DISPERSED PHASE PARTICLE SIZE EFFECTS ON WATER VAPOR PERMEABILITY of WHEY PROTEIN-BEESWAX EDIBLE EMULSION FILMS

Abstract

Lipid particle size and distribution were found to significantly affect the water vapor permeability (WVP) properties of whey protein/beeswax edible emulsion films. Films oriented with the lipid-enriched side facing the high relative humidity environment during WVP testing exhibited lower WVPs. Particle size distributions were determined before and after film formation using laser light scattering and scanning electron microscopy, respectively. Decreasing mean emulsion particle diameters correlated well with linear decreases in average film WVP values. Whey protein chain crosslinkage at beeswax particle interfaces resulted in lowered WVPs as interfacial areas increased with decreasing particle diameters, providing greater opportunity for protein-beeswax interaction. Several models were applied and interaction factors were compared for films possessing different mean particle diameters.