Vpliv priprave napitkov čaja (Camellia sinensis L.) na vsebnost flavanolov in antioksidativno učinkovitost

Graj, Monika (author), Pogačnik, Lea (mentor), Glavnik, Vesna (co-mentor)

V okviru magistrske naloge smo določali antioksidativno učinkovitost (AOU), vsebnost skupnih fenolnih spojin (SFS) in vsebnost skupnih flavanolov v zelenem, belem, črnem in matcha čaju. Preverjali smo vpliv različnih načinov priprave čajnih infuzij na vsebnost SFS, skupnih flavanolov in AOU. Čajne infuzije smo pripravili tako, da smo zatehtali po 0,4 g posameznega vzorca in slednje prelili s 50 mL destilirane vode. Spremljali smo, kako različna temperatura (70 °C in 100 °C), trajanje ekstrakcije (1, 2, 5, 10, 60 min) in dodatek mleka vplivajo na preiskovane parametre. Ugotovili smo, da daljša ekstrakcija in višja temperatura pozitivno vplivata tako na AOU kot tudi na vsebnosti SFS in skupnih flavanolov. Po drugi strani pa ima dodatek mleka k čajnim infuzijam negativen vpliv na vse tri preučevane parametre. Glede na rezultate vseh analiz pri pripravi čajnih infuzij lahko zaključimo, da ima največjo AOU (5,65 g/L), najvišjo vsebnost SFS (2,12 g/L) in najvišjo vsebnost skupnih flavanolov (3,35 mg/L čaja) čaj matcha.

• Language: Slovenian
• Keywords: antioksidanti, flavanoli, čaj, Camellia sinensis, matcha, antioksidativna učinkovitost, fenolne spojine, analizne metode, Folin-Ciocalteu, DPPH•, TLC
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [M. Graj]
• Year: 2019
• PID: 20.500.12556/RUL-107750
• UDC: 663.95:547.56:66.094.3.097.8
• COBISS.SI-ID: 5053560
• Publication date in RUL: 22.05.2019

Secondary language

• Language: English
• Title: The effect of tea (Camellia sinensis L.) preparation on the flavanol content and antioxidant capacity

Abstract

Within the master's thesis we determined the antioxidant capacity (AOC), content of total phenolic compounds (TP) and content of flavanols in green, white, black and matcha tea. The aim of our study was to examine the influence of different preparation methods of tea infusions on the AOC, content of TP and content of flavanols. The tea infusions were prepared with 0.4 g of each sample and poured with 50 mL of distilled water. We examined the influence of different temperatures (70 °C and 100 °C), the duration of the extraction (1, 2, 5, 10, 60 min) and addition of milk on the selected parameters. We have found that longer duration of the extraction and the higher temperature have positive effect since they increased AOC, TP content and flavanols content of infusions. The addition of milk to tea infusions has a negative impact on all three studied parameters. Based on the overall results of all analyzes in the preparation of tea infusions, we can conclude that matcha tea has the highest AOC (5.65 g/L), the highest TP content (2.12 g/L) and the highest content of total flavanols (3.35 mg/L of tea).

• Keywords: antioxidants, flavanols, tea, Camellia sinensis, matcha, antioxidant capacity, phenolic compounds, analytical methods, Folin-Ciocalteu, DPPH•, TLC