Understanding the relationship between tropical fruit aroma, acceptance, and emotional response in chardonnay wines.

Tropical fruit aromas are prominent in many white wines. The purpose of this work was to determine if winemaking practices could impact the tropical fruit aromas in the Chardonnay wines and how those aroma differences influenced wine consumers acceptance and emotional responses. Four treatments were tested at varying fermentation temperature gradients and skin contact times: control fermentation at 13 °C with no skin contact (Control), fermentation at 13 °C with 18 h of skin contact (SC), fermentation temperature gradient by time (20 °C for 4 days then reduced to 13 °C) with no skin contact (FG), fermentation temperature gradient by time with 18 h of skin contact (SCFG). Acceptance, using a 7-point hedonic scale, showed there was not a significant difference between treatments. Emotional response, using a 5-point Rate-All-That-Apply (RATA) scale, showed significant differences for 'calm' and 'disgusted' emotions. Check-all-that-apply (CATA) for aroma descriptors showed that Control is described using aromas of passionfruit, lychee, and pome fruit; SC had aromas of grapefruit and floral; FG was described as having melon, lychee, and pineapple aromas; and SCFG was described with aromas of lemon/lime, mango, and guava. Positive emotions were associated with fruity aromas in the wines, although no difference in acceptance was found. Winemaking treatments impacted the aroma profile of chardonnay wine, with tropical aromas evoking positive emotions in consumers. The relationship between specific aromas and consumers emotion responses can be an important tool to understand the factors behind a wine's success or lack thereof. Moreover, it can help with the creation of new wine products.

Potential use of Starmerella bacillaris as fermentation starter for the production of low-alcohol beverages obtained from unripe grapes.

To obtain beverages with reduced alcohol content, the use of unripe grapes, with low sugar and high malic acid concentration, was recently explored. Due to the low sugar, ethanol and glycerol production is limited during fermentation affecting important sensory aspects such as the palate fullness of these beverages. The high acidity influences their organoleptic quality, as well. So far, only S. cerevisiae starter, used in conventional fermentations, have been tested in this condition, and no selection has been performed to identify alternative yeasts suitable for unripe grape fermentation. S. bacillaris is known for the low ethanol tolerance, high glycerol and moderate volatile acidity production. Therefore, this non- Saccharomyces yeast have been investigated to improve the quality of low-alcohol beverages. Seven S. bacillaris strains were tested in synthetic musts with different sugar and malic acid levels, mimicking natural ripe and unripe grape musts. In all the tested conditions, S. bacillaris produced higher glycerol than S. cerevisiae. In single-strain fermentation at low sugar and high malic acid no S. bacillaris strains was able to transform all the sugars, although the produced ethanol was lower than that at high sugar condition. Therefore, sequential fermentations with S. cerevisiae were evaluated at low sugar and high malic acid. In this condition all the sugars were consumed and a significant glycerol increase was found. These results were confirmed when sequential fermentations were run in natural unripe grape must. Moreover, an increase in malic acid degradation, with respect to EC1118 single-strain fermentation, was observed.