Abstract
Pure β-carotene, as well as carotenoid extract from fresh tea leaves, was heated in a water bath of 90°C, 120°C and 150°C, which are similar to temperatures used for processing green tea. Ether extracts from the resultants were analyzed by GC-MS.
Among 40 degradation compounds, dihydroactinidiolide was present in highest concentration at the three tested temperatures. At 90°C, 5, 6-epoxy-β-ionone was the second highest, while at 150°C, 2, 6, 6-trimethyl-2-hydroxy-cyclohexanone and 2, 6, 6-trimethyl-2-hydroxy-eyclohexan-1-aldehyde (tentative) were greatly increased in quantity. At 120°C, these compounds were more evenly distributed than at 90°C and 150°C. Besides these four compounds, β-cyclocitral, β-ionone and 2, 6, 6-trimethyl-2, 3-epoxycyclohexyliden-1-aldehyde were identified as ionone ring possessing compounds, and they are all known to contribute to green tea aroma.
