The composition of polyphenols and methylxanthines in teas and herbal infusions

Horžić, Dunja; Komes, Draženka; Belščak, Ana; Ganić, Karin Kovačević; Iveković, Damir; Karlović, Damir

doi:10.1016/j.foodchem.2008.12.022

Cited by 174 publications

(89 citation statements)

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“…As a result, even though, they can involve same specific SERS band, their SERS intensity may change based on amount of the different chemical bonds. This also confirms the study of Horžić et al (2009) who reported the total identified flavan-3-ol contents of herbal linden tea sample was nearly six-fold higher than chamomile tea samples. In addition, the SERS spectrum of green tea samples had a number of sharp bands compared to the other four tea types.…”

Section: Characterisation Of Silver Colloidssupporting

confidence: 91%

“…The other obvious visible differences between tea types appeared on the intensity of bands related to tea components. These appeared to be present in higher quantities of the total identified flavan-3-ol contents especiially EGCG in non-fermented tea than fermented (black) tea except GC and ECG (most abundant in black tea) (Horžić et al 2009), with the former displaying higher SERS for these bands. Therefore, as shown in Fig.…”

Section: Characterisation Of Silver Colloidsmentioning

confidence: 96%

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Spectroscopic fingerprint of tea varieties by surface enhanced Raman spectroscopy

et al. 2015

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The fingerprinting method is generally performed to determine specific molecules or the behavior of specific molecular bonds in the desired sample content. A novel, robust and simple method based on surface enhanced Raman spectroscopy (SERS) was developed to obtain the full spectrum of tea varieties for detection of the purity of the samples based on the type of processing and cultivation. For this purpose, the fingerprint of seven different varieties of tea samples (herbal tea (rose hip, chamomile, linden, green and sage tea), black tea and earl grey tea) combined with silver colloids was obtained by SERS in the range of 200-2000 cm −1 with an analysis time of 20 s. Each of the thirty-nine tea samples tested showed its own specific SERS spectra. Principal Component Analysis (PCA) was also applied to separate of each tea variety and different models developed for tea samples including three different models for the herbal teas and two different models for black and earl grey tea samples. Herbal tea samples were separated using mean centering, smoothing and median centering pre-processing steps while baselining and derivatisation pre-processing steps were applied to SERS data of black and earl grey tea. The novel spectroscopic fingerprinting technique combined with PCA is an accurate, rapid and simple methodology for the assessment of tea types based on the type of processing and cultivation differences. This method is proposed as an alternative tool in order to determine the characteristics of tea varieties.

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Section: Characterisation Of Silver Colloidssupporting

confidence: 91%

Section: Characterisation Of Silver Colloidsmentioning

confidence: 96%

Spectroscopic fingerprint of tea varieties by surface enhanced Raman spectroscopy

et al. 2015

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“…Herbal tea has been used for health care and diseases prevention for thousands of years in many countries [2]. Moreover, numerous epidemiological studies link herbal tea consumption to a reduction in cardiovascular diseases, cholesterol levels, diabetes, arthritis, osteoporosis and dental carries [3]. Besides giving negligible side effects and mild in action, herbal tea is easy to prepare, richer in resources and cheaper in price [4].…”

Section: Introductionmentioning

confidence: 99%

ANTIOXIDANT ACTIVITY, COLOUR AND MINERAL CONTENT OF HERBAL TEA PREPARED FROM Cosmos caudatus LEAVES AT DIFFERENT MATURITY STAGES

