Influence of inner structure, porosity and degradation kinetics on pectin extraction from fruit peels in agitated-batch extractor: Computational modelling via lattice Boltzmann method

Abstract

• An in-house lattice-Boltzmann code has been improved to simulate pectin extraction. • If inner structure modelling is needed, whole peel quantities must be compensated. • Homogenous peel assumption can be invoked to simplify pectin extraction model. • Porosity and pectin degradation should be modelled inside peel flakes. An in-house lattice-Boltzmann computer code has been continuously developed to simulate agitated-batch pectin extraction from fruit peels. While in preceding works fruit peels have been mathematically modelled as homogeneous thin flakes without pectin degradation in interstitial fluid, the present work considers its inner structure and porosity as well as pectin degradation therein. Consequently, initial and boundary conditions originally imposed were revisited and further model parameters arose such as albedo layer fraction (in relation to whole thickness) and peel porosity. Governing equations for protopectin and pectin concentrations were either adapted or extended in the extant in-house lattice-Boltzmann computer code. Numerical simulations showed that proposed model extensions are indeed influential, which suggests that original values of process parameters should undergo new fine-tuning if a more comprehensive model for pectin extraction is used.