OSMOTIC DEHYDRATION OF PAPAYA: CHARACTERIZATION AND MODELLING OF MASS TRANSFER KINETICS

Abstract

Introduction:
Fruits and vegetables are characterized by their rapid deterioration; dehydration is an option to reduce these losses. Osmotic dehydration and power ultrasound can be used as pretreatment for convective drying.
Objective:
To characterize the osmotic dehydration of papaya based on the effect of the operating variables, as well as model the kinetics of wáter loss and solid gain.
Material and methods:
The effect of the operating variables, concentration of a sugar solution (30, 40 and 50 ⁰Brix) and treatment time (2, 4 and 6 h), on the osmotic dehydration of papaya cubes (Carica papaya L.) Maradol Roja variety with and without power ultrasound assistance was investigated. Empirical models were fitted to describe the mass transfer kinetics in the fruits.
Results and discussion:
Time was the most influential variable factor on water loss and solid gain. Ultrasound-assisted osmotic dehydration markedly reduced treatment time. The solids gain was lower than the water loss. The models considered describe the kinetics of mass transfer in the fruit.
Conclusions:
The best conditions for osmotic dehydration were 50 ºBrix and 6 h. The use of ultrasound reduced treatment time to 60 minutes. The Peleg model reported the best fit to the experimental data.