CZECH JOURNAL OF FOOD SCIENCES, cilt.34, sa.5, ss.397-405, 2016 (SCI-Expanded)
Although the quality of black tea mainly depends on the constituents and conditions of raw material, the manufacturing process also plays a significant role in obtaining high quality tea products. In this study, microwave technology is used for black tea production in withering and drying steps to increase its quality characteristics. Total polyphenols, theaflavin (TF), total thearubigins (TR), liquor brightness, and total colour were measured by spectrophotometric methods. Total antioxidant activity was determined by the DPPH method. Microwaved black teas showed higher amounts of quality constituents with similar phenolic contents and antioxidant activities compared to commercial Turkish teas. The plucking season was also found to have an effect on these constituents of black teas. Generally, microvawed black teas have higher spectrophotometric brightness and lower total colour values. The analytical and sensory results showed that using a microwave dryer during the black tea process is highly acceptable in respect to these quality parameters when compared with other commercial black teas obtained from the markets in Turkey and other countries.