Topmouth gudgeon (Pseudorasbora parva) is a small freshwater cyprinid widely distributed in China, Japan, North Korea, and other Asian countries, as well as some European countries (Chen et al., 2018).Topmouth Gudgeon is delicious, high in protein, and rich in nutritional value; in China, it is usually processed into leisure fish products, which are deeply loved by consumers (Zhu et al., 2018).Deep-fat frying is one of the most popular cooking methods in the home and in restaurants, as well as industry. It is not only efficient (Millin et al., 2016) but can also impart attractive color, texture, mouthfeel, and flavor (Li et al., 2020a). Deep-fat frying is a complex heat and mass transfer process that induces physical, chemical, and structural changes in food. During the frying process, the food absorbs heat from the hot oil, causing the evaporation of water to gradually extend from the surface to the inside. Oil then enters the food through pore channels formed by dehydration (Li et al., 2020b;Millin et al., 2016).Moisture and oil content, color, texture, and volumetric shrinkage (S v ) are essential quality parameters for fried foods, and water activity (a w ) is used to evaluate whether fried foods are safe and