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Çaydaki Kafein Miktarına Farklı Demleme ve Analiz Şartlarının Etkisi

Yıl 2023, Cilt: 10 Sayı: 2, 363 - 372, 30.11.2023
https://doi.org/10.35193/bseufbd.1229430

Öz

Kafein, önemli bir tarımsal ürün olan çayın en önemli bileşenidir. Kafein yaygın kullanımı nedeniyle büyük ticari değer taşımaktadır. Sinir sistemi üzerine uyarıcı etkiye sahip olan kafein, aşırı tüketildiğinde istenmeyen etkilere neden olabilmektedir. Türkiye, Dünya çay üretiminde altıncı sıradadır fakat yıllık kişi başına çay tüketiminde birinci sırada yer almaktadır. Kafeinin ekonomik önemi ve ülkemizdeki çay tüketiminin fazla olması nedeniyle çayın kafein içeriğinin kesin olarak bilinmesi önem taşımaktadır. Bu çalışmada çayın kafein içeriği farklı demleme ve analiz şartları uygulanarak, UV-Vis spektrofotometre cihazı ile belirlenmiştir. Çay demleri hazırlanırken demlikte çay demleme yöntemi dikkate alınarak durgun şartlarda çalışılmış, üç farklı sıcaklıkta farklı demleme süresi, çay/su ve dem/kloroform oranı için yüzde kafein içerikleri bulunmuştur. Bu çalışmaya göre, çayda analiz edilen kafein değerleri demleme sıcaklığına çok bağlıdır. Düşük sıcaklıklarda kafeinin deme çekilmesi için uzun süre gerekmekte, yüksek sıcaklıkta çay/su oranı artışı kafein değerini etkilemektedir. Kloroform üç farklı sıcaklık için yüksek hacimli demlerden bile kafeini ekstrakte edebilmektedir. Düşük LOD (0.338 mg/L) ve LOQ (1.025 mg/L) değerleri ile bu yöntem kafeinsiz kahve ya da çay ve bitki çayları için de uygundur.

