Changes in volatile compounds upon aging and drying in oolong tea production

Kuo, Ping Chung; Lai, Yan; Chen, Yingjie; Yang, Wei; Tzen, Jason T. C.

doi:10.1002/jsfa.4184

Cited by 40 publications

(24 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Comparing the results of other studies, a total of 36 compounds mare tentatively identified using agreement with their mass spectra in fresh Oolong tea (Kuo et al, 2011), more than 70 volatile flavor compouds are detected in Dongding Oolong (Wang et al, 2008); 52 compounds are identified from the brewed extract and 100 compounds from the SDE of Huang Chin Kuei, respectively. 49 compounds were identified from the brewed extract of Chan Pin Oolong (Kawakami et al, 1995); and Wang has reported that nerolidol, indole, benzene acetaldehyde, linalool, linalool oxides, hexanal, benzyl nitrile, (E)-geraniol and 1-penten-3ol are the prevailing volatile compounds detected in most of Oolong tea samples.…”

Section: Resultssupporting

confidence: 61%

“…Identification and quantification of volatile composition in Rock tea infusion The aroma constituents of various tea products are interesting research topics with potential commercial values and have been continually investigated. The first scientific studies were performed more than 70 years ago (Yamanishi and Kobayashi, 1999), leading to the identification of linalool, geraniol and (Z)-3-hexenol in the volatile fractions of the tea leaf and beverage (Kuo et al, 2011). In our study, the GC/MS min to 240℃, and hold for 5 min.…”

Section: Resultsmentioning

confidence: 94%

See 1 more Smart Citation

Identification of the Different Aroma Compounds between Conventional and Freeze Dried Wuyi Rock Tea (Dangui) using Headspace Solid Phase Microextraction

Tan

Li²,

Chen³

et al. 2013

FSTR

View full text Add to dashboard Cite

Wuyi rock tea, a kind of semi-fermented Oolong tea, is produced around Wuyi Mountain. Due to its unique aroma and taste, namely the aroma of flowers and the earthy taste of rocks (hence its name as Wuyi rock tea), it has become very popular in China. Its characteristics are associated with the manufacturing processes. During which many compounds are produced. Nonvolatile compounds contribute to the taste, while volatile compounds contribute to the aroma. In this study, volatile compounds from two samples using different drying methods were extracted using headspace-solid phase microextraction (HS-SPME) approach, and then analyzed, compared and identified with gas chromatography-mass spectrometry (GC-MS). Among the volatile compounds, trans-nerolidol, farnescene, hexyl hexanoate, indole and geraniol were identified, and found to have high content in both samples. The analytical results showed that freeze drying process is an alternative drying method, which is especially suitable for the production of highly scented Wuyi rock tea.

show abstract

Section: Resultssupporting

confidence: 61%

Section: Resultsmentioning

confidence: 94%

Identification of the Different Aroma Compounds between Conventional and Freeze Dried Wuyi Rock Tea (Dangui) using Headspace Solid Phase Microextraction

Tan

Li²,

Chen³

et al. 2013

FSTR

View full text Add to dashboard Cite

show abstract

“…The variables that explained maximum variance in the data had high contributions and were considered important in discriminating samples between oolong tea and other types of teas. Benzylalcohol (V13), linalool oxides (V19, V20, V25, and V26), safranal (V30), indole (V39), β -ionone (V61), and hexadecanoic acid methyl ester (V87), which contributed to the fruity and flower-like aroma, had high positive values in oolong tea and were thought to enhance their aroma flavor (Kuo et al 2011 ). These volatile compounds in oolong tea reached their highest levels during semi-fermentation (Wang et al 2001 ).…”

Section: Resultsmentioning

confidence: 99%

Oolong tea made from tea plants from different locations in Yunnan and Fujian, China showed similar aroma but different taste characteristics

