Shrinkage during vacuum cooling of porous foods: Conjugate mechanistic modelling and experimental validation

Abstract

A conjugate modelling of momentum, heat and mass transport, and structural deformation during steamed bread vacuum cooling (VC) was developed and validated with nuclear magnetic resonance/magnetic resonance imaging. The moisture variation was correlated with shrinkage and the coupled two-dimensional problem was solved using the Arbitrary Lagrangian-Eulerian method. Results revealed that the three-parameter Maxwell model accurately described the viscoelastic behaviour of the bread during VC and was superior to the linear elastic model. Additionally, the model prediction was accurate with R 2 values and maximum errors of 96.35% and 9.56% for moisture variation, and 99.65% and 13.51% for areal shrinkage, respectively. Sensitivity analysis revealed that the deformation model was more sensitive to water transport parameters than the viscoelastic model. Notably, the hydrous compressibility factor had the highest sensitivity to the deformation model. The developed model could be used for quality index evaluation to better understand and optimize the VC of porous foods, thereby improving the product's quality. • Shrinkage during vacuum cooling (VC) of steamed bread was modelled. • Conjugate transport and deformation modelling during VC was developed. • Steamed bread was accurately represented using linear viscoelastic model. • The model prediction was accurate for moisture variation and shrinkage. • Water transport parameters strongly influenced structural deformation.