1Associate Professor, Department of Food Product Development, National Institute of Food Technology, Entrepreneurship and Management - Thanjavur
2Associate Professor, Department of Academics and Human Resource Development, National Institute of Food Technology, Entrepreneurship and Management - Thanjavur
3Associate Professor, Department of Agricultural Engineering, Kalasalingam Academy of Research and Education, Virudhunagar, India
*Corresponding author email address: vchandrasekar@iifpt.edu.in
Online Published on 05 December, 2022.
Coleus (Coleus forskohli), a medicinal crop, contains a bioactive component forskolin, which is extracted and used in several ayurvedic medicines in India. Drying is the primary operation to extract forskolin. In this the study, Coleus was dried in a rotary drier by varying slice thickness (2.5, 5.0, 7.5 mm), drying air temperature (45, 55, 65 oC), and feed volume (50, 60, 70 percent); and the forskolin contents were assessed. The moisture content reduced to 16.55% (d.b.) from 464.97% (d.b.) after rotary drying. The drying time ranged from 300 min to 450 min. The effective moisture diffusivity and activation energy ranged from 1.02 x10−7 mm2s−1 to 1.33 x10−6 mm2.s−1 and 5.39 kJ.mol−1 to 15.57 kJ.mol−1, respectively. Forskolin content in dried root varied from 0.14% to 1.87 per cent. High forskolin content was found in 2.5 mm thick slice dried at 55 oC and 70% feed volume. Analysis of variance showed that forskolin content in dried Coleus root was significantly (p<0.0001) affected by slice thickness and drying air temperature than feed volume (p<0.01).
Coleus drying, Rotary dryer, Effective moisture diffusivity, Forskolin
