experts or consumers within the range tested. Our results suggest that while V. vinifera wines may occasionally contain amounts of methyl anthranilate and 2-aminoacetophenone that are detectable in chemical analysis, the presence of these odorants at levels naturally found in V. vinifera wines is insufficient to elicit rejection from wine experts or consumers, regardless of their regional wine culture.