Contribution of Starmerella bacillaris and Oak Chips to Trebbiano d'Abruzzo Wine Volatile and Sensory Diversity

Sniffing the wine differences: The role of Starmerella bacillaris biofilm-detached cells

This study investigated the impact of 10 strains of Starmerella bacillaris, co-inoculated as planktonic or biofilm-detached cells with Saccharomyces cerevisiae, on the volatilome of a red wine. The wines produced with St. bacillaris biofilm-detached cells exhibited a greater concentration of glycerol and a lower quantity of ethanol than the other wines. Furthermore, these wines exhibited elevated levels of higher alcohols, organic acids, esters, terpenes, and norisoprenoids. Based on the odor activity value and relative odor contribution, isoamyl acetate, ethyl octanoate, ethyl isobutanoate, and methyl decanoate were the main aroma components of wines made with planktonic cells. The main compounds characterizing the wines obtained with biofilm-detached cells were: phenethyl alcohol, β-damascenone, citronellol, β-ionone, and nerol. The sensory analysis revealed that the wines produced with biofilm-detached cells had higher scores for mouth-feel, spicy, floral, and raspberry notes than the others. The present study provides evidence that St. bacillaris biofilm-detached cells released specific volatile compounds in red wines.

Aroma Profile of Merlot Red Wine Stored in Stainless-Steel Tanks and Wooden Barrels with Different Toasting Methods

Stainless-steel tanks and wooden barrels are the most common wine ageing and storage vessels. Wooden barrels are often toasted to improve their chemical composition and influence on wine. The aim of this study was to investigate the changes in Merlot red wine aroma from the 2020 and 2021 vintages during 12-month storage (with sampling every 3 months) in a stainless-steel tank (SST), Excellence oak barrels with medium (EMT), medium plus (EMT+) and medium long (EMLT) toasting and a Premium oak barrel with medium toasting (PMT). The results showed that even slight differences in the time and temperature of medium toasting influenced the extraction of aroma compounds from wood to wine. The changes in individual aroma compounds depended on the vessel type, toasting level, initial wine composition and storage time. An increase in the total concentration of compounds with smoky, spicy and woody notes occurred in both wine vintages stored in wooden barrels, especially during longer storage. In samples from SST, floral, fruity and herbal aromas were more pronounced, according to the gas chromatography and sensory evaluators. Sensory evaluators rated the samples according to the 100-point test, and after 12 months of storage, 2020 and 2021 vintage Merlot stored in PMT obtained the highest points.