Kaynakça

  • Komes, D., Horžić D., Belščak A., Ganič K. K. & Baljak, A. (2009). Determination of caffeine content in tea and maté tea by using different methods, Czech Journal of Food Sciences, 27, 213-216.
  • Gerald, I., Arthur, D. E., & Adedayo, A. (2014). Determination of caffeine in beverages: A review. American Journal of Engineering Research (AJER), 3(8), 124-137
  • Hancı, M., Bakırcı, S., Bayram S., Karahan S., & Kaya, E. (2013). Türk kahvesi ve Türkiye’de satılan bazı içeceklerdeki kafein miktarları. Düzce Tıp Dergisi, 15(3), 34-38.
  • dePaula J., & Farah A. (2019). Caffeine consumption through coffee: Content in the beverage, metabolism, health benefits and risks. Beverages, 5(37), 1-50.
  • Lundsberg, L.S. (1998). Caffeine consumption, In: Spiller, G.A. (Ed). Caffeine. 1st ed., Boca Raton, FL: CRC Press; 199–224.
  • Weldegebreal, B., Redi-Abshiro, M. & Chandravanshi, B. S. (2017), Development of new analytical methods for the determination of caffeine content in aqueous solution of green coffee beans. Chemistry Central Journal, 11,126.
  • Tfouni, S. A. V., Camara, M. M., Kamikata, K., Gomes, F. M. L. & Furlani, R. P. Z. (2018). Caffeine in teas: levels, transference to infusion and estimated intake. Food Science and Technology, 38(4), 661-666.
  • Najafi, N. M., Hamid, A. S. & Afshin, R. K. (2003). Determination of caffeine in black tea leaves by Fourier transform infrared spectrometry using multiple linear regression. Microchemical Journal, 75(3), 151–158.
  • Atalay, D., & Erge, H. S. (2017). Determination of some physical and chemical properties of white, green and black teas (Camellia Sinensis). Gıda/the Journal of Food, 42(5), 494-504.
  • Wong, C. C., Cheng, K. W., Chao, J., Peng, X., Zheng, Z., Wu, J., Chen, F. & Wang, F. (2009). Analytical methods for bioactive compounds in teas. In: Ho, C.T., Lin, J.K., Shahidi, F. (Eds).Tea and Tea Products: Chemistry and Health–Promoting Properties. Boca Raton, FL: CRC Press, 77–110.
  • Güneş, S. (2012). Türk çay kültürü ve ürünleri. Milli Folklor, 24(93), 234-251.
  • Üstün, Ç., & Demirci, N. (2013). Çay bitkisinin (Camellia Sinensis L.) tarihsel gelişimi ve tıbbi açıdan değerlendirilmesi. Lokman Hekim Journal, 3(3), 5–12.
  • Maughan, R.J, & Griffin, J. (2003). Caffeine ingestion and fluid balance: a review. J Hum Nutr Diet, 16(6), 411–20.
  • Sharif, R., Ahmad, S.W., Ramzan, N. & Malik, S.R. (2013). Effect of infusion time and temperature on decaffeination of tea using liquid–liquid extraction technique. J Food Process Eng, 37(1), 46-52.
  • Musilová, A. & Kubíčková, A. (2018). Effect of brewing conditions on caffeine content in tea infusions simulating home-made cup of tea. Monash Chem, 149, 1561–1566.
  • Suteerapataranon, S., Butsoongnern, J., Punturat, P., Jorpalit, W. & Thanomsilp, C. (2009). Caffeine in Chiang Rai tea infusions: Effects of tea variety, type, leaf form, and infusion conditions. Food Chemistry, 114, 1335–1338.
  • Jun, X. (2009). Caffeine extraction from green tea leaves assisted by high pressure processing. Journal of Food Engineering, 94(1), 105-109.
  • Astill, C., Birch, M.R, Dacombe, C., Humphrey, P.G. & Martin, P.T. (2001), Factors affecting the caffeine and polyphenol contents of black and green tea infusions. J. Agric. Food Chem. 49, 5340–5347.
  • Perva-Uzunalic´, A., Škerget, M., Knez, Zˇ., Weinreich, B., Otto, F. & Grüner, S. (2006). Extraction of active ingredients from green tea (Camellia sinensis): Extraction efficiency of major catechins and caffeine. Food Chemistry, 96(4), 597–605.
  • Rehman, R. & Ashraf, S. (2017). Analysis of caffeine contents in commercial beverages and tea samples of Pakistan using UV/Visible spectrometry. Bulgarian Chemical Communications, 49(4), 823 – 828.
  • Belay, A., Ture, K., Redi, M. & Asfaw, A. (2008). Measurement of caffeine in coffee beans with UV/VIS spectrometer, Food Chemistry, 108, 310–315.
  • Paradkar, M. M. & Irudayaraj, J. (2002). Rapid determination of caffeine content in soft drinks using FTIR– ATR spectroscopy. Food Chemistry, 78, 261–266.
  • Edwards, H. G. M., Farwell, D. W., de Oliveira, L. F. C., Alia, J-M., Hyaric, M. L., & de Ameida, M. V. (2005). FT- Raman spectroscopic studies of guarana and some extracts. Analytica Chimica Acta, 532(2), 177-186.
  • Amini, T. & Hashemi P. (2018). Preconcentration and GC–MS determination of caffeine in tea and coffee using homogeneous liquid–liquid microextraction based on solvents volume ratio alteration, Journal of Chromatography B, 1092, 252-257.
  • Bhawani, S. A., Fong, S. S., & Ibrahim, M. N. M. (2015). Spectrophotometric analysis of caffeine. International Journal of Analytical Chemistry, 1-7.
  • Atomssa, T. & Gholap, A.V. (2011). Characterization of caffeine and determination of caffeine in tea leaves using uv-visible spectrometer. African Journal of Pure and Applied Chemistry, 5(1), 1-8.
