Effect of conventional and solar hybrid drying on quality characteristics of turmeric

Experiments were conducted to compare the quality characteristics of turmeric under conventional and solar hybrid drying in order to find the most suitable method. The conventional drying was done in open sun, improved sun drying and mechanical drying. The solar hybrid drying included four combinations viz., solar drying with electrical backup with and without insulation and solar and electrical drying independently. Both, the physical and chemical quality characteristics were studied. Color characteristics were observed to be better in the solar hybrid drying due to the protection of pigment in the absence of direct exposure to sun. The highest oleoresin (13.05%) and curcumin content (4.03%) were observed in the solar hybrid dryer with usage of auxiliary heating unit. The final recovery (highest in ‘TDS'at 19.82%) and polishing loss (lowest in ‘IDW'at 6.33%) in all the drying methods was in permissible limits and hence solar hybrid drying was observed to be a better option for drying of turmeric to improve its quality characteristics.