To determine differences in quality parameters between different types of tea elaborated in Argentina, water extract, crude fibre, caffeine, total polyphenol content, antioxidant activity, sorption isotherms and colour parameters (L, a, b) were determined. Fifty-one industrial samples of commercially available teas including green tea, semifermented tea, black tea and black tea sub-product (BTSP) were used for this study.Water extract contents were significantly higher in black tea and green tea (40.3% and 40.7% w/w, respectively), while semifermented tea and BTSP showed higher levels of crude fibre (22.3% and 20.4% w/w, respectively). Caffeine contents of black teas (2.7% w/w) were significantly higher than in the other types of tea. Green teas revealed the highest concentrations of phenolic compounds and the major antioxidant activities (14.9 g GAE/100g dm and 30.0 g AAE/100g dm, respectively). The results also highlighted significant differences (p<0.05) in colour values between the different types of tea.
Anesini C, Ferraro G, Filip R. Total polyphenol content and antioxidant capacity of commercially available tea (Camel-IJFS October. Journal of Agricultural and Food Chemistry. 2008. p. 9225–9.
2.
Astill C, Birch M, Dacombe C, Humphrey P, Martin P. Factors affecting the caffeine and polyphenol contents of black and green tea infusions. Journal of Agricultural and Food Chemistry. 2001. p. 5340–7.
3.
FAO Statistics Division. 2011.
4.
Fernández P, Martín M, González A, Pablos F. HPLC determination of catechins and caffeine in tea. Differentiation of green, black and instant teas. Analyst. 2000. p. 421–5.
5.
Ghodake H, Goswami T, Chakraverty A. Moisture sorption isotherms, heat of sorption and vaporization of withered leaves, black and green tea. Journal of Food Engineering. 2007. p. 827–35.
6.
Gramza A, Korczak J. Tea constituents (Camellia sinensis L.) as antioxidants in lipid systems. Trends in Food Science & Technology. 2005. p. 351–8.
7.
Greenspan L. Humidity Fixed-Points of Binary Saturated Aqueous-Solutions. Journal of Research of The National Bureau of Standards Section A-Physics And Chemistry. 1977. p. 89–96.
8.
Hartwig V, Brumovsky L, Fretes R, Sánchez Boado L. A novel procedure to measure the antioxidant capacity of Yerba maté extracts. Ciência e Tecnologia de Alimentos. 2012. p. 126–33.
9.
Tea and instant tea in solid form -Determination of caffeine content -Method using High Performance Liquid Chromatography. 2002.
10.
ISO 11287. 2011.
11.
Determination of substances characteristic of green and black tea -Part 1: Content of total polyphenols in tea -Colorimetric method using Folin-Ciocalteu reagent. 2004.
12.
Tea -Determination of crude fibre content. 1999.
13.
Tea -Determination of loss in mass at 103 • C. 1981.
14.
Tea -Determination of water extract. 1994.
15.
Jayasekera S, Molan A, Garg M, Moughan P. Variation in antioxidant potential and total polyphenol content of fresh and fully-fermented Sri Lankan tea. Food Chemistry. 2011. p. 536–41.
16.
Karori S, Wachira F, Wanyoko J, Ngure R. Antioxidant capacity of different types of tea products. African Journal of Biotechnology. 2007. p. 2287–96.
17.
Kerio L, Wachira F, Wanyoko J, Rotich M. Characterization of anthocyanins in Kenyan teas: Extraction and identification. Food Chemistry. 2012. p. 31.
18.
Khokhar S, Magnusdottir S. Total phenol, catechin, and caffeine contents of teas commonly consumed in the United Kingdom. Journal of Agricultural and Food Chemistry. 2002. p. 565–70.
19.
Kim Y, Goodner K, Park JD, Choi J, Talcott S. Changes in antioxidant phytochemicals and volatile composition of Camellia sinensis by oxidation during tea fermentation. Food Chemistry. 2011. p. 1331–42.
20.
Lin J, Lin C, Liang Y, Lin-Shiau S, Juan I. Survey of catechins, gallic acid, and methylxanthines in green, oolong, pu-erh, and black teas. Journal of Agricultural and Food Chemistry. 1998. p. 3635–42.
21.
Lin Y, Tsai Y, Tsay J, Lin J. Factors affecting the levels of tea polyphenols and caffeine in tea leaves. Journal of Agricultural and Food Chemistry. 2003. p. 1864–73.
22.
Luczaj W, Skrzydlewska E. Antioxidative properties of black tea. Preventive Medicine. 2005. p. 910–8.
23.
Muthumani T, Kumar R. Influence of fermentation time on the development of compounds responsible for quality in black tea. Food Chemistry. 2007. p. 98–102.
24.
Parra P. Secretaría de Agricultura, Ganadería, Pesca y Alimentos. Ministerio de Economía y Producción; 2007.
25.
Prat Kricun S, De Bernardi L. Secretaría de Agricultura, Ganadería, Pesca y Alimentos. Food Chemistry. 2002. p. 159–65.
26.
Saito S, Gosmann G, Saffi J, Presser M, Richter M, Bergold A. Characterization of the constituents and antioxidant activity of Brazilian green tea (Camellia sinensis var. assamica IAC-259 Cultivar). extracts. Journal of Agricultural and Food Chemistry. 2007. p. 9409–14.
27.
Schmalko M, Alzamora S. Color, chlorophyll, caffeine, and water content variation during yerba mate processing. Drying Technology. 2001. p. 599–610.
28.
Smiechowska M, Dmowski P. Crude fibre as a parameter in the quality evaluation of tea. Food Chemistry. 2006. p. 366–8.
29.
Von Staszewski M, Pilosof A, Jagus R. Antioxidant and antimicrobial performance of different Argentinean green tea varieties as affected by whey proteins. Food Chemistry. 2011. p. 186–92.
30.
Yao L, Liu X, Jiang Y, Caffin N, Arcy D, Singanusong B, et al. Compositional analysis of teas from Australian supermarkets. Food Chemistry. 2006. p. 115–22.
31.
Yao L, Caffin N, Arcy D, Jiang B, Shi Y, Singanusong J, et al. Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis). Journal of Agricultural and Food Chemistry. 2005. p. 6477–83.
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