  • Wondimkun, Z. T., Jebessa, A. G., Molloro, L. H. & Haile, T. (2016). The determination of caffeine level of Wolaita zone, Ethiopia coffee using UV-visible spectrophotometer. American Journal of Applied Chemistry, 4(2), 59–63.
  • Özçomak, M.S. & Çebi, K. (2017). İstatiksel güç analizi: Atatürk üniversitesi iktisadi ve idari bilimler dergisi üzerine bir uygulama. Atatürk Üniversitesi İktisadi ve İdari Bilimler Dergisi, 31(2), 413-431.
  • Özsoy, S. & Özsoy G. (2013). Eğitim Araştırmalarında Etki Büyüklüğü Raporlanması. Elementary Education Online, 12(2), 334‐346.
  • Norouzian, R. & Plonsky, L. (2018). Eta-and partial eta-squared in L2 research: A cautionary review and guide to more appropriate usage. Second Language Research, 34(2), 257–271.
  • Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum Associates, 567.
  • Correll, J., Mellinger, C., McClelland, G. H. & Judd, C. M. (2020). Avoid Cohen's “small,” “medium,” and “large” for power analysis. Trends in Cognitive Science, 24(3), 200–207.
  • Fritz, C.O., Morris, P.E. & Richler, J.J. (2012). Effect size estimates: Current use, calculations and interpretation. Journal of Experimental Psychology: General, 141, 2-18.
  • Shrivastava A & Gupta V.B. Methods for the determination of limit of detection and limit of quantitation of the analytical methods. (2011). Chronicles of Young Scientists, 2 (1), 21-25.
  • Miller, J. C. & Miller, J. N. (2010). Statistics and Chemometrics for Analytical Chemistry.(6th ed.), New York: Pearson Education Limited.
  • ICH Q2 (R1): Validation of Analytical Procedures: Text and Methodology. European Medicine Agency, https://www.ema.europa.eu/en/ich-q2r2-validation-analytical-procedures-scientific-guideline. 2023.
  • Dobrinas, S., Soceanu, A., Popescu, V., Stanciu, G. & Smalberger, S. (2013). Optimization of a UV-VIS spectrometric method for caffeine analysis in tea, coffee and other beverages. Scientific Study and Research. Chemistry and Chemical Engineering, Biotechnology, Food Industry, 14(2), 71-78.
  • Khalid, A., Ahmad, S., Raza, H., Batool, M., Lodhi, R. K., Ain, Q. T. & Naseer F. (2016). Determination of caffeine in soft and energy drinks available in market by using UV/Visible spectrophotometer. Family Medicine and Medical Science Research, 5(4), 1-5.
  • Sereshti, H. & Samadi, S. Rapid and simple determination of caffeine in teas, coffees and eight beverages. (2014). Food Chemistry, 158, 8–13.
  • Sivrikaya, S., A deep eutectic solvent based liquid phase microextraction for the determination of caffeine in Turkish coffee samples by HPLC-UV. (2020). Food additives & Contaminants: Part A, 37(3), 488–495.
  • Viencz, T., Acre, L. B.,, Rocha, R. B., Alves, E.A., Ramalho, A. R. & Benassi M.T. Caffeine, trigonelline, chlorogenic acids, melanoidins, and diterpenes contents of Coffea canephora coffees produced in the Amazon. (2023). Journal of Food Composition and Analysis (17),105140.
  • Ohnsmann, J., Quintás, G., Garrigues, S & Guardia, M. Determination of caffeine in tea samples by Fourier transform infrared spectrometry (2002). Analytical and Bioanalytical Chemistry, 374, 561–565.
  • Tabachnick, B. G., & Fidell, L. S. (2013). Using multivariate statistics (6th ed.). New Jersey, Pearson Education, 1072.
  • Leech, N.L., Barrett, K.C. & Morgan, G.A. (2005) SPSS for Intermediate Statistics: Use and Interpretation. 2nd Edition, Mahwah, Lawrence Erlbaum Associates, 240.
  • Nyamiyen, Y., Adjé, F., & Niamké, F., Koffi, E., Chatigre, O., Adima, A. & Biego, H.G. (2015). Effect of Solvents and Solid- Liquid Ratio on Caffeine Extraction from Côte d’Ivoire Kola Nuts. International Journal of Science and Research (IJSR), 4(1), 218–222.
  • Ramalho, S. A., Nigam, N., Oliveira, G. B., de Oliveira, P. A., Silva, T. O. M., dos Santos, A. G. P. & Narain, N. (2013). Effect of infusion time on phenolic compounds and caffeine content in black tea. Food Research International, 51, 155-161.
  • Polat, A., Kalcıoğlu, Z. & Müezzinoğlu, N. (2022). Effect of infusion time on black tea quality, mineral content and sensory properties prepared using traditional Turkish infusion method. International Journal of Gastronomy and Food Science, 29, 100559.
  • Özdemir, F., Nadeem, H. Ş., Akdoğan, A., Dinçer, C. & Topuz, A. (2018). Effect of altitude, shooting period, and tea grade on the catechins, caffeine, theaflavin, and thearubigin of Turkish black tea. Turkish Journal of Agriculture and Forestry, 42(5), 334-340.
  • Özdemir F, Gökalp H.Y. & Nas, S. (1993). Effects of shooting period, times within shooting periods and processing systems on the extract, caffeine and crude fiber contents of black tea. Zeitschrift fur Lebensmittel Untersuchung und- Forschung, 197, 358-362.
  • Erol, N.T., Sarı, F., & Velioglu, Y.S. (2009). Polyphenols, alkaloids and antioxidant activity of different grades Turkish black tea. Gida, 35, 161–168.

