Preparation And Properties Of Composites Based On Whey Protein Concentrate/Wheat Crosslinked Starch Edible Films And Kraft Paper

In this research,whey protein concentrate?WPC?and wheat crosslinked starch?WCS?were used as substrates to prepare WPC/WCS composite films.The surface of WPC/WCS composite films were modified by low temperature plasma,and the effect of treating power and treating time on film performance was studied.The films and kraft paper were compounded by laminating process to obtain composites.The effects of the amount of adhesive,the laminating temperature,laminating times and DBD plasma modification on the properties of the composite material were investigated.The main contents and conclusions are as follows:?1?Preparation and properties of whey protein concentrate/wheat cross-linked starch composite filmSingle-factor tests were conducted to study the WPC concentration,WCS concentration and glycerol?Gly?addition to WPC/WCS edible film tensile strength?TS?,elongation at break?EB?,water vapor permeability?WVP?and oxygen permeability?OP?.The performance of the composite films was evaluated by a combination of principal component analysis and comprehensive rating of membership.The Box-Behnken response surface optimization test was used to determine the optimum WPC/WCS composite films preparation.The optimum process conditions were as follows:WPC concentration 5.3g/100mL,WCS concentration3.9 g/100mL,Gly additive content 48.0%?w/w?,and TS,EB,WVP,OP were4.66MPa,77.43%,2.18×10^-12g·cm^-1·s^-1·Pa^-1and1.97×10^-5cm³·m^-2·d^-1·Pa^-1respectively.?2?Effects on properties of WPC/WCS edible films by low temperature plasmaThe composite films was modified by dielectric barrier discharge?DBD?to generate low-temperature plasma,and the effect of treating power and modification time on films performance was studied.The structures of the films were characterized by atomic force microscopy?AFM?,X-ray photoelectron spectroscopy?XPS?,Fourier transform infrared spectroscopy?FTIR?and X-ray diffraction?XRD?.The results show that the DBD plasma modified composite film increases the mechanical properties?TS?,barrier properties and thermal stability of the composite f ilm.When the processing parameters are 400W-60s,the WPC/WCS film has the best overall performance;The surface modification significantly increased the roughness of the film surface and O/C atomic ratio and-OH content on the film surface,but the plasma modification had no significant effect on the crystal structure.?3?Preparation and properties of composites based on WPC/WCS films and kraft paperThe composite film and kraft paper were compounded bylaminating method.The effects of adhesive dosage,laminating temperature,laminating times and plasma modification conditions on the properties of composites were investigated.Finally,the optimal DBD plasma process parameters are:processing power 400W,processing time 60s,the best parameters of the composite material bonding process are:binder dosage 5mL/100cm²,laminating temperature 180°C,laminating times 2 times.The properties of the composites are as follows:TS=17.75 MPa,EB=21.06%,WVP=1.06×10^-12 g·cm^-1·s^-1·Pa^-1,OP=0.85×10^-55 cm³·m^-2·d^-1·Pa^-1,peel force 2.12 N.