Effects Of Transglutaminase And Spray Drying Conditions On Gelling And Emulsifying Properties Of Egg White Powder

TGase can improve the gelling and emulsifying properties of egg white powder by causing a certain cross-linking reaction of EWP.In order to improve the gelling and emulsifying properties of egg white protein,egg white protein was modified by transglutaminase(TGase),and egg white powder was produced by spray drying.The effects of TGase treatment conditions and spray drying conditions on the gelling and emulsifying properties of egg white powder were studied,and preliminary study of the effect of TGase on protein cross-linking in egg white powder,the main results are as follows:1.The optimum conditions for the effect of TGase on gel hardness and emulsifying pro-perties of egg white powderTGase can improve the gelation and emulsifying properties of egg white powder by causing a certain cross-linking reaction of EWP.The optimal conditions for the effect of TGase on the thermal gel hardness of egg white powder solution(13g egg white powder :100g water)are: pH value 7.05,enzyme acting temperature 34.89°C,enzyme acting time85.73 min,and TGase addition 3.4 U/g protein.Under this condition,the thermal gel hardness reached 800.3 ± 5.237 g,which was 53.95% higher than that of the control group.The optimal conditions for the effect of TGase on the emulsification activity of 1% egg white powder solution are : pH value 6.56,enzyme acting temperature 34.66?,enzyme acting time91.01 min,and TGase addition 3.45 U/g protein.Under this condition,the emulsification activity of egg white powder reached 0.469 ± 0.001,which was 37.58% higher than that of the control group,and the optimal conditions of the emulsion stability are: pH value 6.53,enzyme acting temperature 35.0?,and TGase addition 3.45 U/g protein(enzyme acting time90.0 min).Under this condition,the emulsification stability of egg white powder reached19.447±0.217,which was 28.70% higher than that of the control group.2.The optimum conditions for the effects of spray drying conditions on the gel hardness and emulsifying properties of egg white powderSpray drying conditions affect the morphology of the egg white powder and the denaturation of egg white protein,which in turn affects the gelling and emulsifying properties of the egg white powder.The optimal conditions for the effect of spray drying conditions onthe thermal gel hardness of egg white powder solution(13g egg white powder : 100 g water)are: inlet air temperature of 172.33?,feed rate of 26.58%(7.442 mL/min),and dilution factor of 28.44%(feed temperature 40°C).Under this condition,the thermal gel hardness reached 844.476 g.The optimum conditions for the effect of spray drying conditions on the emulsification activity of 1% egg white powder solution are: inlet air temperature was162.12°C,feed temperature was 39.31°C,feed rate was 28.99%(8.117 mL/min)(dilution factor 20%),and the emulsification activity of egg white powder reached 0.477 ± 0.0029,and the emulsion stability was 18.787 ± 0.463.3.3.Preliminary study on the influence of TGase and spray drying conditions on the gelation and emulsifying properties of egg white powderAnalysis by SDS-PAGE electrophoresis results:it can be concluded that under certain conditions,TGase can cause intramolecular and intermolecular cross-linking of some EWP,and form a relatively high molecular weight protein molecule to make protein.The structure is more compact,increasing the ability of proteins to adsorb water molecules,resulting in a significant increase in egg white gel hardness.The spray drying conditions have little effect on the cross-linking polymerization of protein.