Fatanah¹,

Abdullah²,

Hamid³

2016

MJAS

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In recent years, increasing consumption of herbal tea is a worldwide trend because of their refreshing taste, positive potential health effect, convenience, abundant resources and also cheaper in price. However, different maturity stages of plants being used as raw material could affect the antioxidant activity, colour and mineral content in herbal tea. Thus, this present study was aimed at determining antioxidant activity, colour and mineral content of herbal tea prepared from Cosmos caudatus (C. caudatus) leaves at three different maturity stages namely young, mature and old. All prepared herbal tea were analysed for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, colour and mineral content. The results demonstrated that herbal tea prepared from young leaves had strong (p< 0.05) antioxidant activity compared to mature and old leaves for all assays tested. Pearson's correlation coefficient also revealed that TPC and TFC exhibited a strong positive correlation with reducing power but negatively correlated with DPPH scavenging activity indicating that these compounds are major contributors to the antioxidant activity. In fact, the darker (p< 0.05) colour of C. caudatus herbal tea prepared from young leaves relates to their higher antioxidant activity as compared to mature and old leaves. However, C. caudatus herbal tea prepared from old leaves showed significantly higher in mineral content compared to mature and young leaves. Hence, it can be concluded that, as maturity increased, antioxidant activity and colour in C. caudatus herbal tea decreased and vice-versa for mineral content.Keywords: herbal tea, Cosmos caudatus, maturity, antioxidant activity, colour, mineral content Abstrak Pada masa kini, peningkatan pengambilan teh herba menjadi ikutan terkini di seluruh dunia kerana rasa yang menyegarkan, mempunyai potensi yang positif terhadap kesihatan, sumber yang mudah didapati dan harga yang murah. Walaubagaimanapun, penggunaan sumber bahan mentah daripada tumbuh-tumbuhan pada peringkat kematangan yang berbeza mempengaruhi aktiviti antioksida, warna dan kandungan mineral di dalam teh herba. Oleh itu, kajian ini bertujuan untuk menentukan aktiviti antioksida, warna dan kandungan mineral di dalam teh herba yang dihasilkan daripada daun Cosmos caudatus (C. caudatus) pada tiga peringkat kematangan iaitu daun muda, matang dan tua. Semua sampel teh herba telah dianalisa untuk menentukan jumlah kandungan fenol (TPC), jumlah kandungan flavonoid (TFC), ujian penurunan ferik (FRAP), pemerangkapan radikal bebas 2-2-difenil-1-1pikrilhidrazil (DPPH), warna dan kandungan mineral. Keputusan menunjukkan bahawa, teh herba dihasilkan daripada daun muda mempunyai aktiviti antioksida yang tinggi (p< 0.05) berbanding dengan daun matang dan tua untuk semua asai diuji. ISSN -2506Dian Nashiela et al: ANTIOXIDANT ACTIVITY, COLOUR AND MINERAL CONTENT OF HERBAL TEA PREPARED FROM Cosmos caudatus LEAVES AT DIFFERENT M...

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“…Light green and young leaves are preferably produced for tea production. Leaves of Camellia sinensis reported antimicrobial properties, they contain flavonoids, their analysis and their functions 6 , they inhibits the enzyme ribonuclease A 7 , antioxidant activity 8 , antibacterial activity 9 , tea polyphenols used in the herbal infusions 10 , protection against reactive oxygen species induced degradation of lipids, proteins and 2-deoxyribose by tea catechins 11 , green tea polyphenols having antiatherogenic properties 12 .…”

Section: Introductionmentioning

confidence: 99%

Untitled

2011

IJPSR

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The present study was to evaluate the in vitro cholesterol esterase enzyme inhibitory and in vitro antioxidant activity of the methanol extract of the leaves of Camellia sinensis (L.). Phytochemical screening of the extract shows the presence of flavonoids, phenolics and terpenoids. The extract shows ability to inhibit the enzyme with IC 50 (82.46±0.74µg/ml) whereas that of standard, Orlistat (24.15±0.59µg/ml). Antioxidant and free radical scavenging activity were also assessed by using the methods, IC 50 values for Nitric oxide radical scavenging activity (396.83±0.83µg/ml), whereas for standard curcumin (260.38±0.66µg/ml), hydroxyl radical scavenging activity (47.04±2.26µg/ml) and for quercetin (70.99±1.31µg/ml). Moreover, the extract was found to scavenge the superoxide with 50% inhibition at 308.17±23.25µg/ml and standard ascorbic acid at 225.08±2.44µg/ml, IC 50 for ferrous chelating ability assay (44.12±4.63µg/ml) and of ascorbic acid (47.25±.89µg/ml). Total content of flavonoids present in 1mg of extract was 19.8±0.11 µg quercetin equivalents/mg. Results indicated that the extract shows potential bioactive compounds which might have a beneficial impact on diseases related to cholesterol synthesis and showed potential antioxidant and free radical scavenging activities. INTRODUCTION:Dietary cholesterol comprised of free and esterified cholesterol. In diets rich in meats, significant percent of cholesterol is esterified. Hydrolysis of cholesteryl ester in the lumen is catalyzed by cholesterol esterase (CEase).

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The composition of polyphenols and methylxanthines in teas and herbal infusions

Cited by 174 publications

References 45 publications

Spectroscopic fingerprint of tea varieties by surface enhanced Raman spectroscopy

Spectroscopic fingerprint of tea varieties by surface enhanced Raman spectroscopy

ANTIOXIDANT ACTIVITY, COLOUR AND MINERAL CONTENT OF HERBAL TEA PREPARED FROM Cosmos caudatus LEAVES AT DIFFERENT MATURITY STAGES

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