Naslov
Compositional analysis of white teas

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

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

Izvornik
Proceedings of the 2008 Joint Central European Congress, 4th Central European Congress on Food, 6th Croatian Congress of Food Technologists, Biotechnologists and Nutritionists / Ćurić, Duška - Zagreb : Hrvatska gospodarska komora (HGK), 2008, 239-246

ISBN
978-953-6207-87-9

Skup
The 2008 Joint Central European Congress, 4th Central European Congress on Food, 6th Croatian Congress of Food Technologists, Biotechnologists and Nutritionists

Mjesto i datum
Cavtat, Hrvatska, 15.05.2008. - 17.05.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Antioxidants; HPLC; methylxanthines; polyphenols; white tea

Sažetak
All true teas are derived from the buds and leaves of the plant Camellia sinensis, but different processing methods produce different types of tea. The rarest and the least processed of all the true teas, white tea is also the least researched type of tea. Until recently, it was almost unknown outside of Asia, but is becoming increasingly popular because of its health promoting properties. Therefore, it is important to investigate white tea’ s composition and brewing dynamic. The objective of this study was to investigate the composition of three white teas (Pai Mu Tan, Pai Mu Tan superior and Silver Needle) and to determine the effects of temperature, time and multiple extractions on the content of biologically active compounds (phenols and methylxanthynes) and antioxidant capacity in prepared infusions of the most popular white teas on Croatian market. Total phenolic content of tea infusions (80°/3 min) ranged from 600 (Silver Needle) to 1150 (Pai mu tan) mg/L GAE. Content of extracted phenolic compounds increased with increasing water temperature and extraction time. Dominant phenolic compound in all three tea types was epigallocatechin gallate (84, 03-126, 02 mg/L EGCG). Total methylxantine content ranged from 292, 13 (Pai mu tan) to 303, 30 mg/L (Silver Needle). 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method was employed to estimate the antioxidant capacity of tea infusions, which varied from 4, 09 to 5, 81 mmol/L Trolox. White tea is quickly gaining popularity and the results of the present study denote it as a rich source of biologically active compounds.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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