Physical behavior of highly deformable products during convective drying assessed by a new experimental device

ABSTRACT

This article presents an experimental device specially designed for the continuous measurement of mass and dimensions of samples submitted to convective drying. This experimental device consists of a magnetic suspension balance and an image acquisition system. The sample deformation is determined by image correlation using a custom software. The entire system is able to achieve accurate mass and dimension measurements over a wide range of temperature and relative humidity. To present the potential of this equipment, experimental data of highly deformable food products (potato and apple) submitted to several drying conditions are presented. The obtained results confirm that it is required to consider the actual sample surface to determine the mass flux. This allowed a first drying stage to be observed for potato. Clear differences in physical behavior of these two vegetable products were also observed, for example, an isotropic shrinkage behavior for potato and an anisotropic behavior for apple. These results were explained by the anatomical structure of the products.

KEYWORDS:

• Apple
• highly deformable matters
• image acquisition
• image correlation
• magnetic suspension balance
• parenchyma cells
• potato

Additional information

Funding

This research was supported by Capes Foundation (Brazil) and Erasmus mundus exchange program (European funds).