Research on Antimicrobial Activity and Packaging Performance of Degradable Protein Films

The degradable protein film-forming materials contained 5% whey protein isolate (WPI), 2% sodium caseinate (NaCas) and 50% glycerol,which was the optimal formula obtained by uniform design method of previous work. The antimicrobial activity and packaging performance of WPI-NaCas degradable protein films were discussed by addition of nanoTiO2 at different concentrations (0,0.05,0.10,0.15,0.20g•(200ml)-1) in film-forming solution.The results showed that nanoTiO2 and protein films showed a certain degree of compatibility.Addition of nanoTiO2 could improve tensile strength and elongation at break of the protein films and decrease WVP values of the films,but decrease light transmittance,increase haze of the protein films. The degradable protein films suited for using below150°C.And,nanoTiO2 incorporated into protein films had antimicrobial activity against both E.coli and S.aureus.