Naslov
HPLC Analysis of Bioactive Compounds in Unfermented Products of Camellia Sinensis

Autori
Belščak, Ana ; Horžić, Dunja ; Komes, Draženka ; Kovačević Ganić, Karin

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Book II of Proceedings of the Euro Food Chem XV - Food for the Future - The Contribution of Chemistry to Improvement of Food Quality / Sø rensen, H. i sur. - Kopenhagen : CRC Press ; Taylor & Francis, 2009, 60-63

ISBN
978-87-993033-5-9

Skup
Euro Food Chem XV - Food for the Future

Mjesto i datum
Kopenhagen, Danska, 05.07.2009. - 08.07.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Antioxidant capacity; Camellia sinensis; HPLC; polyphenols; methylxanthines

Sažetak
Unfermented types of true tea (Camellia Sinensis) present a very popular beverage with potential health benefits. In this study, three types of unfermented tea were investigated – Pai mu tan superior (white tea) ; Jin zhen (yellow tea) and Matcha (green tea). The objective was to determine the effects of temperature and duration on the content of extracted phenolic compounds and methylxanthines, as well as the antioxidant capacity of obtained extracts. Individual polyphenols and methylxanthines were determined by means of high performance liquid chromatography (HPLC). Dominant group of polyphenols in all investigated teas were flavan-3-ols, with epigallocatechin gallate being the most abundant, ranging from 68.29 to 345.55 mg/L. The most abundant methylxanthine was caffeine (81.60-368.41 mg/L). Content of these compounds increased with increased temperature and time of extraction. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2’ -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assays were used to assess the antioxidant capacity of tea extracts. Both methods revealed high antioxidant capacity of obtained tea extracts, which ranged from 2.56 to 12.54 mmol/L Trolox (DPPH method), and 0.49 to 19.60 mmol/L Trolox (ABTS method). Presented results reveal high nutritional value of unfermented tea types, and their substantial contribution to the modern diet. Of all investigated teas, Matcha (green tea) was the richest source of polyphenols and Jin zhen (yellow tea) had the highest content of methylxanthines. Pai mu tan superior (white tea) and Jin zhen (yellow tea) exhibited similar antioxidant capacity which was considerably lower than that of green tea.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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