This research determined the aroma threshold of three sulfur compounds by novel (R‐index) and standard ASTM International methodologies. Thresholds for dimethyl disulfide (DMDS), dimethyl sulfide (DMS) and ethyl thioacetate (EtSOAc) were determined in a “model” wine, a “neutral” white wine (Sauvignon blanc) and a “fruity” white wine (Gewurztraminer) by 24 untrained panelists. Panelists were presented with two replicates for the ASTM methods and four replicates for the R‐index method. The group threshold, for each compound, was calculated by ASTM E679, ASTM E1432 and R‐index methods. The range of aroma thresholds obtained for DMDS, DMS and EtSOAc in different bases were 7.5–151.0, 9.4–651.0 and 8.5–95.9 µg/L, respectively. The thresholds were influenced significantly by wine type and the method of evaluation. In general, the thresholds obtained using the R‐index method were higher yet significantly corrrelated with the thresholds obtained by ASTM methods (r = 0.9899, R‐index and ASTM E1432; r = 0.9848, R‐index and ASTM E679). The thresholds in the neutral wines were observed to be lower as compared with those in the aromatic wines. This research was successful in determining sulfur thresholds for possible use in quality control and research by the wine industry and in understanding the relationship among thresholds reported by different methods.
PRACTICAL APPLICATIONS
This research evaluated the aroma thresholds for sulfur compounds in wines by different methods. The new method, R‐index, was significantly correlated with the standard methodologies (ASTM International) and could be used to save time and money.