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The influence of different water types and brewing durations on the colloidal properties of green tea infusion
Author(s) -
Li Jinglei,
Joung Hee Joung,
Lee Il Woo,
Chen Xiguang,
Park Hyun Jin
Publication year - 2015
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/ijfs.12916
Subject(s) - distilled water , green tea , dispersity , zeta potential , colloid , particle size , dynamic light scattering , chemistry , transmission electron microscopy , chromatography , materials science , food science , nanotechnology , nanoparticle , organic chemistry
Summary Green tea infusions were prepared with three different water types: distilled water, commercial mineral water and C a C l 2 added distilled water (at 20 mg L −1 ). The impact of different water type on the colloidal particle parameters, namely size, polydispersity index ( PDI ) and zeta potential, was examined within 24 h. Our results indicate that distilled water green tea infusion ( DWT ) brewed at 80 °C for 5 min contained the smallest particles (242.17 ± 11.78 nm) as examined by dynamic light scattering ( DLS ). Moreover, DWT showed smaller size increase during the 24 h storage than that of mineral water tea and C a C l 2 added water tea infusion. The morphology characteristics of green tea infusion particles were visualised by transmission electron microscope ( TEM ) which revealed that green tea infusion particles had heteromorphic shapes. Our results suggest that mineral composition of water impacts the colloidal size and stability of green tea infusion. Additionally, DLS and TEM could be useful tools to provide colloidal information which is important to understand quality characteristics of green tea infusion during processing and storage.