## 1 Introduction  
Food flavor is one of the key attributes of food and plays a decisive role in consumer preference. Currently, the flavor research of distilled spirits mainly focuses on its objective aroma composition, while little attention is paid to its flavor performance during the eating and drinking process [1]. For example, for distilled spirits, such as brandy and vodka, adding ice and mixing cocktails will affect consumers' flavor perception. However, when it comes to baijiu, the national liquor of China, consumers mostly choose to drink it neat and pair it with food. Peanut is the most common accompanying food. Baijiu is made from various grains through microbial fermentation, distillation, blending, and aging [1]. Its aroma substance composition is extremely rich, and more than 3000 flavor substances have been discovered so far [2]. Rich aroma and long aftertaste are the typical flavor characteristics of baijiu. The aftertaste involves a complex oral processing process, which has not been fully studied so far. In the previous stage, we found that, in the baijiu-peanut pairing, peanuts can selectively affect the release pattern of baijiu flavor substances in the oral cavity, bringing the possibility of regulating the aftertaste of baijiu [2; 3]. Nearly half of the peanut components are lipids [4]. Together with water and ethanol, they are the food components that most significantly affect the release intensity of flavor compounds [5]. In the baijiu-peanut system, these three major influencing factors coexist, and their combined effect on the release of baijiu flavor is worthy of in-depth exploration [6]. Most of the flavor substances in baijiu are polar compounds with lipophilicity. Lipids can significantly change their release intensity [7]. Under the influence of lipids, the release intensity of octanoic acid and \(\gamma\)-decalactone is reduced by 60 times, and the threshold of 2,4-decalenal is increased by 600 times [8]. In the oral environment, lipids can also significantly affect the flavor performance of compounds. [PERSON] found that the reduction in lipid content in the oral environment can promote the release intensity of compounds such as alcohols, ketones, esters, aldehydes, terpenes, and sulfur-containing compounds, and the degree of influence is related to the type and chain length of the compounds [9]. Lipids and aroma compounds can interact through hydrophobic interaction forces, van der Waals forces, hydrogen bonds, etc., thus affecting the volatilization process of substances [7]. In the dynamic process, the influence of lipids on food flavor is more obvious [6]. The lipid content of food will not only affect the perceived intensity but also the time distribution of flavor. Researchers have found that when eating lipid-containing food, lipids or lipid substances can form an oral coating on the tongue under the pressure of the tongue on the soft palate, affecting the aftertaste of the food [10]. The barrier formed by the oral coating limits the access of taste substances to taste receptors. For volatile flavor substances, they must first be released from the lipid-containing system before they can enter the headspace to form retronasal aroma. Therefore, lipid-soluble compounds are perceived later than water-soluble compounds [11]. Studies on the surface of the pig tongue have found that the amount of residual food on the oral surface will increase with the increase in fat content [12]. The fat in cheese forms an oral coating that can delay the transfer of aroma compounds and slow down their release in the aftertaste, so that the flavor substances are slowly released in the post-swallowing stage, prolonging their flavor perception [13]. The oral coating formed by peanut lipids during the eating process may be one of the main ways that peanuts affect the aftertaste of baijiu. Ethanol is an important matrix component in baijiu and is a special food matrix that distinguishes the flavor research of alcoholic beverages from other foods.