## 1 Introduction  
Aroma is a crucial quality indicator in wine [1]. Currently, over 1300 volatile compounds have been identified in wine, including alcohols, esters, aldehydes, ketones, acids, terpenes, norisoprenoids and sulfur-containing compounds, with concentrations ranging from \(\mu\)g/L to mg/L [2; 3; 4]. These compounds are typically categorized as varietal aroma, fermentation aroma and aging aroma based on their respective sources [5]. Varietal aroma in wine is primarily contributed by grape berry-derived aroma compounds, such as terpenes, and norisoprenoids, etc., [6]. These compounds play a crucial role in determining the typicality of wine in terms of its variety and region. Their composition and concentration are influenced by both the genotype and the grape-growing environment. Fermentation-derived aroma compounds include alcohols, esters, aldehydes and volatile fatty acids, which are produced by yeast during alcohol fermentation and by lactic acid bacteria during maloalactic fermentation, using flavor precursors from grape berries as substrates [7; 8]. Therefore, aroma compound profile in grape berries plays an important role in the formation of wine aroma quality. Aroma compounds exist mainly in grape skins with both free and glycosylated bound forms. The leaching of these compounds and their precursors from grapes and their subsequent conversion in fermentation broth are significantly affected by the cold soak process before fermentation, as well as various microorganisms and grape must components during fermentation [9; 10; 11; 12; 13]. It is important to note that per-fermentation cold soak is an aqueous system. Previous studies have primarily focused on the effects of cold soak technology on the color appearance and phenolic compounds of wine [14; 15], with little attention given to aroma compounds. According to research, cold soaking can destroy the cell membrane by increasing liquid volume in grape cells, which leaches aroma compounds [16]. This process can improve the richness of the original fruity aroma of wine and enhance the wine body [17]. Many reports have focused on the effects of fermentation technology on wine aroma production. Recent studies have shown that the interaction between phenolic compounds, polysaccharides, and aroma compounds in fermentation broth has garnered significant attention. It has been found that polyphenols and polysaccharides can influence the volatility of aroma compounds, such as terpenes and esters, through intermolecular interaction forces like hydrogen bonding, dispersion force, and \(\pi\)-\(\pi\) stacking [13; 18]. Furthermore, the presence of ethanol in the wine matrix can alter the conformation of proteins, ultimately affecting the binding of protein and aroma molecules [4]. Overall, the release and retention of aroma are influenced by the wine matrix to varying degrees. However, the impact of the matrix on the extraction, conversion, and generation of new aroma compounds during the cold soak and fermentation stages remains unclear. Understanding the similarities and differences in the leaching and conversion of aroma compounds between different varieties is helpful in guiding the production of high-quality wine. To date, most studies on the evolution of aroma compounds during fermentation and aging have focused on specific winemaking phases rather than the entire process. Additionally, studies have only concerned free aroma compounds that have direct sensory contribution to wine. During fermentation and aging, glycosidically bound aroma compounds from grapes can be hydrolyzed into the corresponding free-form glycones. This process has the potential to significantly contribute to the aroma quality of the final wine. However, there is limited understanding of the changes that occur to these bound compounds during wine fermentation, particularly at an industrial scale.