Comparison of New and Existing Threshold Methods for Evaluating Sulfur Compounds in Different Base Wines

Abstract

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.

Exploring the response to a new range of ethanol reductions in Chardonnay and Syrah wines using a Consumer Rejection Threshold approach

“…For the ASTM E 1432 procedure, thresholds of 1.55 and 1.82 % v/v were established for Chardonnay and Syrah respectively (Figure 2). The fact that lower difference thresholds were obtained for the ASTM E 679 is in accordance with previous work aiming at comparing the two methods (Cliff et al, 2011). Even though in agreement with previous observations (Yu and Pickering, 2008), the reason why a higher panel threshold -albeit non-significant according to ASTM E 679 and Mann-Whitney test (P = 0.404) -was observed for the red wine remains unclear.…”

Taste Detection Thresholds of Resveratrol

“…In a past study on mouthfeel detection threshold for sucrose and high fructose corn syrup, the average of individual panelist thresholds and pooled taste detection thresholds were similar to each other (Kappes and others ). In comparison, the pooled threshold of sulfur compounds in wines was 2‐ to 3‐fold higher than the average individual panelists’ threshold (Cliff and others ).…”

Olfactory Impact of Terpene Alcohol on Terpenes Aroma Expression in Chrysanthemum Essential Oils

“…The olfactory threshold of linalool in water reported 0.001 mg/L [ 34 ]; the olfactory threshold of linalool in alkane solution is 3.85 mg/L. While the evaluation of olfactory threshold could be affected by lots of factors [ 34 ], the olfactory threshold determination in the literature mostly uses water as the solvent, ignores the function of non-volatile compounds on the thresholds of aromatic compounds [ 35 ]. The differences in olfactory threshold between the obtained results and literature data proofed the matrix affected the intensity of volatile aroma compounds.…”