Concentration-dependent moisture diffusion coefficient estimation in peas drying considering shrinkage: An observer approach. (June 2022)

• Record Type: Journal Article
• Authors: Martínez Vera, Carlos; Vizcarra Mendoza, Mario G.
• Is Part Of: Biosystems engineering. Volume 218(2022)
• Page Start: 256
• Page End: 273
• Publication Date: 2022-06
• Subjects: Diffusion coefficient -- Drying-shrinking -- Non-linear estimators -- Observers -- Peas drying; Bioengineering -- Periodicals; Agricultural engineering -- Periodicals; Biological systems -- Periodicals; Génie rural -- Périodiques; Systèmes biologiques -- Périodiques; 631
• DOI: 10.1016/j.biosystemseng.2022.04.016
• Languages: English
• ISSNs: 1537-5110

Abstract

Abstract : Drying is a widely used process for the conservation of agricultural products. Usually, bio-products such as fruits and vegetables have high initial moisture content and present appreciable volume shrinkage during drying. Shrinkage of biological materials takes place simultaneously with moisture diffusion during drying and thus may affect drying rate. It is important to take in account the shrinking phenomena when determining the moisture diffusion coefficients. This work determined the effective moisture diffusion coefficient in peas ( Pisum sativum ). And its dependency on water concentration. The functional form of this dependency was found by applying a non-linear estimator and, subsequently, refining it through an optimisation procedure. The effect of the presence of deterministic perturbations in the experimental measurements on the estimation process was also analysed. This methodology could be equally applied to hydration processes that undergo swelling. Highlights: Water diffusivity at constant temperature determined with a non-linear estimator. Model for the diffusion coefficient dependency on concentration determined. Material shrinkage considered in the determination of the diffusion coefficient. Robustness of the method in the presence of perturbed measurements analysed.