Analysis of Volatile Flavor Components in White Tea with Different Storage Durations Based on GC-IMS Technology

In order to compare the effects of storage duration on the volatile flavor components of white tea, gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze Fuding white tea stored for 1, 2, 4, 6 and 8 years. A total of 45 volatile substances were identified in the samples, including 21 aldehydes, 8 alcohols, 6 esters, 6 ketones, 2 acids and 2 heterocycles compounds. During the storage process, the aroma of white tea changed significantly, with fresh, tender, and floral notes gradually diminishing, while aged aromas became more prominent.Distinct differences in volatile compounds were observed among the samples from different storage durations, with some compounds exhibiting clear trends. The content of linalool, oxidized linalool, methyl salicylate, benzaldehyde, 6-methyl-5-hepten-2-one and other substances gradually decreased or even disappeared with the increase of storage time. In white tea stored for 1 year, (E, E)-2,4-heptadienal was significantly higher than other white teas. In white tea stored for 8 years, acetic acid, 3-methylbutanal, 2-methylbutanal, hexanal and isobutyraldehyde were abundant and their content was much higher than other white teas. These compounds are likely formed or enriched during the aging process. GC-IMS technology enables the rapid differentiation of volatile substances in white tea with different storage durations, providing a nnovel approach for the rapid identification of aged white tea.