Interface Mechanics, Dynamics And Rheology Studies Of Protein Solution

Emulsion and foam stability are one of the most important properties in the protein solution system.It is closely related with the interfacial phenomenon in the layer formed by solution,including interfacial mechanics,dynamics and rheological behaviors.The interfacial layer properties are the external exhibition of molecular interaction,it is essential for the stability of protein solutions to understand the interfacial phenomenon in the layer.In this study,the body solution properties of Zein,ovotransferrin,sodium dodecyl sulfate combination of single solute,double solute,triple solute solution system were measured.And the interfacial properties of each solution system at air-water interface and oil-water interface were studied by dynamic drop analysis.And the relationship between macroscopic bubble stability and interface properties is discussed,which provided the basic data for studying emulsification and foam stability of protein solutions.The main conclusions are as follows:1.Through the study of the solution properties of each protein solution system,it can be seen that OVT systems interact with one another after SDS is added,enhancing the solubility,reducing the particle size,loosening the protein structure,and making the microenvironment around the tryptophan residue more hydrophilic.In the triple solute complex system(OZS),the combination of OVT,Zein and SDS has a competitive effect.2.The interface pressure and time curve of each protein solution system can be divided into three stages: induction period,rapid increase and slow increase.In the complex system,the presence of SDS accelerates the adsorption of the OZS complex on the interface,and the initial interface pressure of the protein solution system is smaller.On the interface of gas and water,there are interactions between different fragments and side chains of OVT and Zein on the interface to promote the adsorption of the system protein into the interface and further expand the interface.3.In the determination of the adsorption range,the protein solution system belongs to the diffusion-control adsorption.In the single-solute OVT system,the diffusion rate increases on the interface between the gas-water interface and the oil-water interface with the increase of the initial volume of the OVT,and the diffusion is driven by concentration gradient.After the addition of SDS,the structure of the OVT protein changes,and there is a competitive adsorption of OVT,SDS and OVT + SDS on the interface.After the protein solution diffuses into the air-water and oil-water interface,the permeation and rearrangement mechanisms control the adsorption kinetics.In the OZS solution system,the osmotic expansion rate and rearrangement rate of the system are increased due to the interaction between proteins of Zein and OVT.4.The interfacial expansion and rheological properties of the adsorption solution of each protein solution shows that the elastic modulus of the protein membrane on each interface of the protein solution system(Ed),the same as the adsorption time,on the gas-water interface or the oil-water interface rapidly increases and then slows down.In the OVT system alone,the Ed value is significantly decreased after adding SDS,while the interface protein structure of the OZS solution system is enhanced and the Ed value increased.The complex expansion modulus(E)of the adsorbed film increases with the increase of the interfacial pressure(?)value,and the interaction between the adsorbed layer protein molecules gets more obvious with the increase of OVT concentration.5.The foaming capacity of OVS is poor,but the foam stability is rather high.The foaming ability of SDS and Zein + SDS alone is strong,but the foam stability is weak,and the OZS system is the strongest both in the foaming ability and foam stability,mainly due to its formation of flexibility and a rigid composite adsorption layer.Therefore,the bubble can better respond to external stress,which,with the above solution system of adsorption kinetics and rheological research,is consistent.These findings indicate that the system can provide a theoretical reference for foaming agent ingredients for cosmetics,food and other industries.