Determination of caffeine in tea samples by Fourier transform infrared spectrometry

Ohnsmann, Janina; Quintás, Guillermo; Garrigues, Salvador; Guárdia, Miguel de la

doi:10.1007/s00216-002-1503-8

Cited by 33 publications

(18 citation statements)

References 16 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Caffeine has been determined in tea by different analytical techniques such as ultaviolet‐visible spectrophotometry, amperometry, high‐performance liquid chromatography, ion chromatography, capillary electrophoresis and high‐performance thin layer chromatography, but all of these techniques are time consuming and the effect of interferences are high. In this work, we used Fourier transform infrared (FTIR) for determination of caffeine in tea waste extracts with high precision, accuracy, less contamination and low chloroform consumption (Ohnsmann et al . 2002).…”

Section: Methodsmentioning

confidence: 99%

Isolation of Caffeine From Tea Waste Using Subcritical Water Extraction

Shalmashi¹,

Abedi²,

Golmohammad³

et al. 2010

J Food Process Engineering

View full text Add to dashboard Cite

The aim of this study was to investigate the isolation of caffeine from tea waste using subcritical water extraction (SCWE) method. The effect of various operating conditions such as water temperature (100,125,150, 175 and 200C), water flow rate (1, 2 and 4 g/min), mean particle size (0.25, 0.5, 1 and 2 mm) and pressure (20, 30 and 40 bar) on extraction yield and rate were determined. SCWE at 175C, water flow rate of 4 g/min and mean particle size of 0.5 mm was found to be able to recover 0.77% (w/w) of caffeine present in the tea waste within 1.5 h of extraction. In comparison with the SCWE, conventional hot water extraction showed 0.46% (w/w) extraction yield. It was found also that pressure had no effect on extraction yield and rate. A sustainable and environmentally friendly procedure has been used for the Fourier transform infrared determination of caffeine in tea waste extracted samples. PRACTICAL APPLICATIONS Subcritical water extraction (SCWE), as a green solvent, can be used in many different fields of applications. It can be used to extract antioxidant compounds from rosemary plants as well as to extract whitening agents and azo dyes in samples. Additionally, soil can be remediated through SCWE of dioxins. Recently, subcritical water has become of great interest as an alternative solvent for extraction of natural active compounds. In recent years, extraction of flavors, fragrances and antioxidant components from plant materials, and hydrolysis of carbohydrates, vegetable oils and fatty acids have been widely investigated by many researchers. Using subcritical water as a reaction media are some other interesting fields for practical applications.

show abstract

Section: Methodsmentioning

confidence: 99%

Isolation of Caffeine From Tea Waste Using Subcritical Water Extraction

Shalmashi¹,

Abedi²,

Golmohammad³

et al. 2010

J Food Process Engineering

View full text Add to dashboard Cite

show abstract

“…At present, UV-vis spectrophotometry (Belay, Ture, Redi, & Asfaw, 2008;Ohnsmann, Quintas, Garrigues, & de la Guardia, 2002) and HPLC (Horie, Nesumi, Ujihara, & Kohata, 2002;Zuo, Chen, & Deng, 2002) are most commonly used to determine caffeine in tea. However, these methods demand expensive apparatus, highly skilled technicians, complicated and time-consuming procedures.…”

Section: Introductionmentioning

confidence: 99%

Determination of caffeine content in tea based on poly(safranine T) electroactive film modified electrode

et al. 2011

View full text Add to dashboard Cite

“…Bands around 1699 and 1657 cm -1 may be attributed to the presence of caffeine, 30,71 suggesting that the compound may be the one responsible for the superior layer discrimination. This result agrees with the findings by Delaroza et al, 9 in which sun exposed crude extracts from coffee leaves show higher amount of caffeine, suggesting greater stress suffered by leaves exposed to direct sunlight.…”

Section: Resultsmentioning

confidence: 99%

Irrigation and Light Access Effects on Coffea arabica L. Leaves by FTIR‑Chemometric Analysis

Sanchez¹,

Pauli²,

Scheel³

et al. 2017

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Coffee bean chemical compositions has been extensively studied. However, there is a small amount of research on other parts of the coffee plant, including leaves. Fourier transform infrared (FTIR) spectral profiles of Coffea arabica L. cv. IAPAR 59 leaf extracts from a simplex-centroid design were studied by principal component analysis (PCA) to evaluate the effect of solvent extractor on its metabolites. PCA indicated that the extractor solvents containing ethanol were the most suitable for this study. FTIR spectra in conjunction with orthogonal signal correction and partial least squares-discrimination analysis (OSC-PLS-DA) were used to classify and discriminate the leaves of irrigated and non-irrigated plants by bands related to carbohydrates, amino acids and lipids. Leaves receiving different intensities of solar radiation were also discriminated by bands corresponding to caffeine, carbohydrates and lipids. FTIR spectral profile analyzed with chemometric tools showed to be a useful, powerful and simple procedure to discriminate coffee leaves collected from different microclimate conditions. Keywords:Coffea arabica leaves, simplex-centroid design, FTIR spectroscopy, chemometric analysis, environmental conditions IntroductionThe coffee plant is a woody, perennial, evergreen and dicotyledon species that belongs to the Rubiaceae family. 1,2 Among several species of the genus Coffea, two are considered economically important, i.e. Coffea canephora Pierre (Robusta coffee) and Coffea arabica L. (Arabica coffee). 3 The latter species represents 70% of world coffee production 2 due to finer flavor and aroma, and therefore is more consumed than Robusta. 4 Coffee is one of the most consumed beverages in the world 5,6 and an important raw material of the international trade. 4 Thus, due to its importance, the chemical composition of coffee beans has been extensively studied. However, there is relatively little research carried out on metabolites in other coffee plant parts, including the leaves.7-11 Phenolic compounds found in the coffee leaves 7 have been shown to be potentially beneficial for health, although the influence of consumption of these compounds on the human body requires further research. Other metabolite groups are found in coffee leaves, such as alkaloids, 12 several carbohydrates 13,14 and lipids 9 among others.Plant metabolites are susceptible to environmental changes and their responses can be evaluated by metabolomics analysis. 15 In periods of drought or excessive sun exposure, environmental stress can affect physiological processes in plants owing to their necessity to adapt to the new situation. In excess, these conditions can affect metabolic activities such as photosynthesis and growth rate modifying carbohydrate levels and protein synthesis. [16][17][18][19][20] In coffee plants, these changes may influence the metabolic quantities and consequently, the coffee bean quality. 9,21 Information about chemical modifications in coffee Sanchez et al. 169 Vol. 29, No. 1, 2018 leaves subjecte...

show abstract

Determination of caffeine in tea samples by Fourier transform infrared spectrometry

Cited by 33 publications

References 16 publications

Isolation of Caffeine From Tea Waste Using Subcritical Water Extraction

Isolation of Caffeine From Tea Waste Using Subcritical Water Extraction

Determination of caffeine content in tea based on poly(safranine T) electroactive film modified electrode

Irrigation and Light Access Effects on Coffea arabica L. Leaves by FTIR‑Chemometric Analysis

Contact Info

Product

Resources

About