Analysis of Packaging Properties of Composite Antibacterial Films by Response Surface Model

Abstract

Four factors with three level Box-Behnken response surface design was employed to investigate the influence of whey protein isolate, sodium caseinate, glycerol and potassium sorbate concentrations in antibacterial films on mechanical properties, optical properties and water solubility. Analysis of variance and regression coefficients of models for responses showed that quadratic models were significant to predict tensile strength, light transmittance, haze and water solubility of the films, whereas elongation at break could be fitted by linear models. Among all the film-forming components, glycerol and sodium caseinate were important factors to affect these packaging properties. Sodium caseinate and glycerol contributed to increasing the elongation at break and light transmittance. With the addition of glycerol, tensile strength decreased, while sodium caseinate increased tensile strength and water solubility of films and decreased haze. Whey protein isolate=6.84g, sodium caseinate=5.11g, glycerol=35.00% and potassium sorbate=1.50g in 200ml film-forming solution would yield the film with tensile strength=9.45MPa, elongation at break=49.44%, light transmittance=65.61%, haze=15.13% and water solubility =56.02% through the optimization study.