LAUSR

Abstract An infrared assisted with hot air dryer (IRHAD) was designed and developed to retain the quality of turmeric during drying. Drying experiments were conducted at three different mode of operation [infrared assisted with hot air drying (IRHAD), infrared drying (IRD), and hot air drying (HAD)] and three different drying temperatures (50, 60 and 70oC) at fixed air velocity of 2 m/s. It was observed that IRHAD at 70oC showed higher drying rate and recorded 26.98% and 35.21% lesser drying time than IRD and HAD, respectively. An increase in drying temperature (up to 60oC) increase the curcumin, oleoresin, colour and starch content and further increase in temperature degrades the quality of the turmeric. IRHAD provided maximum retention of curcumin, oleoresin, and starch content and less colour deterioration at 60oC temperature compared to IRD and HAD. The drying methods and drying temperatures have significant effect (P≤0.01) on the quality parameters investigated. IRHAD with the drying temperature of 60oC could be the suitable operating condition to produce better-quality turmeric.