Effect of outlet temperature and total soluble solid in 2-stage spray dryer on black tea powder extract production

The black tea powder extract produced through the spray drying technique is an alternative to tea steeping or brewing in the industry. The production of black tea powder extract using the 2-stage spray dry method still has problems such as different colour, product swelling or inflate and blocking. To determine the source of the problem, this study used varied outlet temperatures 105°C, 110°C, 115°C, 120°C and total soluble solids (TSS) 31.3, 35.2, 37.2, 43.9, 44.1, 47.4. Spraying through 2-stage spray dryer with combi fluid bed and high nozzle pressure atomizer model SC 40 SDX III by Delavan. The results show a significant difference between the outlet chamber temperatures with the flowrates, the pressures, and the densities. An increase in outlet temperatures by a multiple of 10°C can significantly reduce the pressure and the flow rate, while the temperatures multiple of 20°C can significantly reduce the densities, but not for the moisture contents and the powder colours. Changes in the outlet temperatures did not have a 0.2% effect on the steeping colours but were affected by TSS. The higher TSS's value gives an increase in flow rate, pressure, moisture content and steeped powder colours of 0.2%.