Abstracto

Osmotic Dehydration of Radish in Salt and Sucrose Solutions

Dr. A. Nishadh, Limi Mathai

White radish (Raphanus sativus) is a mild-flavoured, very large, white East Asian radish with a wide variety of culinary uses. Osmotic dehydration is a preservation method that offers a high quality product by means of water removal without phase change. This work deals with the studies of osmotic dehydration characteristics of radish in different concentration of osmotic solutions such as salt (3, 6, 9) % and sugar (30, 40, 50)0brix. Radish samples were osmotically dehydrated in osmotic solutions such as salt and sugar with different concentrations at room temperature. Physical, chemical and nutritional analysis was done for the sample and osmotic dehydrated radish. The moisture content, dry matter content, dehydration ratio and rehydration ratio were determined and plotted. From the results it was observed that in the case of moisture content and dry matter content, sugar solution is more effective whereas in the case of rehydration ratio salt solution is best. Therefore applying a combination of these osmotic agents can increase the dehydration effect more. The present study also shows the optimum concentration of osmotic agents at room temperature as 6% for salt solution and 400brix for sugar solution. Also proximate analysis such as moisture content, ash content and ascorbic acid determination were performed for raw and osmotic dehydrated radish and compared it with normal dried radish. Moisture content, ash content and ascorbic acid present in osmotic dehydrated radish was found to be less than that of raw radish and higher than the normal dried radish. This implies that osmotic dehydration retains the nutritive properties of radish than normal drying. Some of these benefits include being able to store radish for longer period of time, maintaining nutritional aspects, flavors and preventing microbial spoilage from occurring.