A coarse-grained multiscale model to simulate morphological changes of food-plant tissues undergoing drying

Numerical modelling has emerged as a powerful and effective tool to study various dynamic behaviours of biological matter. Such numerical modelling tools have contributed to the optimisations of food drying parameters leading to higher quality end-products in the field of food engineering. In this context, on of the most recent developments is the mesh-free based numerical models, which have demonstrated enhanced capabilities to model cellular deformations during drying, providing many benefits compared to conventional grid-based modelling approaches. However, the potential extension of this method for simulating bulk level tissues has been a challenge due to the increased requirement for higher computaional time and resources. As a solution for this, by incorporating meshfree features, a novel coarse-grained multiscale numerical model is proposed in this work to predict bulk level (macroscale) deformations of food plant tissues during drying

A multiscale coarse grained model for simulating mechanical responses of plant food tissues

Plant food materials are highly sensitive to the external mechanical responses. Simulation of the material behaviour under mechanical loading is important in many engineering applications. Several researchers have used tissue based (macroscale) and cellular based (microscale) numerical models to assess the plant material behaviour. In doing so, generally, finite element modelling and meshfree based discretization strategies are commonly used and the latter has been proven to be more flexible, accurate and more robust in numerical simulations. This study aims to develop a coarse grained (CG) model for a cellular system of plant food tissue in microscale. The basic idea here is to maintain the accuracy given by the cellular scale while minimizing the computational cost for the simulations. The developed model accounts for the deformation of a coarse grained system under an external mechanical load. In order to represent the viscoelastic behaviour of a plant food material, we use a spring damper system connected to coarse grained beads. The model predictions show a satisfactory agreement with the morphological changes given by the cellular model. This developed CG model has laid a solid foundation for the further development of the multiscale model for the plant tissue

A 3-D meshfree numerical model to analyze cellular scale shrinkage of different categories of fruits and vegetables during drying

In order to optimize food drying operations, a good understanding on the related transport phenomena in food cellular structure is necessary. With that intention, a three-dimensional (3-D) numerical model was developed to better investigate the morphological changes and related solid and fluid dynamics of single parenchyma cells of apple, carrot and grape during drying. This numerical model was developed by coupling a meshfree particle based method:Smoothed Particle Hydrodynamics (SPH) with a Discrete Element Method (DEM). Compared to conventional grid-based numerical modelling techniques such as Finite Element Methods (FEM) and Finite Difference Methods (FDM), the proposed model can better simulate deformations and cellular shrinkage within a wide range of moisture content reduction. The model consists of two main components: cell fluid and cell wall. The cell fluid model is based on SPH and represents the cell protoplasm as a homogeneous Newtonian liquid. The cell wall model is based on a DEM and approximates the cell wall to an incompressible Neo-Hookean solid material. A series of simulations were conducted to mimic the gradual shrinkage during drying as a function of moisture content

A coupled SPH-DEM model for fluid and solid mechanics of apple parenchyma cells during drying

A coupled SPH-DEM based two-dimensional (2-D) micro-scale single cell model is developed to predict basic cell-level shrinkage effects of apple parenchyma cells during air drying. In this newly developed drying model, Smoothed Particle Hydrodynamics (SPH) is used to model the low Reynolds Number fluid motions of the cell protoplasm, and a Discrete Element Method (DEM) is employed to simulate the polymer-like cell wall. Simulations results reasonably agree with published experimental drying results on cellular shrinkage properties such as cellular area, diameter and perimeter. These preliminary results indicate that the model is effective for the modelling and simulation of apple parenchyma cells during air drying

Numerical modeling of morphological changes of food plant materials during drying

Food plant materials, particularly fruits and vegetables, when undergoing drying are subjected to higher levels of morphological changes, leading to alteration of various physical properties characterizing the dried food product. The main factors driving such morphological changes are the moisture content, drying temperature, atmospheric conditions, rate of moisture removal, and properties of the food plant variety.Prediction of such morphological changes is critical for improving the product quality and processing efficiency in food engineering. In that context, different modeling techniques are being researched, each having its own pros and cons depending on the fundamental nature of the technique and its level of advancement achieved, targeting a given application. Among these modeling techniques, numerical modeling has gained considerable attention since the recent past, and which holds true for the present too. In this background, this chapter initially presents an overview of the different modeling techniques used in the field, and then it specifically presents a novel numerical modeling technique available its key applications, limitations, and future prospects

Modelling 3-D cellular microfluidics of different plant cells for the prediction of cellular deformations under external mechanical compression: a SPH-CG-based computational study