Effect of Different Brewing and Analysis Conditions on Caffeine Content in Tea

Yıl 2023, Cilt: 10 Sayı: 2, 363 - 372, 30.11.2023
https://doi.org/10.35193/bseufbd.1229430

Öz

Caffeine is the main component of tea that is important as an agricultural product. Caffeine has a great commercial value because of its different industrial applications. It has a stimulating effect on the nervous system and can cause undesirable effects when consumed excessively. Turkey is a significant producer of tea, ranking sixth in the world but has one of the world’s highest per capita consumption levels. Due to the economic importance of caffeine and the health effects caused by high consumption level of tea, it is important to know the caffeine content of tea precisely. In this study, the caffeine content of the tea was determined by applying different brewing and analysis conditions with UV-Vis spectrophotometer. While preparing tea infusions, stagnant conditions were used by considering the brewing tea in the teapot and the percentage of caffeine contents were obtained by changing the brewing time, tea/water and infusion/chloroform ratio for three different temperatures. According to the results, the measured caffeine are highly dependent on brewing temperature. Brewing requires a long time at low temperatures and the increase in tea/water ratio at high temperature affects the caffeine percentage. Chloroform is capable of extracting the caffeine from tea infusions even at high volume of infusions and high temperature. Since it has low LOD (0.338 mg/L) and LOQ (1.025 mg/L) values, this method is also suitable for decaffeinated coffee or tea and herbal teas.

