Mass transfer kinetics and process optimization of osmotic dehydration of Kinnow mandarin ( Citrus reticulata ) peel

Abstract

Kinnow mandarin (Citrus reticulata) peel, an agricultural solid waste of the Kinnow juice processing industry, was studied to understand the mass transfer kinetics during osmotic dehydration and its process optimization. The experiments were conducted in sucrose (40, 50, and 60° Brix) at different temperatures of 40, 50, and 60°C and process duration of 0–240 min. The Central Composite Design was used for the optimization of the osmotic dehydration process with the variables, such as blanching time (3–6 min), solute concentration (40–60° Brix), process temperature (40–60°C), and process duration (120–150 min). Increased water loss (28.70 g/100 g) and solid gain (12.90 g/100 g) were observed at 60° Brix and 50°C in 240 min. The Penetration model was the best-fitted model for water loss and solute gain. The osmotic dehydration process at 60° Brix and 48°C for 150 min with blanching (3.60 min) yielded water loss (32.40 g/100 g), solute gain (14.60 g/100 g), ascorbic acid (17.50 mg/100 g), and overall acceptability (6.50). Overall, the findings concluded that the understanding of process parameters can be used as the basis for the sustainable valorization of Kinnow peel using osmotic dehydration. Practical applications Currently, valorization of agri-food waste becomes a major challenge and thus we studied to understand the mass transfer kinetics during the osmotic dehydration and its process optimization of Kinnow mandarin (Citrus reticulata) peel. The findings suggested that the optimization of osmotic dehydration process parameters and kinetic modeling may be useful for the valorization of Kinnow peel in the development of food products.