Analysis of chemical components in oolong tea in relation to perceived quality

Wang, Kunbo; Liu, Fang; Z, Liu; Huang, Jianan; Zhong-xi, XU; Li, Yinhua; Chen, Jinhua; Gong, Yushun; Yang, Xinghe

doi:10.1111/j.1365-2621.2010.02224.x

Cited by 50 publications

(48 citation statements)

References 25 publications

(51 reference statements)

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“…OAV analysis showed that octanal, 2‐pentyl‐furan, trans‐ nerolidol, benzene acetaldehyde, and 2‐ethyl‐furan had high OAV values in the NIOT sample (Table ). This phenomenon was consistent with a previous study that the chemicals such as nerolidol and phenyl acetaldehyde were the characteristic aroma compounds of Oolong tea (Wang et al, ). Besides, the OIOT showed higher OAVs of β ‐trans‐ damascenone (OAVs of 22,543.7 vs. 0.0) and octanal (OAVs of 59,529.0 vs. 31,294.1) than the NIOT (Table ), which might explain why the OIOT had much stronger intensities of sweet and fruit notes (Table ), since these chemicals possess honey‐like and fruity notes (Zhu et al, ).…”

Section: Resultssupporting

confidence: 93%

“…The NIOT and OIOT had 28 and 23 volatiles detected (Table ), respectively. Specifically, trans‐ nerolidol (10,660.7 μg/ml), indole (4,778.1 μg/ml), α ‐ farnesene (4,507.8 μg/ml), phenyl acetaldehyde (2,034.0 μg/ml), hexanal (1,986.9 μg/ml), and 2 ‐ pentyl‐furan (1,403.1 μg/ml) had higher concentrations than other volatiles in the NIOT (Table ), which was consistent with the previous report that nerolidol, indole, benzene acetaldehyde, linalool, linalool oxide, hexanal, benzyl nitrile, and geraniol were the prevailing volatile compounds in Oolong tea (Wang et al, ). The main volatile constituents of OIOT were 3,5‐dimethyl‐phenol (668.5 μg/ml), 3,7‐dimethyl‐1,5,7‐octatrien‐3‐ol (482.9 μg/ml), 2‐methyl‐furan (479.9 μg/ml), and octanal (416.7 μg/ml).…”

Section: Resultssupporting

confidence: 80%

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Characterization of aromas of instant oolong tea and its counterparts treated with two crude enzymes from Aspergillus niger

Zhang

Zhu

et al. 2017

J Food Process Preserv

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Sensory evaluation, GC–MS and omission test were used to characterize aromas of noninstant Oolong tea (NIOT), original instant Oolong tea (OIOT) and its counterparts treated by two enzyme extracts from Aspergillus niger. The results showed that OIOT had stronger sweet, fruity, and roasted notes, but weaker grass and floral notes than NIOT. After treated by the crude enzymes extracted from the fermented broth from tea waste (TW) medium, the treated‐OIOT had an improved aroma similar to that of NIOT, due to the increases of 2‐pentyl‐furan and 3‐cis‐hexen‐1‐ol. In comparison, after the treatment of crude enzymes from wheat bran and orange peel (WBOP) medium, the treated‐OIOT showed significantly aroma difference from NIOT and OIOT, which was attributed to the increases of 3‐cis‐hexen‐1‐ol, γ‐terpinene, and β‐trans‐farnesene. These results revealed that the original aroma of OIOT could be effectively modified and improved by the enzyme extracts, particularly by that from the TW medium. Practical applications Tea is one of the most popular beverages all over the world. Instant tea is an important tea product that is processed from teas by extraction, concentration and drying. Instant tea is more convenient than teas for industrially producing tea foods such as tea beverage, tea break, and tea ice cream. However, the aroma profile of instant tea is always inferior to those of the original unprocessed noninstant teas, because the characteristic aroma of the original unprocessed tea could undergo significant changes during the preparation of instant tea. The present manuscript shows two enzyme extracts from Aspergillus niger could improve the aroma of instant Oolong tea, providing interesting information to promote the aroma of instant tea via enzymatic treatments, which may help to develop effective approaches to enhancing the quality of instant teas.

