References
- Ahmed S, Unachukwu U, Stepp JR, Peters CM, Long CL, Kennelly E. 2010. Pu-erh tea tasting in Yunnan, China: correlation of drinkers’ perceptions to phytochemistry. J Ethnopharmacol. 132:176–185.
- Andrade JM, Estévez-Pérez MG. 2014. Statistical comparison of the slopes of two regression lines: a tutorial. Anal Chim Acta. 838:1–12.
- Folin O. 1927. Tyrosine and tryptophan determination in proteins. J Biol Chem. 73:672–649.
- Funk W, Dammann V, Donnevert G. 1995. Quality assurance in analytical chemistry. New York: VHC.
- Gao L, Bian M, Mi R, Hu X, Wu J. 2016. Quality identification and evaluation of Pu-erh teas of different grade levels and various ages through sensory evaluation and instrumental analysis. Int J Food Sci Tech. 51:1338–1348.
- International conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use. In Q2B(R1): Guideline on Validation of analytical Procedure Methodology; ICH Steering Committee: Brussels, Belgium, 2005.
- Jie G, Ling Z, Zhang L, Lv H, He P, Zhao B. 2006. Free radical scavenging effect of Pu-erh tea extracts and their protective effect on oxidative damage in human fibroblast cells. J Agric Food Chem. 54:8058–8064.
- Lee LK, Foo KY. 2013. Recent advances on the beneficial use and health implications of Pu-erh tea. Food Res Int. 53:619–628.
- Liang Y, Zhang L, Lu J. 2005. A study on chemical estimation of Pu-erh tea quality. J Sci Food Agric. 85:381–390.
- Lin JK, Lin C, Liang YC, Lin-Shiau SY, Juan IM. 1998. Survey of catechins, gallic acid, and methylxanthines in green, oolong, Pu-erh, and black teas. J Agric Food Chem. 46:3635–3642.
- Lv H, Zhang Y, Lin Z, Liang Y. 2013. Processing and chemical constituents of Pu-erh tea: a review. Food Res Int. 53:608–618.
- Pérez-Jiménez J, Neveu V, Vos F, Scalbert A. 2010. Identification of the 100 richest dietary sources of polyphenols: an application of the Phenol-Explorer database. Eur J Clin Nutr. 64:S112–S120.
- Prior RL, Wu X, Schaich K. 2005. Standardized methods for the determination of antioxidant capacity and phenolics in foods and dietary supplements. J Agric Food Chem. 53:4290–4302.
- Singleton VL, Rossi JA. 1965. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagent. Am J Enol Viticult. 16:144–158.
- Singleton VL, Orthofer R, Lamuela-Raventos RM. 1999. Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin–Ciocalteu reagent. Method Enzymol. 299:152–178.
- Wang K, Liu F, Liu Z, Huang J, Xu Z, Li Y. 2011. Comparison of catechins and volatile compounds among different types of tea using high performance liquid chromatograph and gas chromatograph mass spectrometer. Int J Food Sci Tech. 46:1406–1412.
- Zhang L, Li N, Ma Z, Tu P. 2011. Comparison of the chemical constituents of aged Pu-erh tea, ripened Pu-erh tea, and other teas using HPLC-DAD-ESI-MSn. J Agric Food Chem. 59:8754–8760.
- Zhang L, Zhang Z, Zhou Y, Ling T, Wan X. 2013. Chinese dark teas: postfermentation, chemistry and biological activities. Food Res Int. 53:600–607.
- Zuo Y, Chen H, Deng Y. 2002. Simultaneous determination of catechins, caffeine and gallic acids in green, oolong, black and Pu-erh teas using HPLC with a photodiode array detector. Talanta. 57:307–316.