Kaynakça

  • Komes, D., Horžić D., Belščak A., Ganič K. K. & Baljak, A. (2009). Determination of caffeine content in tea and maté tea by using different methods, Czech Journal of Food Sciences, 27, 213-216.
  • Gerald, I., Arthur, D. E., & Adedayo, A. (2014). Determination of caffeine in beverages: A review. American Journal of Engineering Research (AJER), 3(8), 124-137
  • Hancı, M., Bakırcı, S., Bayram S., Karahan S., & Kaya, E. (2013). Türk kahvesi ve Türkiye’de satılan bazı içeceklerdeki kafein miktarları. Düzce Tıp Dergisi, 15(3), 34-38.
  • dePaula J., & Farah A. (2019). Caffeine consumption through coffee: Content in the beverage, metabolism, health benefits and risks. Beverages, 5(37), 1-50.
  • Lundsberg, L.S. (1998). Caffeine consumption, In: Spiller, G.A. (Ed). Caffeine. 1st ed., Boca Raton, FL: CRC Press; 199–224.
  • Weldegebreal, B., Redi-Abshiro, M. & Chandravanshi, B. S. (2017), Development of new analytical methods for the determination of caffeine content in aqueous solution of green coffee beans. Chemistry Central Journal, 11,126.
  • Tfouni, S. A. V., Camara, M. M., Kamikata, K., Gomes, F. M. L. & Furlani, R. P. Z. (2018). Caffeine in teas: levels, transference to infusion and estimated intake. Food Science and Technology, 38(4), 661-666.
  • Najafi, N. M., Hamid, A. S. & Afshin, R. K. (2003). Determination of caffeine in black tea leaves by Fourier transform infrared spectrometry using multiple linear regression. Microchemical Journal, 75(3), 151–158.
  • Atalay, D., & Erge, H. S. (2017). Determination of some physical and chemical properties of white, green and black teas (Camellia Sinensis). Gıda/the Journal of Food, 42(5), 494-504.
  • Wong, C. C., Cheng, K. W., Chao, J., Peng, X., Zheng, Z., Wu, J., Chen, F. & Wang, F. (2009). Analytical methods for bioactive compounds in teas. In: Ho, C.T., Lin, J.K., Shahidi, F. (Eds).Tea and Tea Products: Chemistry and Health–Promoting Properties. Boca Raton, FL: CRC Press, 77–110.
  • Güneş, S. (2012). Türk çay kültürü ve ürünleri. Milli Folklor, 24(93), 234-251.
  • Üstün, Ç., & Demirci, N. (2013). Çay bitkisinin (Camellia Sinensis L.) tarihsel gelişimi ve tıbbi açıdan değerlendirilmesi. Lokman Hekim Journal, 3(3), 5–12.
  • Maughan, R.J, & Griffin, J. (2003). Caffeine ingestion and fluid balance: a review. J Hum Nutr Diet, 16(6), 411–20.
  • Sharif, R., Ahmad, S.W., Ramzan, N. & Malik, S.R. (2013). Effect of infusion time and temperature on decaffeination of tea using liquid–liquid extraction technique. J Food Process Eng, 37(1), 46-52.
  • Musilová, A. & Kubíčková, A. (2018). Effect of brewing conditions on caffeine content in tea infusions simulating home-made cup of tea. Monash Chem, 149, 1561–1566.
  • Suteerapataranon, S., Butsoongnern, J., Punturat, P., Jorpalit, W. & Thanomsilp, C. (2009). Caffeine in Chiang Rai tea infusions: Effects of tea variety, type, leaf form, and infusion conditions. Food Chemistry, 114, 1335–1338.
  • Jun, X. (2009). Caffeine extraction from green tea leaves assisted by high pressure processing. Journal of Food Engineering, 94(1), 105-109.
  • Astill, C., Birch, M.R, Dacombe, C., Humphrey, P.G. & Martin, P.T. (2001), Factors affecting the caffeine and polyphenol contents of black and green tea infusions. J. Agric. Food Chem. 49, 5340–5347.
  • Perva-Uzunalic´, A., Škerget, M., Knez, Zˇ., Weinreich, B., Otto, F. & Grüner, S. (2006). Extraction of active ingredients from green tea (Camellia sinensis): Extraction efficiency of major catechins and caffeine. Food Chemistry, 96(4), 597–605.
