Résumé
The effect of three cooling rates (rapid, intermediate and slow CR) on the moisture barrier properties and on the physical state of acetylated and high melting point hydrophobic self-supported moisture barriers has been investigated. The selected CR were representative of industrial processing conditions and the selected barrier materials of common effective GRAS substances (acetomonopalmitin, white beeswax, two commercial blends of beeswax and acetylated glycerides and a blend of palmitic/stearic acids). Variations of CR affected crystallisation kinetics, SFC in an extend depending on the fat chemical composition and degree of undercooling, crystal size and ratio of polymorphs present in the materials. It did not have major influence on the contact angles with water measured at the surface of the materials and on the mass-volume area properties of the material. The resultant effect on the macroscopic moisture barrier properties of the materials were evaluated using water vapour permeability (WVP) measurements. The CR had no significant effect on the WVP, except for one blend of acetylated fat and beeswax for which a slow CR may have favoured the healing of imperfections. The variations of WVP between all materials and CRs were mainly attributed to variation in materials polarity using multivariable analysis