Whey protein film composition effects on potassium sorbate and natamycin diffusion

To asses the asses the ability of whey protein films to act as antimicrobial carriers, the effect of film composition on preservat diffusion was investigated. Preservative diffusion coefficients were measured at 24 °C in whey protein isolate (WPI) films with different WPI-glycerol plasticizer ratios (1:1 to 15:1), beeswax (BW) content, 0% to 40% w/w dry solids, and preservative addition of 0.3% (w/w) natamycin or 1.6% (w/w dry solids) potassium sobate. Diffusion coefficients for potassium sorbate and natamycin were in the ranges 1.09 × 10 -8 to 13.0 × 10 -11 m 2 /s and 6.16 x 10 -14 to 37.8 x 10 -14 m 2 /s, respectively, and significantly de as the WPI-glycerol ratio increased. No significant difference in sorbate diffussion was seen with the addition of BW.