Comprehensive analysis of carotenoids constituents in purple-coloured leaves and carotenoid-derived aroma differences after processing into green, black, and white tea

Carotenoids differentiate among tea cultivars and play role in contributing aroma flavor and colour appearance in tea products. In this study, 3 carotenes and 16 xanthophylls were accurately quantified of 0.79–1.56 × 103 μg g−1 in 15 tea cultivars possessing leaves of different colours. Lutein and β-carotene accounted for >80% of total carotenoids. Single carotenoid accumulation patterns and their correlations with chlorophylls and primary metabolites (amino acids, alkaloids, and saccharides) were elucidated. Tea processing (withering, 'kill-green,' fermentation, and drying processes) decreased tea carotenoids by >65%, promoting volatile apocarotenoid production. In total, 25 crucial carotenoid-derived aroma compounds were detected in green, white, and black teas prepared from purple shoots. Additionally, α/β-ionone and their derivates, and dihydroactinidiolide accounted for >50% of total volatiles and therefore explained the fruity aroma in purple tea products. A comprehensive integrative analysis of sensory attributes and volatile and carotenoid precursor dynamics clearly revealed patterns of tea carotenoid accumulation and degradation contribution to tea aroma.