Study On The Interaction Between Ovalbumin And Xanthan Gum And The Stabilization Of Its Emulsion

Ovalbumin(OVA)is the main protein of egg white protein.It provides high-quality amino acids to human body,and has good foaming and gelling properties.However,the emulsifying property of OVA is not ideal.The aim of this paper was to improve the emulsifying property of OVA,and investigate the interaction between OVA and xanthan gum(XG).Then,the effects of environmental factors(such as pH,ionic strength)on emulsion stability of OVA-XG stabilized emulsion were in-depth discussed.Finally,and the application of OVA-XG complex as a fat substitute in mayonnaise was also investigated.This paper focused on improving the emulsifying property of OVA and expanded its application in foods.The related results were as following:Firstly,we explored the interaction between OVA and XG under different pH conditions,as well as the influence of XG concentration and pH on the particle size,zeta potential,microstructure and rheological properties of OVA stabilized emulsion.The results showed that the interaction between OVA and XG could be deduced from the results of turbidity,ultraviolet absorption spectrum and fluorescence spectrum.With the increasing concentration of XG(0%-0.4% wt),the particle size of the OVA-XG stabilized emulsion gradually decreased.The microstructure analysis showed that the oil droplets constantly decreased,and the zeta potential showed a decreased trend.In addition,there were an improved the storage stability of the emulsion and significantly increased apparent viscosity,thereby improving the stability of the emulsion.These results exhibited that the changes of pH and XG concentration had a great impact on the stability of the emulsion.Then,the effects of ionic strengths on the emulsion stability and the interaction between OVA and XG were studied.The interaction between OVA and XG could be concluded from the results of turbidity,ultraviolet spectroscopy,fluorescence spectra and interfacial tension,which showed that sodium chloride affected the solution performance formed by OVA-XG.Large oil droplets could be seen in an OVA-stabilized emulsion,indicating that the emulsion stability was poor.A small amount of salt ions reduced the viscosity and the interaction between the droplets of the emulsion.With the increasing concentration of Na Cl,the oil droplets gradually became smaller,and the zeta-potential of the emulsion gradually reduced,and the particle size gradually decreased,which represented that a more stable emulsion was formed.In addition,the creaming index showed that the storage stability of the emulsion was improved.Finally,we studied the potential of OVA-XG complex as a fat substitute,and investigated the consequence of replacing partial fat in mayonnaise.In order to better analyze whether the fat substitute could simulate the taste and state of full-fat mayonnaise,the texture,color,rheology and stability of low-fat mayonnaise were tested.The results showed that there was little difference between full-fat mayonnaise and mayonnaise with a replacement rate of 10%.There were similar results in texture,color and rheological property between full-fat mayonnaise and mayonnaise with a replacement rate of 10%.Moreover,the results of centrifugal stability,thermal stability and low-temperature stability experiments showed that the stability of mayonnaise with a replacement rate of 10% was closer to full-fat mayonnaise,indicating that the OVA-XG complex could successfully replace part of the fat in mayonnaise and has the potential to replace fat in sauce foods.