Tea Infusion (tea + infusion)

Distribution by Scientific Domains

Selected Abstracts

Use of different buffers for detection and separation in determination of physio-active components in oolong tea infusion by CZE with amperometric detection

Zhiyong Yang
Abstract With a view of simultaneous determination of physio-active ingredients in oolong tea infusion: sugars, amino acids, epigallocatechin gallate and ascorbic acid, a novel CZE with amperometric detection method was studied. Operated in a wall-jet configuration, 100,mmol/L NaOH was used in detecting cell to lead the electrocatalysis oxidation behaviors of the analytes on a 300,,m diameter copper-disc electrode (working electrode), while in separating capillary, a mild alkaline running buffer consisting in a mixture of 30,mmol/L borate and 40,mmol/L phosphates charged and carried analytes to detecting end. The methodology research was performed for system stability and suitability. Under the optimal CE conditions, analytes could be separated within moderate time period. Good linearity between peak area and concentration existed over three orders of magnitude; lower RSD and LOD were achieved. The oolong tea infusion was assayed and result was satisfactory. [source]

The development of a suitable manufacturing process for ,Benifuuki' green tea beverage with anti-allergic effects

Hiroshi Nagai
Abstract Epigallocatechin-3- O -(3- O -methyl) gallate (EGCG3,Me) has been reported to inhibit type I allergy better than epigallocatechin gallate (EGCG), a major catechin in tea leaves (Camellia sinensis L). We examined the effects of extraction and sterilization on the catechin content and histamine release from mast cells, as a representative reaction of early phase allergy, in the manufacture of ,Benifuuki' green tea beverage. Among various varieties of tea, the cultivar ,Benifuuki' contains approximately 2% of EGCG3,Me. Ester-type catechins and their epimers increased with the increased extraction temperature of the tea. A tea infusion, extracted at 90 C, strongly inhibited histamine release from mast cells. Furthermore, sterilization affected the catechin content in the manufactured green tea beverage. Sterilization at high temperature promoted the isomerization of catechins and the sterilized green tea beverage had a strong inhibitory effect. When EGCG3,Me, EGCG, epicatechin-3- O -gallate (ECG) and their epimers, GCG3,Me (gallocatechin-3- O -(3- O -methyl) gallate), GCG (gallocatechin-3- O -gallate) and CG (catechin-3- O -gallate) were compared, the anti-allergic effect of GCG3,Me was strongest, and the order of activity was GCG3,Me > EGCG3,Me > GCG > EGCG. We consequently suggest that it was necessary to extract components from tea at the highest temperature possible, and to pasteurize under retort conditions (118.1 C, 20 min), to manufacture functional green tea beverage with an anti-allergic action. Copyright 2005 Society of Chemical Industry [source]

Effects of pulsed electric fields on bioactive components, colour and flavour of green tea infusions

Wei Zhao
Summary Green tea is an unfermented tea containing a higher quantity of bioactive components. In this paper, the effects of pulsed electric field (PEF) treatments on the bioactive components (polyphenols, catechins and free amino acids), colour and flavour of green tea infusions were studied. PEF as a promising non-thermal sterilisation technology could efficiently retain polyphenols, catechins and original colour of green tea infusions with electric field strength from 20 to 40 kV cm,1 for 200 ,s. PEF treatments caused a significant increase in the total free amino acids of green tea infusions. The total free amino acids increased by 7.5% after PEF treatment at 40 kV cm,1. The increase in total amino acids induced by PEF treatment, especially to theanine, is beneficial for the quality of commercial ready-to-drink green tea infusion products. There was no significant effect of PEF treatment at 20 or 30 kV cm,1 on flavour compounds of green tea infusions. However, PEF treatment caused losses of volatiles in green tea infusions to different extents when PEF dosage was higher than a critical level. The total concentration of volatiles lost was approximately 10% after PEF treatment at 40 kV cm,1 for 200 ,s. [source]

The Impact of Grape Skin Bioactive Functionality Information on the Acceptability of Tea Infusions Made from Wine By-Products

Vern Jou Cheng
ABSTRACT:, The effect of information on the health benefits of bio-active compounds on the acceptability of 5 tea infusions made from grape skins generated from wine processing waste (from,Vitis vinifera,var. Pinot Noir and Pinot Gris) was investigated. Samples of tea infusions with natural additives (PNHGT25 and PGGT50) and without additives (control PN, control PG, and PNPG50) were evaluated by 45 in-home consumer panels (30 female, 15 male) before and after information on the health benefits of grape skins were provided. Information significantly increased the overall acceptability, overall aroma, flavor, and aftertaste of the infusions. The results obtained showed a clear tendency toward increased purchase intention (by 29%) when information on the health benefits of the tea infusion samples was provided to consumers. Interactions existed between gender/infusion samples and stage of information on the purchase intention. Females recorded a significant increase (by 53%) in purchase intention, whereas no change in the males' purchase intention was found after information was provided. [source]