Influence of saliva on the sensory properties of US commercial smoke affected wines: Preliminary findings.

Previous research has suggested that the impact of smoke affected wines require human evaluation due to in-mouth changes in perception, perhaps associated with saliva. Smoke affected wines (n = 36) from three major wine growing regions in the US were sourced from commercial wineries. A subset of these wines (n = 7) were evaluated by a consumer panel (n = 57) and electronic tongue (e-tongue) to determine the influence of saliva in the sensory profile. Consumers assessed the wines for aroma and other sensory attributes, before and after individual saliva addition. Pooled saliva from consumers was used to treat all wines obtained (n = 36) and then analyzed using the e-tongue. Results showed that saliva did not significantly alter the overall aroma, other than fruity or woody aroma liking by consumers (p > .05). However, the presence of saliva significantly lowered overall liking in both red and white wines that were affected by smoke (p ≤ .05). Consumers rated the subset of smoke affected wines below the "might purchase" category, indicating these wines were not considered acceptable by consumers. When individual pairs of smoke affected wines (before and after saliva additions) were assessed using the e-tongue, the device was able to differentiate the pairs, validating potential usefulness to discern wine changes, though the discrimination indices were moderate to low (68.8% to 11.9%). Based on these data, in human ratings of the aroma and appearance of smoked affected wines, saliva decreased overall liking, and this was somewhat distinguishable by e-tongue analysis.

Sensory properties of 6- and 18-month-stored wines made with pectinase-producing non-Saccharomyces yeasts.

Recently, the use and commercial availability of non-Saccharomyces yeasts (NSY) in winemaking to reduce alcohol content have increased. However, research exploring the influence on sensory quality of the wine, particularly during storage, is limited. Therefore, the objective of this study was to characterize the sensory profiles of Merlot and Chardonnay wines made with pectinase-producing NSY, with added substrate, that is, pectin. Apple pectin (0 or 0.5 g/L) was added to Merlot and Chardonnay grape musts after inoculation with (a) only Saccharomyces cerevisiae or (b) a three species mixture of NSY; after 3 days, S. cerevisiae was added. Addition of NSY with added pectin resulted in higher concentrations of d-galacturonic acid and glycerol concentration in the wines after 6 months of aging. However, mouthfeel (viscosity or weight) of wines with or without added pectin as determined by a sensory evaluation panel was not altered by the presence of these yeasts. Significant interactions among the yeast utilized, pectin addition, and 6-month aging affected some flavors (solvent) of Merlot, while addition of NSY increased other attributes (cherry) during aging. No sensory differences were perceived among Chardonnay samples due to NSY; however, aging from 6 to 18 months increased the intensity of 40 sensory attributes. Though mouthfeel was not specifically affected, the utilization of NSY may be a useful tool to alter wine quality in Merlot by increasing specific aromas during storage. PRACTICAL APPLICATION: We found that must fermented with pectinase-producing non-Saccharomyces yeasts (NSY) modified the chemical composition of the final young wine. After one additional year of aging, an increase in cherry flavor was observed in Merlot wines made with NSY, which may increase perceived quality. Thus, the use of these pectinase-producing NSY may be a useful tool for winemakers.

Improving the chemical and sensory characteristics of red and white wines with pectinase-producing non-Saccharomyces yeasts.

This study examined the influence of pectinase-producing non-Saccharomyces yeasts on the chemical and sensory attributes of red and white wines with added pectin. Merlot and Chardonnay wines were produced with or without a mixture of pectinase-producing non-Saccharomyces yeasts (Cryptococcus adeliensis, Issatchenkia orientalis, and Pichia kluyveri) added to the must prior to alcoholic fermentation conducted by a commercial strain of Saccharomyces cerevisiae. To ensure sufficient substrate was present, varying concentrations of apple pectin (up to 1.25 g/L for red wines and 1.00 g/L for white wine) were added at the start of fermentation. After bottling, trained panelists (n = 10) analyzed these wines for aroma, flavor, taste, and mouthfeel attributes. For both wines, significant interactions were noted between the presence of non-Saccharomyces yeasts and pectin addition which affected pH, titratable acidity, and concentrations of D-galacturonic acid. While no significant sensory differences were observed among the red wines, limited changes were noted for white wines. However, a strong positive correlation was found between the D-galacturonic acid and buttery aroma for Chardonnay and with flavor for Merlot. Increasing D-galacturonic acid concentrations, through utilization of non-Saccharomyces yeasts, may improve the wine quality as a buttery aroma is often associated with high-quality Chardonnay. For both red and white wines, the utilization of these particular non-Saccharomyces yeasts significantly influenced chemical properties but yielded minor sensory changes without any faults. PRACTICAL APPLICATION: With the recent trend to reduce alcohol content in commercial wines, the interest in non-Saccharomyces yeasts has grown. This study showed that the addition of non-Saccharomyces yeasts, perhaps due to their pectinase activity, influenced the chemical characteristics of red and white wines with limited sensory differences, making these yeasts a useful tool for winemakers to modify wine properties.

Detection of Spicy Compounds Using the Electronic Tongue.

The consumption of spicy food products has increased, resulting in an increased demand for these products. The sensory evaluation of foods containing spicy compounds provides challenges due to their trigeminal innervation and associated sensory fatigue. Thus, for the routine evaluation of spices, a need exists for rapid and objective methods of analysis; the electronic tongue (e-tongue) provides a potential solution. The objective of this study was to evaluate the ability of the e-tongue to distinguish among spicy compounds at varying concentrations. Due to the diversity of spicy compounds, seven spicy compounds were selected: capsaicin, thymol, piperine, zingerone, p-cymene, menthol, and eugenol. For each of these compounds, a low concentration (1.427 × 10-5 to 0.85 mg/L), medium concentration (2.854 × 10-5 to 1.49 mg/L), and high concentration (0.0133 to 30.5 mg/L) were analyzed by the e-tongue. For each compound, the e-tongue discriminated among the concentrations with discrimination indices between 72% to 84%. Based on the responses of the e-tongue sensors, the samples formed three clusters. Cluster 1 contained menthol, eugenol, and p-cymene, cluster 2 contained capsaicin and thymol, and cluster 3 contained piperine and zingerone. Same-different sensory testing was completed on a representative sample from each cluster. Untrained consumers (n = 80) distinguished among the three clusters, verifying the clusters identified by the e-tongue. These results demonstrated that the e-tongue could be applicable in product development and the routine evaluation of spicy products. PRACTICAL APPLICATION: As the e-tongue differentiated among spicy compounds in an effective manner, it could be used instead of or alongside sensory evaluation when evaluating spicy compounds to reduce sensory fatigue associated with routine testing. Utilizing the e-tongue for spicy products will be an important area of research as the market for such products continues to grow.