| In recent years,the liquid egg is widely used in the catering industry and food industry because it is more hygienic and convenient,which has become the development trend of the egg industry.However,due to the high-pressure homogenization and pasteurization in the process of liquid egg production,these operations often destroy the processing properties of liquid eggs,resulting in poor processing properties.Therefore,how to produce stable and excellent liquid egg products is a new problem facing the food industry in China.In this thesis,the effects of 12 kinds of salts on the tertiary structure,physicochemical properties and processing properties of liquid whole egg were studied,and the salts which could effectively improve the processing properties of liquid whole egg were screened out.The effects of the above salts on the processing properties of liquid whole egg were further studied under the conditions of high pressure homogenization,pasteurization,and combined high pressure homogenization and pasteurization.Finally,the factory design of the new type of liquid whole egg with good processing characteristics was designed.The main contents,methods and conclusions of this thesis were as follows:(1)Different concentrations of 12 kinds of salts,including sodium chloride,potassium chloride,magnesium chloride,sodium bicarbonate,sodium citrate,Ddifferent ascorbic acid sodium,disodium hydrogen phosphate,sodium pyrophosphate,sodium hexametaphosphate,L-calcium lactate,zinc lactate and sodium ethylenediamine tetraacetic acid iron(Na Fe EDTA),were added into the liquid whole egg,respectively.The tertiary structures of salted liquid whole egg were investigated by UV-Vis spectroscopy,exogenous fluorescence spectroscopy and endogenous fluorescence spectroscopy,respectively.And the physicochemical properties including p H,chromaticity and turbidity and particle size distribution of salted liquid whole egg was determined.The results showed that the effects of salts on the tertiary structure of liquid whole egg proteins were different,and the proteins mostly showed two states of stretching or contracting.Among them,Na Fe EDTA had the greatest influence on the tertiary structure of the egg proteins,which could significantly reduce the internal and external fluorescence intensity of protein,and significantly improve the maximum UV absorption peak.Zinc lactate,sodium citrate,sodium D-isoascorbate and three kinds of phosphates(disodium hydrogen phosphate,sodium pyrophosphate and sodium hexametaphosphate)had relatively little effect on the tertiary structure of the proteins.Sodium chloride,L-calcium lactate,zinc lactate,and Fe Na EDTA could significantly decrease the p H of liquid whole egg,while phosphates,sodium citrate and sodium bicarbonate could significantly increase the p H.Most of the salts decreased the lightness,but increased the yellowness and redness of liquid whole egg.The addition of sodium chloride and potassium chloride could significantly reduce the turbidity,while zinc lactate could significantly increase the turbidity of liquid whole egg.In addition,the average particle size of liquid whole egg was increased by all the 12 salts,the proportion of particle size in the range of 10 ?m to 1000 ?m was increased.(2)The effects of 12 kinds of salts(ditto)on the protein solubility and processing properties(including foaming,emulsifying and gelling properties)of liquid whole egg were investigated.The results showed that the suitable salts could improve the protein solubility and part of the processing properties of the liquid whole egg,but most of the salts could decrease the other processing properties at the same time.After comprehensive analysis,the salts with better effect to improve the processing properties of liquid whole egg were selected,including 0.2 M(1.17%,m/v)and 1.6 M(9.35%,m/v)sodium chloride,40 m M(0.81%,m/v)magnesium chloride,6 m M(0.15%,m/v)zinc lactate and 9 m M(0.24%,m/v)sodium pyrophosphate.9 m M sodium pyrophosphate,0.2 M and 1.6 M sodium chloride significantly improved the foaming and gelling properties of the liquid whole egg,40 m M magnesium chloride and 6 m M zinc lactate significantly improved the emulsifying properties of the liquid whole egg.(3)The effects of the selected salts on the processing properties of the liquid whole egg were investigated under different conditions of high-pressure homogenization(4MPa/45 s,8MPa/45 s and 16MPa/45s)and pasteurization(66?/3min,66?/3.5min and 66?/4min).After determining the optimal homogenization and pasteurization conditions of different salted liquid whole egg,the effects of salts on the processing properties of liquid whole egg under the conditions of combined high-pressure homogenization and pasteurization were investigated.The results showed that homogenized at 4MPa/45 s and pasteurized at 66?/4min with 0.2 M sodium chloride had the best effect,which showed that the foaming ability and gel hardness were increased by 19.30% and 25.26%,respectively.Homogenized at 16MPa/45 s and pasteurized at 66?/4min with 40 m M magnesium chloride,the emulsifying ability and emulsifying stability of liquid whole egg were improved by 12.24% and 35.29%,respectively.Homogenized at 16MPa/45 s and pasteurized at 66?/3.5min with 6 m M zinc lactate,the emulsifying ability and emulsifying stability were improved by 5.39%and 300.96%,respectively.Homogenized at 8MPa/45 s and pasteurized at 66?/4min with 9 m M sodium pyrophosphate,the foaming ability,emulsifying ability and gel hardness were increased by 10.54%,10.82% and 27.47%,respectively.And the corresponding processing properties of the liquid whole egg added with salts were all better than that of the control group,showing great application potential.(4)The factory was designed for the new type of liquid egg product with an annual output of 3000 tons,mainly including the general plane design,workshop design,process design,equipment selection and other aspects of the factory,and the plane design of the factory,the plane design of the production workshop and the flow chart of the equipment were drawn.Finally,the annual sales and annual net profit of the new type of liquid whole egg with an annual output of 3000 tons were calculated,which would be 390 million yuan and 2680796 million yuan,respectively. |
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