Document Type : Research Paper
Authors
1 Msc. Student, Department of Food Science and Technology, Islamic Azad University, Science and Research Branch, Tehran, Iran
2 Department of Chemistry, Islamic Azad University, Science and Research Branch, Tehran, Iran
3 Department of Food Science and Technology, Islamic Azad University, Science and Research Branch, Tehran, Iran
Abstract
After water, tea is the most consumed beverage around the world. Phenolic compounds constitute 50-70 % of tea water extract that Theaflavins (TF) and Thearubigins (TR) among them are of most important polyphenols as quality parameters of black tea. Agroclimatic conditions, tea variety and geographical origin are of effective factors on tea quality. This study was undertaken to quantify seasonal variations in quality- related, biochemical, and sensory parameters in manufactured orthodox Iranian tea over various months (June, July, August, September and October). TF, TR, TRSI and TRSII, total color, total polyphenols and brightness were measured by spectrophotometer method and the tea quality was estimated and scored by professional tea tasters. According to the results of ANOVA, phenolic compounds significantly differed in different tea plucking seasons (P<0.05). Drink obtained from green leaves in July tea plucking season had the highest total polyphenols (15.83%), Theaflavins (22.33 µmol/g), total color (3.01%) and brightness (28.85). Results of Pearson's correlation coefficients showed that correlation of total TR and TRSII with brightness was not significant while other measured parameters showed a significant correlation to each other. In view point of tea tasters, tea obtained from July and August had the highest total sensory scores while tea obtained from June received the highest tea aroma score. Spearman rank correlation coefficients indicated that there was no significant correlation between tea aroma and other sensory attributes while mutual correlation of other sensory attributes was positive and significant. This suggests that tea with high chemical quality should have good individual tea sensory attributes.
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