A Review on Osmotic Dehydration of Fruits and Vegetables: An Integrated Approach

Abstract Osmotic dehydration is a simultaneous mass transfer process which mainly promotes the flow of water molecules from the food to osmo‐active solution and some migration of solutes from the solution into the food, thus maintaining good organoleptic and functional properties in the finished product. This paper presents mechanism of osmotic dehydration and recent developments regarding the factors affecting osmotic dehydration process viz., pretreatment factors (blanching, coating, ultrasound treatment, high pressure processing, pulsed electric field effect, etc.), product‐related factors and osmotic solution related factors (temperature of osmotic solution, concentration of osmotic agent, type of osmotic agent, agitation/stirring process during osmotic process, osmotic solution and food mass ratio). The details on mathematical modeling of mass transfer during osmotic dehydration of foods and benefits of osmotic dehydration which includes energy saving methods and quality of final product are reviewed. Practical Application Osmosis is a physical phenomenon that has been extensively studied in various disciplines of science and engineering. Osmotic dehydration has diverse applications in fruits and vegetables. Thus it can be used to decrease the post harvest losses. Being a simple process, it facilitates processing of fruits and vegetables with retention of initial fruit characteristics viz., colour, aroma, texture and nutritional composition. Since no preservative was used, it does not adversely affect the human body. This process could be used on small scale for development of self‐entrepreneurs and home scale industries. The mathematical models can be used for understanding the mass transfer phenomenon during the process. The economic interest relates to the reduced energy consumption as compared to conventional drying. This review serves to provide an updated status on osmotic dehydration and its research gap which is useful for academics, research purpose and processing industries.