Chemometrics and sensomics-assisted identification of key odorants responsible for retort odor in shelf-stored green tea infusion: A case study of Biluochun

The deterioration of aroma quality in tea beverages during the shelf life is a significant issue. In this study, sensomics techniques were employed to identify the characteristic factor contributing to aroma degradation in green tea infusion. Samples A (no/faint retort odor) and B (high intensity retort odor) were selected based on their retort-like odor intensity after heat treatment simulating shelf-life conditions. The key odorants were identified through a combination of chemometrics analysis, comparative aromatic extract dilution analysis (cAEDA), detection frequency analysis (DFA), and odor-specific magnitude estimation (OSME). Subsequently, eight odorants, including linalool (892.451 μg/L), ( E )- β -damascenone (5.105 μg/L), phenylacetaldehyde (27.720 μg/L), nonanal (2201.439 μg/L), α -terpineol (7.166 μg/L), geraniol (0.499 μg/L), theaspirane (0.044 μg/L), and 2-hydroxy-5-methylacetophenone (2.973 μg/L), were identified as the key substances contributing to the retort-like odor in sample B. Aroma recombination and omission test further demonstrated that elevated concentrations of nonanal, geraniol, phenylacetaldehyde, and theaspirane might be the primary reasons for the retort odor observed in samples.