Application of Meshfree Methods to Numerically Simulate Microscale Deformations of Different Plant Food Materials during Drying

9 10 Plant food materials have a very high demand in the consumer market and therefore, improved food products 11 and efficient processing techniques are concurrently being researched in food engineering. In this context, 12 numerical modelling and simulation techniques have a very high potential to reveal fundamentals of the 13 underlying mechanisms involved. However, numerical modelling of plant food materials during drying becomes 14 quite challenging, mainly due to the complexity of the multiphase microstructure of the material, which 15 undergoes excessive deformations during drying. In this regard, conventional grid-based modelling techniques 16 have particularly limited applicability due to their inflexible grid-based fundamental limitations. As a result 17 meshfree methods have recently been developed which offer a more adaptable approach to problem domains of 18 this nature, due to the fundamental grid-free advantages. In this work, a previously developed meshfree based 19 two-dimensional plant tissue model is used for a comparative study of microscale morphological changes of 20 several food materials during drying. The model involves Smoothed Particle Hydrodynamics (SPH) and 21 Discrete Element Method (DEM) to represent fluid and solid phases of the cellular structure. Simulation are 22 conducted on apple, potato, carrot and grape tissues and the results are qualitatively and quantitatively compared 23 and related with experimental findings obtained from the literature. The study revealed that cellular 24 deformations are highly sensitive to cell dimensions, cell wall physical and mechanical properties, middle 25 lamella properties and turgor pressure. In particular, the meshfree model is well capable of simulating critically 26 dried tissues at lower moisture content and turgor pressure, which lead to cell wall wrinkling. The findings 27 further highlighted the potential applicability of the meshfree approach to model large deformations of the plant 28 tissue microstructure during drying, providing a distinct advantage over the state of the art grid-based 29 microscale drying models. 30 31 32 33