Efeects of process variables on mass transfer during osmotic dehydration of ginger slices using carboxymethyl cellulose as an edible coating material

Fresh ginger (Zingiber officinale) has a high moisture content, which makes it susceptible to deteriorate. Therefore, drying is an important processing method for water removal that reduces water activity and extends the shelf life of food products. On top of that, it can help to ensure a more sustainable food system. Edible coating prior osmotic dehydration has the potential to enhance the drying performance of ginger slices. In this study, the effect of carboxymethyl cellulose (CMC) as an edible coating on mass transfer of ginger slices during osmotic dehydration was quantitatively investigated. The influences of CMC concentrations (1-3% w/w) as edible coating solution, sucrose concentrations (40-60% w/w) with 2% w/w salt as osmotic solution, and immersion time (30-150 min) on water loss and solute gain during osmotic dehydration of ginger slices were investigated using response surface methodology. It was found that only CMC concentration had no significant effect on the water loss whereas in solute gain, all the process variables were significant. The optimum conditions to obtain water loss of 53% with a solute gain of 4.5% were found to be at 2.7% w/w CMC coating, immersed in 50% w/w sucrose solution with 2% salt solution for 150 min. The establishment of this process condition can provide useful information for further drying to achieve the energy-saving process. � Penerbit UMT.