Determination of Green Tea Recovery Percentage and Its Relation to Different Weather Parameters

Aims: Green tea is one of the most popular drinks and millions of cups are consumed every day in entire world. In Bangladesh, people mainly prefer CTC (Crush-Tear-Curl) black tea but now-a-days health conscious people are being habituated to green tea due to its beneficial effect to health. Since our green tea production is very little compared to black tea production, our concept and knowledge about green tea is also very low. This experiment was conducted with two main objectives: to determine the green tea recovery percentage and to find its relation to different weather parameters.

Study Design: This experiment was conducted by following Factorial Completely Randomized Design (CRD) with four replications.

Place and Duration of Study: This experiment was conducted at Miniature Factory of Bangladesh Tea Research Institute (BTRI) Sreemangal, Moulvibazar-3210 from March 2017 to November 2017.

Methodology: BTRI recommended green tea manufacturing process (Green Leaves→ Steaming→ Cooling→ Rolling→ Drying) was followed in this experiment to calculate the recovery percentage. Weight of green leaves after each stage and recovery percentage were calculated. Monthly weather data of four parameters: temperature (°C), rainfall (mm), relative humidity (%) and sunshine hour were also collected. Correlation Coefficient (r) was calculated by Pearson’s mathematical formulation to quantify the degree of relationship. Linear regression equation was also generated to predict recovery percentages against different weather parameters only when the relationship was significant.

Results: In case of BTRI recommended green tea manufacturing process the average recovery percentage was 19.19% with an average moisture content of 3.72%. Among four weather parameters, temperature (°C) has negative insignificant (correlation coefficient, r=-0.43 and P=0.2523) relation on recovery percentage. But there was a strong significant (P=0.000146) negative effect (r=-0.942) of rainfall on recovery percentage. While a moderate non-significant (P=0.322807) negative relation (r=-0.37) of relative humidity and a considerable high positive non-significant (P=0.073687) relation (r=0.62) of sunshine hour on recovery percentage was found in this study.

Conclusion: Green tea recovery percentage was 19.19% with an average moisture content of 3.72% which can be different with different weather conditions in every month. Among four weather parameters, mainly rainfall was responsible for the variation of recovery percentages in different months.