Wang

Lv²,

et al. 2016

SpringerPlus

View full text Add to dashboard Cite

Consistent aroma characteristics are important for tea products. However, understanding the formation of tea aroma flavor and correspondingly proposing applicable protocols to control tea quality and consistency remain major challenges. Oolong tea is one of the most popular teas with a distinct flavor. Generally, oolong tea is processed with the leaves of tea trees belonging to different subspecies and grown in significantly different regions. In this study, Yunnan and Fujian oolong teas, green tea, black tea, and Pu-erh tea were collected from major tea estates across China. Their sensory evaluation, main water-soluble and volatile compounds were identified and measured. The sensory evaluation, total polysaccharide, caffeine, and catechin content of Yunnan oolong tea was found to be different from that of Fujian oolong tea, a result suggesting that the kinds of tea leaves used in Yunnan and Fujian oolong teas were naturally different. However, according to their aroma compounds, principal component analysis (PCA) and cluster analysis (CA) of the volatile compounds showed that the two types of oolong teas were similar and cannot be clearly distinguished from each other; they are also different from green, black, and Pu-erh teas, a result indicating that the same oolong tea processing technology applied to different tea leaves results in consistent aroma characteristics. The PCA analysis results also indicated that benzylalcohol, indole, safranal, linalool oxides, β-ionone, and hexadecanoic acid methyl ester highly contributed to the distinct aroma of oolong tea compared with the other three types of teas. This study proved that the use of the same processing technology on two kinds of tea leaves resulted in a highly consistent tea aroma.

show abstract

“…Actually, the term ‘tea fermentation’ in this context refers to natural browning reactions induced by oxidative enzymes in the cells of tea leaves (Kuo et al, 2011). The effect of tea fermentation on antioxidant properties of IOSC are shown in Table 3.…”

Section: Resultsmentioning

confidence: 99%

The effect of tea fermentation on rosmarinic acid and antioxidant properties using selected in vitro sprout culture of Orthosiphon aristatus as a model study

Hunaefi

Smetanska

2013

SpringerPlus

View full text Add to dashboard Cite

Orthosiphon aristatus, an Indonesian medicinal plant, is normally used as a traditional herbal tea. Recently, this plant has begun to attract attention due to its antioxidant properties. However, little is known about tea fermentation effect on antioxidant properties of this plant. Thus, to extend the tea fermentation study, in vitro sprout culture of this plant was established as a new feature model. This model plant was selected based on three reasons. Firstly, as a native tropical plant, to grow this plant in sub-tropic area is considered difficult. Secondly, the in vitro sprout culture is more genetically stable compared to other types of in vitro cultures. Thirdly, results showed that this in vitro sprout culture grew faster and produced higher biomass than in vitro tissue culture. Both characteristics are important in producing tea leaves. Accordingly, the aim of the current study was twofold. First was to establish high rosmarinic acid line of in vitro sprout culture of Orthosiphon aristatus by elicitation. Second was to evaluate the effect of tea fermentation on antioxidant properties of this plant. Results showed that yeast extract (5 g/L) elicitation resulted in the highest production of rosmarinic acid. This elicited plant was subjected to partial and full tea fermentation. Results revealed that both tea fermentations decreased the level of rosmarinic acid, total phenolic compounds, flavonoids, and flavonols. These decreases were concomitant with reduced antioxidant activities as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, Trolox equivalent antioxidant capacity (TEAC), and Superoxide dismutase (SOD)-like activity assays. HPLC results showed that the longer the tea fermentation was, the greater reduction rosmarinic acid was found. High correlation value of 0.922 between rosmarinic acid and antioxidant activities was also observed. These results indicated that rosmarinic acid is the major contributor to the antioxidant activities of Orthosiphon aristatus. These results may provide useful information, in particular, for the food and pharmaceutical industries in the development of functional foods desiring maximum potential health benefits from Orthosiphon aristatus.

show abstract

Changes in volatile compounds upon aging and drying in oolong tea production

Cited by 40 publications

References 15 publications

Identification of the Different Aroma Compounds between Conventional and Freeze Dried Wuyi Rock Tea (Dangui) using Headspace Solid Phase Microextraction

Identification of the Different Aroma Compounds between Conventional and Freeze Dried Wuyi Rock Tea (Dangui) using Headspace Solid Phase Microextraction

Oolong tea made from tea plants from different locations in Yunnan and Fujian, China showed similar aroma but different taste characteristics

The effect of tea fermentation on rosmarinic acid and antioxidant properties using selected in vitro sprout culture of Orthosiphon aristatus as a model study

Contact Info

Product

Resources

About