Journal of Food Processing & Technology

Abstract

Effect of Drying Methods on Quality Characteristics of Medicinal Indian Borage (Coleus aromaticus) Leaves

Suchismita Dwivedy, Kalpana Rayaguru and G R Sahoo

 Indian Borage (Coleus aromaticus) leaves are very rich in medicinal qualities. Due to low keeping quality, heavy quantities of Coleus leaves go as waste every year. If proper drying methods are scientifically standardized, the leaves can be processed both at garden and orchard level and the grower can earn more profit. The present study is an attempt to assess the effect of selected drying methods on the quality characteristics of the leaves. The drying methods considered were hot air drying (50°C -80°C), fluidized bed drying (50°C -80°C), and microwave drying(180-900W). The dependent parameters were total drying time, therapeutic quality (total phenolics, antioxidant property), and sensory property (shape, colour, aroma and overall acceptability). Effect of power level and temperature on quality characteristics of dried products has been analyzed to determine the optimum drying conditions. Considering the total drying time, therapeutic and sensory attributes of the dried leaves, it is proposed to dry the leaves at 60°C and 540W in hot air dryer and microwave dryer respectively to obtain an acceptable product. Overall analysis of the drying behaviour and quality characteristics of dried leaves indicated that the microwave drying could preserve maximum therapeutic quality followed by hot air drying. As the leaves lost most of the medicinal components for which these are valued in a fluidized bed drying, the scope of fluidized bed drying for preservation of leaves was ruled out.