Effect of storage time on aroma profiles of wuyi rock tea

Wuyi rock tea (WRT) is typically stored for weeks or months before consumption, and the roasted aroma changes into a floral aroma during the storage. However, little is known about the aroma change that occur during this period. The aroma in WRT during storage was extracted and identified using simultaneous distillation extraction coupled with gas chromatography mass spectrometry, in addition to calculating the odor activity value (OAV) and conducting aroma recombination experiments. The results revealed the emergence of floral aroma with increasing storage time. Alcohols, aldehydes, and aromatics were the main volatile types in WRT. According to partial least squares discriminant analysis, 20 volatiles were crucial variables contributing to the volatile differences in WRT with variations in storage time. The key volatiles causative for the overall aroma of WRT were determined based on their OAVs. In total, 25 volatiles with OAVs >1 were identified as aroma-active compounds. Notably, trans-β-ionone, 2-ethyl-3,5-dimethylpyrazine, linalool, octanal, nonanal, dehydro-β-ionone, and pentylfuran were substantial players in the overall aroma profile of WRT under storage. Based on the results of aroma combination experiments, the contribution of 18 volatiles with OAVs >2 to the overall aroma of WRT was confirmed. The findings augment our comprehension of aroma development in WRT throughout the storage.