Summary

Tea is the major export product in Sri Lanka. Export of quality tea will raise the market price and income to the country economy. The characteristic color, aroma, and taste of black tea are developed during fermentation stage.
Current methods trust human experience in detecting color variations when deciding optimum fermentation levels consequently involve high r isk when controlling quality. However, a successful method to monitor fermentation stage is not yet developed. Therefore, this project proposes an accurate, simple to operate yet reliable device to monitor fermentation process of black tea manufacturing to ensure optimum fermentation to maintain constant quality.
The method proposed in this project involves monitoring of color changes during fermentation using image processing techniques instead of human eye. The first stage of the project is focused on r ecording changes in Red, Green, Blue (RGB) and other image features of tea particles with fermentation time. Simultaneously, chemical changes during fermentation were recorded using UV visible spectroscopy and electrochemically. Then changes in image prope rties will be correlated with chemical changes during fermentation.
The expected outputs of this project will be prediction of fermentation level of a given image and electrochemical response and predict total duration of fermentation for a desired TR/TF content. This device will aid factory officers in monitoring fermentation as well as predict time suitable fermentation of given tea quality (TF/TR, color and taste).Since the system do not require special training for the factory workers and simplified in strumentation will be attractive features. Finally, higher quality tea resu lts in higher price thus contribute to country economy.

Objectives

The overall aim of this project is to develop an automated methodto monitor and predict the optimum duration for fermentation of black tea independent from human intervention.

Following are specific objectives of the project in order to attain the overall aim of developing an automated system.

1. 1. Measure levels of polyphenol compounds, TR, and TF content spectroscopically while recording the temperature, height of tea leaves spread and humidity during. Also, moisture content of tea leaves coming to withering stage is noted as well. Then develop a mathematical relationship to predict the expected duration of fermentation (for certain level of polyphenol content) when ambient temperature and humidity parameters are given.
   2. Develop a prototype of an automated image acquisition system and electrochemical system which can acquire images and record chemical changes during fermentation. Then use the device to calculate the degree of fermentation and recommend duration of fermentation
   3. Develop a relationship between changes in polyphenol content during fermentation with change in red, green, and blue (RGB) and other features (entropy, standard deviation, kurtosis, etc) of digital images taken during fermentation.
   4. Measure electrochemical changes in polyphenol content during fermentation with recording differential pulse voltammetry (DPV) or recording linear sweep voltammetry with time. Then calibration of the electrochemical data according polyphenol content measured with ISO 14502-1
   5. Test the validity of the developed system with professional tea tasters, factory managers who have long experience on black tea processing.

Major Equipment Facilitated by Grant