Infrared assisted hot air dryer for turmeric slices:Effect on drying rate and quality parameters

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 70 degrees C) at fixed air velocity of 2 m/s. It was observed that IRHAD at 70 degrees C 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 60 degrees C) 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 60 degrees C 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 60 degrees C could be the suitable operating condition to produce better-quality turmeric.

Automated summary

The study demonstrated that IRHAD at 70 degrees Celsius was the most effective drying method, reducing drying time significantly compared to IRD and HAD; 60 degrees Celsius was found to be the optimal drying temperature for improving the quality of turmeric; the drying method and temperature had a significant impact on the quality parameters of turmeric.