Effects of Drying Methods on Flavor Substances and Identification of Characteristic Flavor Compounds of Dried Tangerine Peel.

Drying method is a key factor influencing the nutritional quality and flavor characteristics of Chenpi. In this study, peels of Citrus reticulata 'Chachi' (Xiaoqinggan) were subjected to natural air drying (NAD), hot-air drying (HAD), and vacuum drying (VD) to evaluate changes in physicochemical properties, free amino acids, and volatile compounds. VD exhibited superior retention of total flavonoids and soluble sugars, resulting in the best overall physicochemical quality. NAD preserved the highest total free amino acid content and amino acid diversity, whereas HAD was characterized by a predominance of bitter amino acids, contributing to a pronounced bitter taste. In contrast, VD maintained a more balanced amino acid composition with relatively high proportions of sweet amino acids and effective retention of aroma precursors. A total of 75 volatile compounds were identified by GC-MS, with olefins representing the dominant class. NAD exhibited the highest total volatile content, while VD retained the greatest diversity of volatile compounds and a more balanced aroma composition. Odor activity value (OAV) analysis revealed that key aroma-active compounds were effectively preserved in VD-treated samples, with linalool identified as the major contributor to citrus peel aroma. Overall, VD achieved the most favorable balance between nutritional quality, taste characteristics, and aroma preservation. These findings provide scientific guidance for optimizing drying technologies and improving the quality of Chenpi products.