Impact of Inlet Drying Temperature in Endless Chain Pressure Dryers on the Quality Characteristics of Leafy Type of Tea Produced Using Different Leaf Standards

Abstract

This study was carried out to investigate the appropriate higher inlet drying temperatures in Endless Chain Pressure (ECP) dryers to assess the improvement of quality characteristic of Orthodox type of tea of seven grades (OP, OP1, PEKOE, FBOPF, FBOP, FBOPF1 and OPA) produced using three different standards of leaves. Selected Leaf standards were 40%, 50%, and 60% of good leaves (fine plucking of two leaves and a bud). Two different drying temperatures, 205 o F as the control and 230 o F as the treatment, selected for this study. Pilot scale Orthodox rollers with a capacity of 15 kg withered leaves were used to undertake Pure Orthodox manufacturing process. Experiment was conducted in triplicate for each leaf standard at two different drying temperatures. Dried tea samples were separated into seven grades namely OP, OP1, PEKOE, FBOPF, FBOP, FBOPF1 and OPA. Graded tea samples were organoleptically assessed for their liquoring properties such as infused leaf color, liquor color and strength, quality and the appearance of graded tea by professional tea tasters" in Colombo. Results revealed that there was no significant difference in liquoring properties of made tea produced at higher drying inlet temperature against dryer temperature of 205 o F for three different standards of leaf. It indicates that higher inlet drying temperature does not influence the overall quality of the liquor. However, a trend was observed that tea produced with 60% good leaves, gave better

Tea Harvesting and Processing Techniques and Its Effect on Phytochemical Profile and Final Quality of Black Tea: A Review

“…Compared to the 96 • C dryer temperature, a high inlet drying temperature did not affect the quality of the tea. A higher inlet temperature could enhance the appearance when there are only 40% excellent leaves [167]. Quality may be improved by exposing tea constituents to temperatures of up to 120 • C for less than a minute.…”

Application of response surface methodology to optimize the drying condition of black tea using superheated steam dryer

“…Special attention had been paid to processing technologies because they directly influence the quality of tea produced (Botheju, Amarathunge, & Abeysinghe, 2011). The drying process is especially responsible for finalising the flavour of tea and removing undesired moisture to give a longer shelf life (Kavish, S. Botheju, & De Silva, 2016). Drying is an energy demanding process that consumes around 10-15% of national energy in most developing countries (Mujumdar & Devahastin, adverse environmental impacts in terms of deforestation and air pollution (the release of carbon dioxide after burning).…”