## 3 Results and Discussion
### Free Fatty Acid Composition
Linoleic and linolenic acids participate in the lipoxygenase-hydroperoxide lyase pathway, where they serve as precursors for the synthesis of aldehydes and alcohols with six carbons [28]. In addition, alcohols, esters, aldehydes, as well as linoleic and linolenic acids, are involved in the production of volatile thiols. These volatile thiols are responsible for carrying varietal aromas and contribute to the tropical notes in the aroma of wine [29]. The importance of unsaturated fatty acids from grape skin is also manifested in anaerobic conditions in fermentation because fermentation suppresses the yeast's fatty acid desaturation. The alternative option is the direct uptake ofunsaturated fatty acids from grape juice. The addition of oxygen at the end of the growth phase can regulate the process of alcoholic fermentation and promote the synthesis of sterols and UFAs [30]. UFAs are crucial for yeast adaption to fermentation stress and fluidity of membranes, especially one from grapes because in the beginning the biosynthesis of fatty acids can be inhibited by a high content of sugar [31]. Increasing the incorporation of UFAs into yeast cell walls can enhance yeast biomass and provide valuable support during fermentation stresses, such as high sugar levels and ethanol toxicity [32; 33]. However, further research is necessary to investigate how different yeast utilize lipids from the 'Marastina' grape and their effect on the volatile profile of wine for a better understanding of potential aroma improvement. Triterpenoid, Glycerolipid, Glycerol phospholipids, Sphingolipid, and Free Fatty Acid Esters Composition  
Plants are known for their abundant production of specialized metabolites that fulfil specific roles in adaption to environmental conditions. Indeed, triterpenoids are a prominent subclass of specialized metabolites that play crucial roles in plant defence mechanisms [34]. They are formed from squalene molecules. Oleanolic acid is a pentacyclic triterpenoid and is the most abundant compound in the lipid profile of 'Marastina' grape skin (170.15-257.82 ug/g of FW) (Table 1) without statistical differences among observed vineyards. The concentration in the grape skin of white and red varieties was much lower (38.63-57.58 ug/g of FW) than in the 'Marastina' variety [2]. Oleanolic acid is a survival factor for yeast cells in conditions with a lack of oxygen and increases the biomass of yeast cells [35]. This presence of this component, unaffected by vineyard, is a notable characteristic of the 'Marastina' variety. It is possible that oleanolic acid plays a crucial role in facilitating the survival of the natural microbiota and contributing to the successful completion of the spontaneous fermentation process, as reported in a previous study [36]. Glycerolipids are mono-, di-, and trisubstituted glycolysis and represent a large group of biological molecules in plant cells acting as structural and signaling molecules in intracellular processes. The only glycerolipid found in grape skin is 1-linoleoyl-rac-glycerol in a concentration between 1.24 to 3.28 ug/g of FW. 'Marastina' grape skin is characterized by a higher concentration of 1-linoleoyl-rac-glycerol than other white varieties such as Airen and Bobal Blanc [2]. Glycerolipids have been acknowledged as a compound group that exhibits elevated levels in grapes cultivated under higher sunlight exposure, which is related to the vineyards M7, M8, and M9 because they had the highest concentration. [PERSON] and coworkers reported the impact of low and high light, where high light led to the increase in ceramides, triacylglycerols, and glycerophospholipids at a mature stage [8]. In a similar situation as with free fatty acids, the M6 vineyard, situated at a higher altitude, is characterized by the lowest concentration of glycerolipids (1.24 ug/g of FW) and glycerophospholipids (0.49 ug/g of FW). One of the primary structural constituents of yeast membranes is glycerophospholipids. They are involved in membrane fluidity and signal transduction [37].