  • Rehman, R. & Ashraf, S. (2017). Analysis of caffeine contents in commercial beverages and tea samples of Pakistan using UV/Visible spectrometry. Bulgarian Chemical Communications, 49(4), 823 – 828.
  • Belay, A., Ture, K., Redi, M. & Asfaw, A. (2008). Measurement of caffeine in coffee beans with UV/VIS spectrometer, Food Chemistry, 108, 310–315.
  • Paradkar, M. M. & Irudayaraj, J. (2002). Rapid determination of caffeine content in soft drinks using FTIR– ATR spectroscopy. Food Chemistry, 78, 261–266.
  • Edwards, H. G. M., Farwell, D. W., de Oliveira, L. F. C., Alia, J-M., Hyaric, M. L., & de Ameida, M. V. (2005). FT- Raman spectroscopic studies of guarana and some extracts. Analytica Chimica Acta, 532(2), 177-186.
  • Amini, T. & Hashemi P. (2018). Preconcentration and GC–MS determination of caffeine in tea and coffee using homogeneous liquid–liquid microextraction based on solvents volume ratio alteration, Journal of Chromatography B, 1092, 252-257.
  • Bhawani, S. A., Fong, S. S., & Ibrahim, M. N. M. (2015). Spectrophotometric analysis of caffeine. International Journal of Analytical Chemistry, 1-7.
  • Atomssa, T. & Gholap, A.V. (2011). Characterization of caffeine and determination of caffeine in tea leaves using uv-visible spectrometer. African Journal of Pure and Applied Chemistry, 5(1), 1-8.
  • Wondimkun, Z. T., Jebessa, A. G., Molloro, L. H. & Haile, T. (2016). The determination of caffeine level of Wolaita zone, Ethiopia coffee using UV-visible spectrophotometer. American Journal of Applied Chemistry, 4(2), 59–63.
  • Özçomak, M.S. & Çebi, K. (2017). İstatiksel güç analizi: Atatürk üniversitesi iktisadi ve idari bilimler dergisi üzerine bir uygulama. Atatürk Üniversitesi İktisadi ve İdari Bilimler Dergisi, 31(2), 413-431.
  • Özsoy, S. & Özsoy G. (2013). Eğitim Araştırmalarında Etki Büyüklüğü Raporlanması. Elementary Education Online, 12(2), 334‐346.
  • Norouzian, R. & Plonsky, L. (2018). Eta-and partial eta-squared in L2 research: A cautionary review and guide to more appropriate usage. Second Language Research, 34(2), 257–271.
  • Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum Associates, 567.
  • Correll, J., Mellinger, C., McClelland, G. H. & Judd, C. M. (2020). Avoid Cohen's “small,” “medium,” and “large” for power analysis. Trends in Cognitive Science, 24(3), 200–207.
  • Fritz, C.O., Morris, P.E. & Richler, J.J. (2012). Effect size estimates: Current use, calculations and interpretation. Journal of Experimental Psychology: General, 141, 2-18.
  • Shrivastava A & Gupta V.B. Methods for the determination of limit of detection and limit of quantitation of the analytical methods. (2011). Chronicles of Young Scientists, 2 (1), 21-25.
  • Miller, J. C. & Miller, J. N. (2010). Statistics and Chemometrics for Analytical Chemistry.(6th ed.), New York: Pearson Education Limited.
  • ICH Q2 (R1): Validation of Analytical Procedures: Text and Methodology. European Medicine Agency, https://www.ema.europa.eu/en/ich-q2r2-validation-analytical-procedures-scientific-guideline. 2023.
  • Dobrinas, S., Soceanu, A., Popescu, V., Stanciu, G. & Smalberger, S. (2013). Optimization of a UV-VIS spectrometric method for caffeine analysis in tea, coffee and other beverages. Scientific Study and Research. Chemistry and Chemical Engineering, Biotechnology, Food Industry, 14(2), 71-78.
