Study On Heat And Mass Transfer Characteristics And Technological Parameters Of Frozen Egg Freezing Process

As a food raw material,frozen eggs have been involved in medical treatment,baking and other industries.Optimizing the freezing process of frozen eggs and improving the guiding role of cold processing of frozen eggs are of great significance for improving the quality of frozen eggs.Frozen eggs mainly include frozen protein,frozen whole egg and frozen egg yolk.There are few researches and analyses on the freezing process of frozen eggs,and the guidance of the freezing process is not strong.Therefore,the temperature change trend of frozen egg freezing process is analyzed,and the physicochemical properties and protein denaturation degree of frozen egg freezing process are studied to provide guidance for improving the quality of frozen eggs.In this paper,the mechanism of heat and mass transfer,the growth mechanism of ice crystal,the mechanism of protein denaturation and the influencing factors of protein denaturation during the freezing of frozen eggs were analyzed.CFD software was used to simulate and establish a three-dimensional physical model of frozen eggs.The effects of different types,freezing temperature,convection heat transfer,volume and water content on the freezing process of frozen eggs were simulated and provided a reference for accurate prediction of freezing time.The effect of freezing temperature on the quality of frozen eggs was studied through the change trend of PH,conductivity and protein concentration of frozen eggs before and after freezing,so as to provide reference for improving the quality of frozen eggs.Firstly,the specific heat capacity,moisture content,thermal conductivity,density and surface heat transfer coefficient of frozen egg were determined by empirical and theoretical formulas of physical parameters,and the mechanism of protein freezing denaturation was studied and analyzed,which laid a foundation for simulation and experiment.Secondly,the freezing process of frozen eggs under different freezing conditions is simulated,and the results are as follows:the freezing rate at the same freezing temperature is from large to small:frozen egg yolk,frozen whole egg,and frozen protein.The lower the freezing temperature is,the shorter the freezing time is.The larger the convective heat transfer coefficient is,the shorter the passing time is.The larger the volume,the longer the freezing time;The lower the moisture content,the shorter the freezing time.Finally,the PH value and conductivity of frozen protein,frozen whole egg and frozen egg yolk all increased after freezing by experimental analysis at-20℃,-30℃ and-40℃.Moreover,the lower the freezing temperature,the closer the PH value and conductivity of frozen eggs are to the initial value,and the higher the total protein concentration of frozen eggs is.And at30℃,the higher the salt concentration of the frozen whole egg,the smaller the degree of protein denaturation,and the total protein concentration has a maximum value when the salt content is 5%.