Osmotic Dehydration Kinetics of Pumpkin Fruits Using Ternary Solutions of Sodium Chloride and Sucrose

Abstract

The objective of this work was to obtain experimental data and modeling of osmotic dehydration kinetics of pumpkin fruits (Cucurbita pepo L.) with aqueous NaCl/sucrose solutions. For this purpose, effective diffusion coefficients for water, sucrose, and NaCl were calculated by means of a simple model based on Fick's second law. Water loss achieved 80%, sucrose 13%, and NaCl 6% of the initial sample weight. Effective diffusion coefficients ranged from 0.58–1.40 × 10⁻⁹ m²/s, 0.75–1.23 × 10⁻⁹ m²/s, and 2.60–4.11 × 10⁻⁹ m²/s for water, sucrose, and NaCl, respectively. The proposed model gave a good correlation of the experimental data. The quality of the operation was evaluated by analysis of the values of WL/SG ratio.

Keywords:

• Diffusion coefficients
• Salt
• Squash
• Solids gain
• Sugar
• Water loss

ACKNOWLEDGEMENTS

The author Luis Mayor acknowledges SFRH/BD/3414/2000 PhD grant to Fundaçao para a Ciência e a Tecnologia, Portugal, as well as the facilities provided by the Departamento de Enxeñaria Química at Universidade de Santiago (USC, Spain).

Notes

∗∗∗, ∗∗, ∗ Coefficients significant at 0.1, 1, and 5% confidence level, respectively.