| This work was funded by the National Key R&D Program of China(2018YFD0400300).Egg white protein is not only nutrient-rich but also has good gelling properties which has been widely used in the food industry.However,egg white protein gel will be affected by various substances in complex food systems.Furthermore,the impact of various food additives on the strength of egg white gel is not well-known,which greatly limits the application of egg white protein gels in food industry.Therefore,this research intends to explore the effect of the amount of different small molecule additives on the properties of egg white protein gels through texture analysis,determination of free thiol and total sulfhydryl content,analysis of the water holding capacity changes,surface zeta potential and turbidity changes.The purpose of this study is to analyze the regulatory effect of small molecule additives on the structure of egg white protein gels,to provide a theoretical basis for detecting changes in the properties of egg white protein gels in hybrid food processing systems,and to provide new idea for the application of egg white proteins in jelly product.The main contents and conclusions of the present study are as follows:(1)The effect of small-molecule salt additives on the gel properties of egg white protein.The hardness,viscosity,cohesiveness and adhesion of egg white gel showed a downward trend with the increase of the amount of potassium chloride.Correspondingly,the content of free thiol and total thiol increased.However,the water holding capacity,surface zeta potential and the stability of the systems decreased.The hardness,chewability,viscosity,cohesion,content of free thiol and total thiol of egg white protein gel all showed an upward trend when the amount of sodium citrate was 0.01%.As the amount of sodium citrate continued to increase,the hardness of egg white protein gel showed a downward trend,and it was reduced to a minimum when the amount of sodium citrate was 0.3%.As the amount of sodium citrate continued to increase,the hardness of the sample increased first and then decreased.The study found that the addition of 1% zinc gluconate can lead to a dramatic decrease in the hardness,elasticity,chewing and gluing properties of the egg white protein gel system.This may be obviously related to the reduction of free thiol and total thiol content in the system,and it also leads to a decrease in the water holding capacity and stability of the system.(2)The effect of small-molecule carbohydrate additives on the gel properties of egg white protein.The present studies have found that the addition of 0.1% galactose can lead to a decrease in egg white protein gel hardness,chewability,stickiness and stickiness.The effect of galactose addition in the range of 0.1-4% on the texture properties of egg white protein gel was consistent.After galactose was added,the water holding capacity and stability of the egg white protein gel system did not change significantly.When fructose was added at 0.1%,the hardness,cohesiveness and cohesiveness of the egg white protein gel reached the maximum.At this time,the system had the lowest water holding capacity and the highest total thiol content,and the addition of fructose did not affect the egg white protein gel system.Stability.After the addition of lactose,the hardness,elasticity,viscosity,adhesiveness,free thiol and total thiol content of the egg white protein gel system decreased.When the lactose was added at 4%,the system’s texture characteristics and water holding capacity reached the minimum The addition of lactose had no significant effect on the charging performance of the system.(3)The effect of small-molecule acidulant additives on the gel properties of egg white protein.The study found that with the increase of the amount of tartaric acid,the hardness,elasticity,chewiness,stickiness and adhesiveness of the egg white protein gel decreased,the content of free thiol and total thiol in the system increased significantly,and the water holding capacity decreased obviously.Correspondingly,the stability of the system has gradually decreased.With the addition of citric acid,the hardness,elasticity,chewability,gluing and stability of egg white protein gel system showed a downward trend,and the content of free thiol and total thiol increased.When the added amount exceeds 0.1%,the water holding capacity of the system decreases significantly.With the increase of the amount of malic acid,the hardness,elasticity,chewiness and adhesiveness of the egg white protein gel system decreased.The content of free thiol and total thiol in the system increased significantly,the water holding capacity decreased significantly,and the stability of the system weakened.(4)The application of egg white protein in jelly.Based on the previous research,this study screened the ratio of the rubber powder and the added amount,and the amount of potassium chloride and citric acid to obtain a new egg white jelly formula: the ratio of carrageenan to konjac gum is 4: 6 The amount of compound rubber is 0.6 g/100 mL,the amount of potassium chloride is 0.02%,and the amount of citric acid is 0.02%. |