  • Khalid, A., Ahmad, S., Raza, H., Batool, M., Lodhi, R. K., Ain, Q. T. & Naseer F. (2016). Determination of caffeine in soft and energy drinks available in market by using UV/Visible spectrophotometer. Family Medicine and Medical Science Research, 5(4), 1-5.
  • Sereshti, H. & Samadi, S. Rapid and simple determination of caffeine in teas, coffees and eight beverages. (2014). Food Chemistry, 158, 8–13.
  • Sivrikaya, S., A deep eutectic solvent based liquid phase microextraction for the determination of caffeine in Turkish coffee samples by HPLC-UV. (2020). Food additives & Contaminants: Part A, 37(3), 488–495.
  • Viencz, T., Acre, L. B.,, Rocha, R. B., Alves, E.A., Ramalho, A. R. & Benassi M.T. Caffeine, trigonelline, chlorogenic acids, melanoidins, and diterpenes contents of Coffea canephora coffees produced in the Amazon. (2023). Journal of Food Composition and Analysis (17),105140.
  • Ohnsmann, J., Quintás, G., Garrigues, S & Guardia, M. Determination of caffeine in tea samples by Fourier transform infrared spectrometry (2002). Analytical and Bioanalytical Chemistry, 374, 561–565.
  • Tabachnick, B. G., & Fidell, L. S. (2013). Using multivariate statistics (6th ed.). New Jersey, Pearson Education, 1072.
  • Leech, N.L., Barrett, K.C. & Morgan, G.A. (2005) SPSS for Intermediate Statistics: Use and Interpretation. 2nd Edition, Mahwah, Lawrence Erlbaum Associates, 240.
  • Nyamiyen, Y., Adjé, F., & Niamké, F., Koffi, E., Chatigre, O., Adima, A. & Biego, H.G. (2015). Effect of Solvents and Solid- Liquid Ratio on Caffeine Extraction from Côte d’Ivoire Kola Nuts. International Journal of Science and Research (IJSR), 4(1), 218–222.
  • Ramalho, S. A., Nigam, N., Oliveira, G. B., de Oliveira, P. A., Silva, T. O. M., dos Santos, A. G. P. & Narain, N. (2013). Effect of infusion time on phenolic compounds and caffeine content in black tea. Food Research International, 51, 155-161.
  • Polat, A., Kalcıoğlu, Z. & Müezzinoğlu, N. (2022). Effect of infusion time on black tea quality, mineral content and sensory properties prepared using traditional Turkish infusion method. International Journal of Gastronomy and Food Science, 29, 100559.
  • Özdemir, F., Nadeem, H. Ş., Akdoğan, A., Dinçer, C. & Topuz, A. (2018). Effect of altitude, shooting period, and tea grade on the catechins, caffeine, theaflavin, and thearubigin of Turkish black tea. Turkish Journal of Agriculture and Forestry, 42(5), 334-340.
  • Özdemir F, Gökalp H.Y. & Nas, S. (1993). Effects of shooting period, times within shooting periods and processing systems on the extract, caffeine and crude fiber contents of black tea. Zeitschrift fur Lebensmittel Untersuchung und- Forschung, 197, 358-362.
  • Erol, N.T., Sarı, F., & Velioglu, Y.S. (2009). Polyphenols, alkaloids and antioxidant activity of different grades Turkish black tea. Gida, 35, 161–168.
Toplam 50 adet kaynakça vardır.

Ayrıntılar

Birincil Dil Türkçe
Konular Mühendislik, Gıda Mühendisliği
Bölüm Makaleler
Yazarlar

Cemile Yerlikaya 0000-0003-3023-7028

Yayımlanma Tarihi 30 Kasım 2023
Gönderilme Tarihi 5 Ocak 2023
Kabul Tarihi 13 Nisan 2023
Yayımlandığı Sayı Yıl 2023 Cilt: 10 Sayı: 2

Kaynak Göster

APA Yerlikaya, C. (2023). Çaydaki Kafein Miktarına Farklı Demleme ve Analiz Şartlarının Etkisi. Bilecik Şeyh Edebali Üniversitesi Fen Bilimleri Dergisi, 10(2), 363-372. https://doi.org/10.35193/bseufbd.1229430