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Section: Resultssupporting

confidence: 93%

Section: Resultssupporting

confidence: 80%

Characterization of aromas of instant oolong tea and its counterparts treated with two crude enzymes from Aspergillus niger

Zhang

Zhu

et al. 2017

J Food Process Preserv

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“…Linalool and nonanal have been characterized as aroma-active compounds contributing to floral or fruity odors in Longjing tea infusions (Table 2), and linalool has a high flavor dilution (FD) factor ≥100 (Kumazawa and Masuda, 1999;Cheng et al, 2008). Furthermore, they were also reported to have significant positive correlation with the perceived aroma of Longjing tea or oolong tea (Wang and Ruan, 2009; Wang et al, 2010). Safranal was also characterized as an herbal odorant in green tea (Zhu et al, 2008) and Pu-erh tea (Lv et al, 2012).…”

Section: Volatile Compounds and Perceived Aroma Qualitymentioning

confidence: 94%

Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

Lin

Dai

Guo

et al. 2012

J. Zhejiang Univ. Sci. B

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Abstract:This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compounds could be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized, representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (−0.785), and β-ionone (−0.763). On the basis of these 10 compounds, a model (correlation coefficient of 89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjing tea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MS technique.

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“…Polyphenols are widely used for prophylaxis and treatment of a variety of disorders. Lipid is also necessary though lipids are not major constituents in a tea brew but they can play an important roles in the development of aroma (Bhuyan et al 1989, Hara et al 1995, Scharbert and Hofmann 2005, Wang and Ruan 2009 and has an impact on nutritional profile of tea. however, there is no absolute measurement of caffeine, polyphenol and crude fat content of the released BT varieties.…”

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confidence: 99%

Caffeine, Polyphenol and crude fat contents in tea varieties available in Bangladesh

et al. 2014

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The total caffeine content in Bangladesh Tea (BT) varieties (BT1-BT18) ranged from 1.59 ± 0.155 -4.15 ± 0.399 g/100g of DM and the crude fat content in BT varieties varied from 6.69 ± 0.64 -9.87 ± 0.9509 g/100g of dry material (DM). In this study, the highest amount of caffeine (4.15 ± 0.399 g/100g DM) was found in BT-16 variety (p < 0.05) while the highest amount of crude fat (9.24 ± 0.889g/100g DM) was found in BT 10 variety (p > 0.5). The total polyphenol content ranged:8.66 ± 0.831 -14.89 ± 1.432 GAE; g/100 g DM. The highest amount of polyphenol was found in BT 9 variety (14.890 ± 1.432 GAE; g/100 g DM) (p < 0.05). IntroductionCaffeine and polyphenols are the predominant factor for assuring the quality of tea (Camellia sinensis L. Kuntze) leaf (Chen 1999). Caffeine (1,3,7-trimethylxanthene) is bitter, white crystalline purine derived alkaloid that acts as a stimulant drug ( Eggers et al. 2001) and is a diverse group of compounds that are found primarily in plants and contain basic nitrogen ( Barone et al. 1996;Frary et al. 2005). Among the alkaloids probably the most physiologically active constituent is caffeine being principal representative at a level of 1 -5% of its dry weight (Stagg and Millin 1975). It is the most powerful xanthine, in its ability to increase alertness, put off sleep and to improve attention. It also acts as a vasodilator (relaxes the blood vessels) as well as a diuretic (increase urination) (Bolton 1981).The polyphenols ( Mukhtar et al. 2000) in tea mainly include flavanols, hydroxyl-4-flavanols, anthocyanins, flavones and phenolic acids which have a synergestic effect involving caffeine to (Stagg and Millin 1975) contribute the bitterness, astringency and sweetness of tea ( Hara et al. 1995). Polyphenols are widely used for prophylaxis and treatment of a variety of disorders. Lipid is also necessary though lipids are not major constituents in a tea brew but they can play an important roles in the development of aroma (Bhuyan et al. 1989, Hara et al. 1995, Scharbert and Hofmann 2005, Wang and Ruan 2009 and has an impact on nutritional profile of tea. however, there is no absolute measurement of caffeine, polyphenol and crude fat content of the released BT varieties. By analyzing caffeine, polyphenols and crude fat of these BT varieties, we can understand which variety is better in comparison with other varieties in order to improve agronomical characteristics through gene isolation, biotechnology, breeding and other allied fields. It will help the tea consumers to find the best quality tea from a very early civilization in relation to their financial ability (Islam et al. 2005, Choudhury 2010 as the tea consumers have a demand. Hence, the objective of the study is to evaluate the amount of caffeine, polyphenol and crude fat content of BT varieties to understand which BT variety is better in comparison with other varieties for cultivation and commercialization.

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Analysis of chemical components in oolong tea in relation to perceived quality

Cited by 50 publications

References 25 publications

Characterization of aromas of instant oolong tea and its counterparts treated with two crude enzymes from Aspergillus niger

Characterization of aromas of instant oolong tea and its counterparts treated with two crude enzymes from Aspergillus niger

Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

Caffeine, Polyphenol and crude fat contents in tea varieties available in Bangladesh

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