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Authentication and Discrimination of Green Tea Samples Using UV-Visible, FTIR and HPLC Techniques Coupled with Chemometrics Analysis

Aboulwafa, MM, Youssef, FS, Gad, HA, Sarker, SD, Nahar, L, Al-Azizi, MM and Ashour, ML Authentication and Discrimination of Green Tea Samples Using UV-Visible, FTIR and HPLC Techniques Coupled with Chemometrics Analysis. Journal of Pharmaceutical and Biomedical Analysis. ISSN 0731-7085 (Accepted)

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Abstract

Green tea is a popular beverage consumed worldwide. Its quality should be controlled adequately as the quality is influenced by several factors in addition to adulterations. This study aimed to develop a simple method for assessing the quality of green tea samples obtained from the South and the East Asian regions. The UV-Visible, FTIR and HPLC data from 38 samples were subjected to multivariate analyses using the unsupervised recognition techniques comprising Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA). The model for their authentication was constructed and validated by applying the supervised recognition techniques as Soft Independent Modeling of Class Analogy (SIMCA) and Partial Least Square Discriminant Analysis (PLS-DA). The percentages of caffeine in the identified samples were determined using a validated HPLC assay in addition to in vitro determination of their antioxidant activity using DPPH radical-scavenging capacity assay. HCA and PCA based on UV data successfully distributed the tested samples into informative clusters. However, that obtained from visible data could only differentiate samples with respect to their powdered condition. On the contrary, PCA from FTIR and HPLC data could hardly discriminate any of the samples. The models constructed using SIMCA and PLS-DA showed a good class separation between the South and the East Asian samples. The percentages of caffeine in the identified samples and the IC50 in DPPH assay are greatly diverse among all the tested samples. Thus, UV spectroscopy and chemometrics have provided a simple and quick tool for the quality control of commercial green tea samples.

Item Type: Article
Uncontrolled Keywords: 0301 Analytical Chemistry, 1115 Pharmacology And Pharmaceutical Sciences
Subjects: T Technology > TX Home economics > TX341 Nutrition. Foods and food supply
Q Science > QD Chemistry
Divisions: Pharmacy & Biomolecular Sciences
Publisher: Elsevier BV
Date Deposited: 22 Nov 2018 11:29
Last Modified: 22 Nov 2018 12:28
URI: http://researchonline.ljmu.ac.uk/id/eprint/9702

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