A comparative study on drying of basil leaves

Basil is a popular aromatic and annual herb growing in many regions of the world.  Immediately after its harvesting, the highly perishable raw material, i.e. leaves, have to be preserved against deterioration and spoilage.  More often, during peak period, most of the crop is lost/wasted due to lack of proper post-harvest processing techniques.  Drying is by far the most widely used treatment, which needs to be performed very carefully and preciously so as to preserve the aroma and color of the leaves.  Various drying treatments and experimental methods viz., solar drying, tray drying, vacuum drying and fluidized bed drying were carried out at the temperatures of45°C,55°Cand65°Cto find and suggest the optimum drying condition for acquiring quality dried basil leaves.  Results have revealed that ‘total drying time’ is considerably reduced with the increase in drying air temperatures from45°Cto65°C.  It could be recommended that for the best drying of basil leaves, the drying operation needs to be carried out in the fluidized bed dryer at 45ºC for 30 s steam blanched sample ensuring the best results in quality of basil leaves as compared to other methods and treatments whatever considered during present study

Drying Characteristics of Rose Flowers

Full boom rose was dried by employing different drying methods such as hot air drying at 40, 50 and 60 0C, microwave oven drying with silica gel at 50 0C, vacuum drying at 40 0C and 760 mm Hg pressure besides solar and shade drying to find out the most suitable method and parameters. The Exponential and Page’s model were tested for their validity. Page’s model was found to fit best. The maximum and minimum drying time for rose flowers was 5 days in shade and 13 minutes in microwave oven. Drying of rose flowers under all treatments completely took place in the falling rate period. Maximum overall drying rate of 5.87 %/min was during microwave oven drying with silica gel at 50oC, followed by vacuum drying at 40oC. Microwave oven drying of rose flowers at 50oC with silica gel was found the best from the reduction in size point of view