Abstract: In this study, the effect of catalase on the transformation of aroma components in Baiyaqilan tea, a new type of oolong tea was investigated by gas chromatography-mass spectrometry (GC-MS) and odor activity value (OAV). The results showed that the types of volatile aroma components in Baiyaqilan tea changed after catalase treatment. A total of 17 and 23 components with OAV ≥ 1 were identified in Baiyaqilan tea before and after catalase treatment, respectively. Principal component analysis (PCA) performed on the aroma composition data showed a good discrimination between Baiyaqilan tea before and after catalase treatment. The OAV of aroma components such as trans-2-nonenal, linalool, trans-geranylacetone, and β-cyclocitral increased significantly after catalase treatment, while those of cis-linalool oxides decreased significantly. The changes of these components indicated that the effect of catalase on the aroma of Baiyaqilan tea was related to transformation reactions such as the oxidative decomposition of catechins, the hydrolysis of terpene alcohols, the hydrolysis of glycosidic aroma precursors, lipid oxidation, oxidative degradation of carotenoids, and oxidative deamination of amino acids. This study helps to enrich the understanding of the aroma formation of tea and provides technical references for enhancing the aroma of tea products.

Key words: tea; aroma; catalase; gas chromatography-mass spectrometry; conversion of components