Induction Heating Assisted Foam Mat Drying of Papaya Pulp: Drying Kinetics, drying modeling, and Effects on Quality Attributes

Abstract

The study was focused on investigating the drying kinetics, drying modeling and quality parameters of induction heating assisted foam mat dried papaya pulp powder. Variable parameters in induction drying were induction voltage (150, 175 and 200 V) at 100º C and foam-mat thickness (4, 6 and 8 mm). Both the independent variables had a pronounced effect on drying characteristics of papaya pulp foam. For comparison, 6mm thick foam was dried at 100º C air temperature. Seven drying models were fitted to obtain the models that fit best. The selection of model was done on the basis of certain statistical parameters. Midilli-Kucuk Model was found to be the best in all cases except at thickness 6 mm and 200 V where Wang and Sing model exhibited best results. Effect of drying parameters on properties of reconstituted papaya pulp powder was studied by applying face-centered design of response surface methodology. Modified quadratic models were significant at  p≤0.05 for pH, Vitamin C,  total sugar, reducing sugar and TSS, but not for color change. The optimum values of input voltage and foam-mat thickness were 150 V and 8 mm, respectively which would yield dried papaya powder of pH 4.6; reducing sugar 3.55%; ascorbic acid 126.42 mg/100 mL; color change 10.26 with desirability 0.889.