Integrated analysis of dynamic changes in volatile and non-volatile compounds in Chuan Chenpi (Citrus reticulata ‘Dahongpao’) during aging by GC-IMS and UPLC-MS/MS

Chuan Chenpi (CCP), the peel of the ancient Chinese citrus variety Citrus reticulata ‘Dahongpao’, enhances its edible and medicinal value through aging. This study focuses on CCP samples aged 1–8 years, aiming to explore the dynamic changes during aging. Although aging induced noticeable changes in color, Fourier Transform Infrared (FTIR) analysis revealed no significant alterations in functional groups. Volatile and non-volatile metabolomic analyses indicated that aging primarily affects metabolite content rather than types, and both composition and antioxidant activity reached relatively high levels in the fourth year. The experimental results illustrate that the improvement in CCP quality induced by aging does not follow a linear pattern but exhibits fluctuations. The findings verify that the fourth year serves as a critical turning point for CCP's quality. This study clarifies the dynamic variation of chemical components in CCP during aging, thereby providing a scientific basis for the selection of its aging duration. • Notable alterations in color were observed throughout the Chuan Chenpi (CCP) aging process. • Minor change in compound types but significant change in concentrations during aging. • The effect of aging on improving the quality of CCP does not increase linearly. • The fourth year of aging represents a critical turning point for the quality changes of CCP.