## 1 Introduction  
Yeast assimilable nitrogen (YAN), composed of organic (amino acids) and inorganic (ammonium ions) forms, is an important macronutrient involved in yeast metabolism [1]. Their concentrations vary depending on variety, geographical location, climate, and viti-culture practices [2; 3]. During alcoholic fermentation, YAN is used to sustain growth and produce biomass as well as synthesize fermentative aroma compounds [4]. Esters are the major fermentative aroma compounds, and they can impart aroma even at concentrations below their odor threshold [5]. Fruity esters, including acetate esters and fatty acid ethyl esters (FAEEs), are considered target components to enhance wine aroma [6]. Studies on the correlation between amino acids and aroma compounds have revealed an association between amino acids and fruity ester production [7; 8; 9]. Amino acid supplementation in grape must enhanced the production of fermentation-derived aroma components, such as acetate esters and ethyl esters [10; 11; 12] and improved the scores for the descriptors \"confectionary\", \"red fruit\", and \"dark fruit\" [13]. These findings suggest that amino acid supplementation potentially improves wine aroma quality. The synthesis of fermentation-derived aroma compounds as well as their association with nitrogen and sugar metabolism in _Saccharomyces cerevisiae_ has been extensively studied. \(\alpha\)-keto acids have been considered as important intermediaries in the formation of higher alcohols and volatile acids. Either amino acid catabolism via the Ehrlich pathway [14] or glucose/fructose metabolism via central carbon metabolism [15] produces these precursors. Nevertheless, mechanisms underlying the increase in fruity esters under amino acid supplementation are still not clearly understood. Recent studies have shown that only a small fraction of higher alcohols is produced by catabolism of consumed amino acids [16; 17]. The interaction between central carbon metabolism and nitrogen metabolism may significantly influence the production of volatile compounds in _S. cerevisiae_[2]. Traditionally, nitrogen was supplemented without the determination of amino acid content of grape must. Injudicious supplementation of nitrogen is wasteful and has negative impacts on wine aroma due to high acetic acid and ethyl acetate production [4]. Therefore, several studies have highlighted the need to determine the nutritional status of grape juice before nitrogen supplementation to increase aromatic compound production by yeast [11; 18]. Further studies are necessary to evaluate the increase in wine aroma and explore the possible mechanisms of increase in fruity esters under goal-directed amino acid modulation. Spine grape is a wild species widely distributed in southern China. Spine grape wine has high anthocyanin and polyphenol content [19] with poor fruity aroma. A study has shown that spine grape wine has weak aroma characteristics, which may be related to low levels of varietal aroma precursors and fermentative aroma compounds. In particular, fruity esters were positively correlated with wine fruity aroma [20]. On the contrary, Cabernet Sauvignon, a well-known _Vitis vinifera_ grape, has elegant fruity aroma with high fruity ester content. Variations in the ester profiles of Shiraz and Cabernet Sauvignon wines were related to specific grape-juice nitrogen composition [21], and our previous study also indicated the significant correlation between amino acid composition and fruity ester production during fermentation of spine grapes [22]. Therefore, modulation based on the amino acid profile of Cabernet Sauvignon can be an effective approach to increasing the fruity ester content of spine grape wine. In this study, we attempted to enhance the fruity ester content in spine grape wine by goal-directed amino acid supplementation. [PERSON]'s correlation was used to describe the association between amino acid profile and fruity ester content in spine grape and Cabernet Sauvignon grape during fermentation.