Change in the Flavor of Black Tea Drink during Heat Processing

Abstract

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.

Formation of damascenone derived from glycosidically bound precursors in green tea infusions

“…From a chemical point of view, glycosylated volatile compounds enhance water solubility and decrease reactivity compared with their free aglycone counterparts. It was proposed that the precursors of damascenone in the black tea infusions have a close relationship to the aglycons released from the glycosides during the manufacturing of black tea leaves (Kumazawa & Masuda, 2001). In the present study, (3S, 9R)-1a (89 lg), (3R, 9R)-2a (16 lg), and (3R, 9R)-2b (0.45 lg) were isolated and identified in green tea infusions (100 g of water extract) based on the evidences of HPLC-MS and NMR ( Fig.…”

“…In addition to Bulgarian rose (Rosa damascena) oil, where it was firstly identified (Demole, Enggist, Säuberli, Stoll, & Kováts, 1970), damascenone or its precursors are found in other natural products such as tomatoes (Buttery, Teranishi, & Ling, 1987), apples (Roberts, Morehai, & Acree, 1994), grapes (Shure & Acree, 1994), and in plant-derived beverages such as beers (Chevance, Guyot-Declerck, Dupont, & Collin, 2002), wines (Kotseridis, Baumes, & Skouroumounis, 1999), and black teas (Kumazawa & Masuda, 2001). Several glycoconjugates of the two polyol precursors of damascenone, 9-O-b-D-glucopyranosyl-megastigma-6,7-dien-3,5,9-triol (1a), 3-O-b-D-glucopyranosyl-megastigma-6,7-dien-3,5,9-triol (1b), 9-O-b-D-glucopyranosyl-3-hydroxy-7,8-didehydro-b-ionol (2a), and 3-O-b-D-glucopyranosyl-3-hydroxy-7,8-didehydro-b-ionol (2b), have been isolated from various plant tissues such as Lycium halimifolium (Näf, Velluz, & Thommen, 1990), apples (Roberts et al, 1994), R. damascena Mill.…”

“…Damascenone was determined as one of the most important odour components of Japanese green tea (Sencha) products (Kumazawa & Masuda, 1999), and increased in concentration during the processing of black tea infusions (Kumazawa & Masuda, 2001). Although it was proposed that precursors of damascenone in the black tea infusions may be glycosides of 3-hydroxy-7,8-didehydro-b-ionol (2) by enzymatic reaction from a crude glycoside fraction obtained from green tea infusions (Kumazawa & Masuda, 2001), the chemical structure was not completely elucidated.…”

Aroma formation in Dianhong black tea: Effects of baking

“…One of the many contributory factors to its high acceptability is its flavour. [1,2] Dianhong tea is one of the most well-known black teas from China, and is produced by using two leaves and a bud from the Yunnan broad-leaf tea variety as raw materials. It is plucked, withered (partially desiccated), rolled, fermented, dried, and, finally, baked.…”

“…These results indicated that the relative content of each aroma compound could greatly affect the aroma quality. Kumazawa et al [1] used the volatile fraction obtained before and after the heat processing of the black tea samples and detected 10 odouractive peaks for which the aroma dilution factor changed. These odourants were the most important components involved in changing the black tea odour during heat processing.…”