Change in the Flavor of Black Tea Drink during Heat Processing

Heat processing during canning is responsible for the change in flavor of black tea infusion. The quantitative change in the volatile components of the black tea infusion during heat processing is not sufficient for explaining the sensory evaluation. In this study, application of aroma extract dilution analysis using the volatile fraction before and after black tea (Darjeeling) samples were heat processed resulted in the detection of 10 odor-active peaks for which flavor dilution (FD) factors changed. Seven potent odorants were identified from these peaks by gas chromatography-mass spectrometry. Among these components, 3-methylbutanal (stimulus), methional (potato-like), beta-damascenone (sweet), dimethyl trisulfide (putrid), and 2-methoxy-4-vinylphenol (clove-like) showed the highest FD factors after heat processing of the black tea sample. Therefore, these odorants were the most important components involved in changing the black tea odor during heat processing. In addition, the precursor of beta-damascenone in black tea infusion was investigated, and 3-hydroxy-7,8-didehydro-beta-ionol was determined to be one of the beta-damascenone-generating compounds for the first time.