Characterization of freeze-dried ginger slices with carboxymethyl cellulose as potential coating material prior to osmotic dehydration

Abstract

Edible coating prior to osmotic dehydration has been studied extensively to enhance the performance of drying in food products. In this study, the effectiveness of carboxymethyl cellulose (CMC) coating before osmotic dehydration of ginger slices on the mass transfer was studied. The samples were then dried using a freeze dryer, and the changes in colour, structural, and chemical components were determined. Coated ginger showed a minimised solute gain without affecting the water loss performance. The mass transfer kinetics were fitted successfully using the Magee model. After the freeze-drying process, the combination of CMC and osmotic dehydration as a pre-treatment influenced the colour properties and the microstructure without altering the functional groups. From these findings, it shows that CMC coated ginger slices and osmotic dehydration prior to freezedrying can be an alternative to meet the demands of current consumers, and thus be a promising route for obtaining dried ginger.