Cold-air assisted fluidized bed tea production cycle as a novel method

Abstract

Recent research reveals that basic low temperature processes have significantly preserve to the biomaterial quality. In the production process of the tea plant, which is known for its bioactive characteristics, many basic processes that are thought to affect the bioactivity are applied. In this study, the applicability of some chemical properties and sensory qualities of freeze withering (LTwh), rotary curling, cold air assisted fluidized bed drying applications in white and black tea production were investigated. For this purpose, 300 g of buds harvested in the first shoot period were used in the production of white tea (Wt), while fresh tea samples collected as three leaves of the same weight were used for the production of Black tea (Bt). In this context, the samples collected for both trials were frozen at (-18 ºC) degrees after harvesting and thawed again at refrigerator temperature as a withering process. The rolling process was carried out using a rolling unit with a rotating cabinet (40 rpm/min, 32ºC, 8 s, 90 rh) specially designed for the Bt samples after the withering. During drying, the same drying parameters of both products (Wt, Bt) were applied in a fluidized bed system (60, 40, 25, 10ºC) with a high air velocity (± 5 m/s). In this regard the withering, rolling (only for Bt), fluidisation value, cold air assisted fluidised bed drying, brewing, physical, chemical and sensory characteristics of Wt and Bt were investigated.