A NEW SPECIFIC LINEAGE OF OENOCOCCUS OENI IN COGNAC APPELLATION WINES

The sensory characteristics of wine are a topic studied by several researchers over time, but it continues to be a current and challenging subject. These characteristics are fundamental for the consumer acceptability, which has increasingly aroused their interest to modulate them in line with current market trends and innovation demands. The wine physical-chemical and sensory properties depend on a wide set of factors: they begin to be designed in the vineyard and are later constructed during the various stages of winemaking. Afterwards, the wine is placed in bottles and stored or commercialized.

Kalecik Karası is a domestic grape variety of Turkey, originating from Kalecik district, 80 km from Ankara. Although there is no definite evidence, it is known that it was used in wine production by many civilizations that lived in the Anatolian region, especially the Hittites. Compared to other black wine grapes, it stands out with its low tannin content, rich fruity aroma and complex structure. In good vintages, red fruits such as strawberries, cherries and raspberries stand out in the aroma profile. Although its structure is elegant, it has the potential to age and develop similar to the ‘Pinot Noir’ wine of the Burgundy region. This offers a complex aroma structure including red flowers, earth and ripe fruits.

Measuring the effect of oxygen consumption on the colour of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine is able to consume without significantly altering its colour. The changes produced in wine after being exposed to high oxygen concen-trations have been studied by different authors, but in all cases the wine has been analysed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen.

Aging wine on lees is a consolidated practice during which some yeast components (e.g., polysaccharides,
proteins, peptides) are released and solubilized in wine thus, affecting its stability and quality.
Apart from the widely studied mannoproteins, the role of other yeast components in modulating wine
characteristics is still scarce. Wine peptides have been studied for their contribution to taste, antioxidant,
and antihypertensive potentials. However, the peptides detected in wine can be influenced by the
interaction between yeasts and grape components.

The interactions between geographical and biotic factors, along with the winemaking process, influence the composition and sensorial characteristics of wine¹. In addition to the primary end products of alcoholic fermentation, many secondary metabolites contribute to wine flavor and aroma and their production depends predominantly on the yeast strain carrying out the fermentation. Commercially available strains of S. cerevisiae help improve the reproducibility and predictability of wine quality. However, most commercial wine strains available on the market have been isolated from Europe, are genetically similar, and may not be the ideal strain to reflect the terroir of Canadian vineyards².