Tea quality: the changing scenario and improvement through process optimization

Abstract

Quality of tea is an integrated perception of appearance, color brightness, strength, flavour and aroma. The chemical basis of quality in tea is the chemical composition and their levels in tea liquor that produces the distinct and desired effect on palate and nose. In addition, quality is also driven by market requirement based on the consumers’ choice. The factors that affect consumers’ perception of food and food quality are numerous. Many of these factors are intrinsic to any type of food i.e. related to its physicochemical characteristic which includes raw material, processing technology etc. These variables in general regulate the overall sensory characteristics of the finished product and its acceptability by consumers. To identify the group of chemical constituents that determine the various aspects of market assessment of made tea, a study was undertaken. Thus the chemical basis of quality is the presence of certain chemical components at a minimum threshold level to create a positive effect on quality. A correlation between chemical constituents and quality and clearly established that theaflavins and thearubigins are the major factors in determining liquor characteristics has been alrady establihsed. In this paper the critical role of theaflavin and its fractions and thearubigins fractions have been emphasized using latest analytical tools to have a better insight into quality. In addition to this, critical role of caffeine and chlorophyll degraded productsto retain overall cup character and appearance. Role of processing technology in enhancing threshold level of different chemical constituents responsible for quality with reference to withering and fermentation based on the biochemical mechanism etc will be discussed. In this connection we are going to highlight biochemical factors regulating the overall chemical
reactions due to rate of loss of moisture and temperature during withering and also management of air and temperature in CFM on the cup character of made tea. Attempt has been made to determine the minimum threshold level of some biochemical parameters directly responsible for quality other than the FSSAI/PFA parameters.

Keywords: Quality, biochemical parameters, theaflavins, thearubigins