Computational modelling of plant cellular materials and relevant mechanics are of interest in numerous research fields. Depending on the complex fluid and solid mechanics involved, there are many numerical modelling approaches applicable in the development of such computational models. This research investigation focuses on computational modelling three-dimensional (3-D) microfluidics of parenchyma cells of three different plant cellular materials: apple, potato and grape with the intention of studying corresponding physical deformations under external mechanical compression which potentially can derive valuable insights about processing of such plant materials. A coupled Smoothed Particle Hydrodynamics (SPH) and Coarse-Grained (CG) approach has been utilised to numerically model the cell fluid and cell wall mechanics, respectively. Quantitative simulation results indicated almost similar cell deformations yielding to top and bottom flat surfaces. In terms of stress-strain behaviour, apple and grape cells revealed stiffer behaviour relative the potato cell. It is evident based on this study that depending on the differences of physical properties of plant cells, their behaviour under compression varies. Findings of this research can be potentially beneficial in further studies towards prediction of 3-D tissue deformation under external mechanical loading

Application of a coupled smoothed particle hydrodynamics(SPH) and coarse-grained (CG) numerical modelling approach to study three-dimensional (3-D) deformations of single cells of different food-plant materials during drying [ArticleFirst]

Numerical modelling has gained popularity in many science and engineering streams due to the economic feasibility and advanced analytical features compared to conventional experimental and theoretical models. Food Drying is one of the areas where numerical modelling is increasingly applied to improve drying process performance and product quality. This investigation applies a three dimensional (3-D) smoothed particle hydrdynamics (SPH) and coarse-grain (CG) numerical approach to predict the morphological changes of different categories of food-plant cells such as apple, grape, potato and carrot during drying

Application of 3D imaging and analysis techniques for the study of food plant cellular deformations during drying

In this investigation, novel 3D imaging and image-analysis tools have been used to observe the deformations of food-plant tissues and single cells during convective air drying at 70°C. A comprehensive investigation was performed to qualitatively and quantitatively analyze the shrinkage and surface wrinkling of Royal Gala apple parenchyma cellular structure during drying. To study the cellular morphology, 3D contour maps produced by a novel 3D image and surface analysis tool, “Nanovea Expert 3D” were used. ImageJ software was used to quantify the single cell morphological characteristics. During the study, each tissue was observed continuously for the gradual morphological alterations. It was evident that there is a significant reduction of surface roughness during the drying process. In the case of individual cells, the area reduced approximately by 20% and diameter by 11%. This study provides conclusive proof that 3D contour maps and images combined with the 2D microscopic images could be a highly valuable source of information in producing data for the validation of 3D computational plant tissue drying models and simulations

Three-dimensional (3D) numerical modeling of morphogenesis in dehydrated fruits and vegetables

Plant-sourced food items, such as fruits and vegetables, are an integral part of the human diet. Fruits and vegetables, by their nature, contain up to 90% water (Jangam, 2011), which induces internal microbial activities resulting in rapid spoilage. Therefore, the removal of water from food matter makes it more resistant to spoilage (Chen and Mujumdar, 2009) since microorganisms cannot thrive in dry environments (Delong, 2006). Drying is the oldest method of economically removing moisture from food materials, resulting in traditional (as well as innovative) dried food products (Jangam, 2011). Recently, there has been a significant increase in the consumption of dehydrated food in the market (De la Fuente-Blanco et al., 2006). This necessitates to efficiently produce high quality dried food products, where a close control of moisture content of the product has to be maintained, as shown in the drying curve in Figure 17.1. It is clear that the moisture tends to remove rapidly in a given bulk food sample at the beginning of a drying process, followed by a reducing trend, due to the collapse of the food structure, as elaborated in Figure 17.2a and 17.2b. Here, a bulk scale deforming and shrinking behavior of a fresh apple sample is presented, before and after drying. As evidenced by Figures 17.1 and 17.2, the bulk food material undergoes gradual physical alterations leading to morphological changes with the removal of moisture. Depending on these variations in the bulk scale, it is evident that the cellular structure of the food material should similarly undergo consequent deformations during the process

A 3-D coupled Smoothed Particle Hydrodynamics and Coarse-Grained model to simulate drying mechanisms of small cell aggregates A 3-D coupled Smoothed Particle Hydrodynamics and Coarse-Grained model to simulate drying mechanisms of small cell aggregates

Recently, meshfree-based computational modelling approaches have become popular in modelling biological phenomena due to their superior ability to simulate large deformations, multiphase phenomena and complex physics compared to the conventional grid based methods. In this article,small plant cell aggregates were simulated using a three dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) and Coarse-Grained (CG) coupled computational approach to predict the morphological behaviour during drying. The model predictions of these cell aggregate models have been compared qualitatively and quantitatively through comparisons with experimental findings