Insights into the Key Odorants in Large-Leaf Yellow Tea (Camellia sinensis) by Application of the Sensomics Approach

Abstract

Large-leaf yellow tea (LYT) is a yellow tea product with a specific aroma characteristic and is enjoyed with increasing enthusiasm in China. However, its key odorants are still unknown. In this study, 46 odorants in the headspace and vacuum-distillate of the tea infusion were identified via aroma extract dilution analysis. Sixteen compounds were newly found in LYT infusion. They were present in the highest flavor dilution factors together with 2-ethyl-3,5-dimethylpyrazine. All odorants were quantitated to evaluate their own odor activity values (OAVs). High OAVs were found for 2-methylbutanal (malty, 210), (E,E)-2,4-heptandienal (fatty/flowery, 170), 2-methylpropanal (malty, 120) and 2,3-diethyl-5-methylpyrazine (earthy/roasty, 110). An aroma recombinate consisting of 17 odorants (all OAVs ≥ 1) in an odorless nonvolatile LYT matrix mimicked the overall aroma of the original infusion, verifying the successful characterization of key aroma components in a LYT beverage. The knowledge of key odorants obtained showed potential for simplifying industrial flavor optimization of the LYT product.

Exploring the effect of different tea varieties on the quality of Lu’an Guapian tea based on metabolomics and molecular sensory science

“…SCZ also contained a high proportion of alcohols (28%); however, unlike the other two varieties, heterocyclics comprised 32% of the total volatile content in QTZ, whereas alcohols comprised only 15%. Most heterocyclics are reported to have a roasted odor ( Zhai et al, 2023 ); hence, the high concentration of heterocyclics is probably responsible for the relatively high score for “roasted” in QTZ.…”

Sensomics-Assisted Characterization of Fungal-Flowery Aroma Components in Fermented Tea Using Eurotium cristatum

“…Coumarin has been detected in several tea categories, including green tea, black tea, yellow tea, and oolong tea. ,− Fresh tea leaves contain glycosidic aroma precursors of coumarin, which can be hydrolyzed to release the free-from coumarins during tea processing . It is well-known that fungi can produce a large number of extracellular enzymes, in which glycosidase can promote the glycoside-binding hydrolysis of coumarin precursors. − Thus, it was speculated that the significant increase of coumarin content may result in the enhancement of flowery aroma in the FT.…”

“…Research has demonstrated that 2-methylbutanal, dimethyl sulfide, 2-ethyl-6-methylpyrazine, trimethylpyrazine, and 2-ethyl-3,5-dimethylpyrazine are the key odorants of the unique aroma in large-leaf yellow tea through aroma recombination and omission tests. 14 (E)-β-Ionone, geraniol, and (E,E)-2,4-heptadienal have been identified as the key odorants for the floral aroma properties of extra-virgin Lu'an Guapian through addition tests. 15 Many studies have been conducted on volatile compounds in fu brick tea and fermented tea by single E. cristatum, but the key odorants of fungal-flowery aroma and their key odorants are unclear.…”

“…With the development of a sensomics approach, some volatile compounds have been found to have unique aroma profiles in several types of Chinese teas, such as yellow tea and green tea. Research has demonstrated that 2-methylbutanal, dimethyl sulfide, 2-ethyl-6-methylpyrazine, trimethylpyrazine, and 2-ethyl-3,5-dimethylpyrazine are the key odorants of the unique aroma in large-leaf yellow tea through aroma recombination and omission tests .…”

Large yellow tea polysaccharides ameliorate obesity-associated metabolic syndrome by promoting M2 polarization of adipose tissue macrophages

“…Large yellow tea (LYT), a unique slightly fermented tea, is one of the six major categories of traditional tea (Camellia sinensis) processed in China which has gained increasing popularity in recent years owing to its pleasant toasty flavor and health-promoting functions, including anti-hyperglycemic, anti-hyperlipidemic, anti-inflammatory, and antiobesity. 9,10 Our previous studies reported that water extraction of LYT has remarkably attenuated macrophage-related chronic inflammation and metabolic syndrome in HFD-induced obese mice. 11 Recently, we obtained homogeneous polysaccharides (LYPs) from LYT with a known structure and a strong activity to promote the M2 polarization of macrophage in vitro cocultures.…”