Abstract:
Due to the presence of Polyphenols and calcium haze develop and it affects the appeal of
the beverage. Therefore, the effects of pre-treatment of tea with Tannase and Viscozyme
enzymes on the physiochemical and organoleptic properties of cold-water-soluble instant
black tea were investigated. Black tea samples (50 g each) were treated with five different
levels (0.02%,0.04%,0.06%,0.08%,0.1%) of enzymes (dissolved in 150 mL of distilled
water) separately at 40⁰ C for 40 minutes, Then, 150 mL of boiling water was added to
each sample and extracts were obtained after brewing at 95⁰ C for 10 minutes. Extracts
were centrifuged at 3500 rpm for five minutes at room temperature and the supernatants
were obtained. Based on the physiochemical properties like Turbidity, polyphenol
content, total soluble solids. Of supernatants, enzyme levels for pre-treatment were
optimized. Secondly, black tea samples were treated with a combination of optimized
enzyme levels following a similar procedure. Supernatants were freeze-dried and
analyzed for physiochemical and sensory properties. Each experiment was repeated
thrice. Physiochemical and sensory data were analyzed by Duncan Multiple Range test
and Friedman test (p<0.05) respectively. The enzyme level of 0.06% which resulted in the
lowest turbidity by both of the enzymes was selected as optimum. Revealing
improvement in physiochemical properties, the sample treated with enzyme combination
was significantly lower in turbidity (88.2±5.2) and higher in Theaflavin content
(1.3±0.1%) and brightness (88.8±1.4) as compared to the control (99.4±5.5, 1.0±0.1% and
70.2±2.8 respectively). Further, it received higher ranks for sensory properties.
Viscozyme and Tannase pre-treatment of tea extraction improve the quality of ColdWater-Soluble Instant Tea.
Keywords: Instant black tea, Viscozyme, Tannase, Haze
