Carotene aroma precursor

The main components of tea are essential oil (0.5%) which is formed during fermentation, caffeine (1.8%-5.0%), and tannins (13%-18%). Enzymatic formation of black tea aroma follows biosynthetic pathways. The main precursors are amino acids and carotenoids (P-carotene, lutein, neoxanthin, and violaxanthin). Fermentation significantly reduces carotenoids and forms ionone and terpenoid carbonyls as a result of primary oxidations. During firing, secondary epoxida-tion takes place and forms epoxyionone, dihydroactinidiole, and trimethyl substituted cyclohexanones [35]. 

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