Shrinkage Characteristics and Porosity of Pears during Drying

Abstract

The high moisture content of pears (about 80%) results in a high degree of shrinkage when drying takes place, which strongly affects the fruit structure and quality. The aim of the present work was to study the shrinkage characteristics of pears during air drying by evaluating their dimensions and volume along the drying process and by predicting particle and bulk densities as well as porosity as a function of material moisture content. The latter properties were estimated using a mathematical model available from the literature whose parameters were either directly measured or determined by fitting some of the equations of the proposed model to the experimental data. The results predicted were subsequently validated by independent measurements.

Keywords:

• Density
• Pear drying
• Porosity
• Shrinkage

Notes

*Measured by gas picnometry.

**Measured by liquid picnometry.

Dedicated to the memory of Professor José Almiro e Castro.