Unraveling flavor formation in Jiuqu: Source pathways, influencing factors, and regulatory strategies

Jiuqu serves as the traditional fermentation starter for Chinese alcoholic beverages, primarily consisting of Daqu , Xiaoqu , and Fuqu . Its diverse flavor characteristics stem from variations in production techniques, raw materials, and environmental conditions. As the key source of flavor compounds in alcoholic beverages, Jiuqu fundamentally determines product quality. However, while the inherent open fermentation process generates flavor complexity, it simultaneously poses significant quality control challenges. To enhance alcoholic product quality and flavor stability, investigation of Jiuqu 's major flavor compounds, their formation pathways, influencing factors, and control strategies is essential. This review summarizes key flavor components across major Jiuqu varieties, identifies their primary source pathways, analyzes critical factors affecting flavor formation, and provides effective flavor regulation approaches. This review establishes a foundation for developing robust quality control measures to ensure consistency in Jiuqu production and improves traditional alcoholic beverage quality, while also providing guidelines for researchers exploring flavor regulatory mechanisms in other fermented foods.