| Traditional egg products such as preserved eggs and salted eggs are deeply loved by consumers.The main processing technology is pickling and penetration.However,during the curing process,due to the barrier effect of the shell and the shell membrane,the penetration of the substance and the content of the eggs Changes will be affected accordingly,resulting in low curing efficiency and poor product quality.In order to solve this problem and improve the production efficiency and food quality of shell egg products,at the same time,in order to develop the functional egg products with shells in the future using the method of pickling and penetration,this study used alkali treatment to improve the effect of pickling and penetration of shell eggs Orthogonal experiments were used to select suitable alkali treatment conditions.The three processing methods of normal pressure,high pressure and pulsating pressure were compared and analyzed,the mechanism of action in the pulsating pressure curing process was explored,and the superiority of the pulsating pressure curing technology was found.Choosing the method of alkali treatment combined with pulsating pressure curing,on the basis of single-factor experiment,initially explored the condition parameters of the process,and obtained the best curing conditions.Choosing the processing method of pulsating pressure alkali treatment,Polygonum multiflorum as an infiltration component,analyze the feasibility of new egg products.The main research content and results are as follows:1. Use different concentrations of alkaline solution to treat fresh eggs for different times,and then use high temperature heating instead of curing after curing.It was found that after being immersed in 6%alkaline solution for 4 days,the eggshell alkalinity reached the highest,136.01±1.10 mg/100g,and the water content was the lowest,85.06±0.28%.With the increase of alkaline solution concentration,the processing time increased,and the elasticity and viscosity of egg white decreased,and the viscosity of egg white rebounded after the fourth day of treatment with 6%alkaline solution concentration.After alkali treatment,the number of eggshell stomata exposure increased,the penetration efficiency increased,the color of protein was significantly higher than that of untreated,and the color was proportional to the treatment time.The highest after the fourth day was 17.93±0.88,which was 2.51 times that of untreated.The protein gel after alkali treatment has unique senses,reduced hardness and elasticity,and improved cohesion,up to 0.983±0.004,which is 1.14 times that of the untreated group.It has a unique soft and dense mouthfeel.After comprehensive judgment,the final choice is 4%Na OH soaked fresh eggs for 1 days as pre-treatment conditions.2. Choose three processing methods: normal pressure,high pressure and pulsating pressure,treat the eggs under the conditions of no salt and salt,and compare and analyze the egg white salt content,surface hydrophobicity,primary and secondary structure changes and egg white protein Gel properties.It was found that the salt content of egg white after pickling by pulsating pressure was the highest,reaching 0.09±0.01 g/g,which was 2.10±0.23 times that of untreated;the combined effect of pressure,temperature and salt increased the surface hydrophobicity,and the salt-containing normal pressure group The highest was 791.98±9.33.Among them,after the pulse pressure curing,the amide II band wavelength redshifted to 1520 cm-1,the content of?-helix and random curl decreased,and the content of?-fold increased;Na Cl would reduce the gelability of egg white,compared with high pressure treatment,pulsation The pressure can relatively improve the adverse effects of Na Cl;the elasticity of the egg white gel after pulsating pressure curing is increased to 1.02±0.01,the T21 relaxation time is reduced to 25.79±0.01 ms,the centrifugal loss is 6.49±0.96%,and the water holding capacity Increase,the microstructure has been greatly improved.3. After immersing fresh eggs in 4%Na OH for 1 days,and then pickling them with pulsating pressure under different conditions,in the process of intermittent pressurization,the alkalinity of egg whites drops,and the lowest is 35±0.2 mg/100g at high pressure treatment time.The salt content increased and the penetration rate increased,reaching a maximum of 0.102±0.006 g/g,which was 1.46 times that of the normal pressure group.Compared with the normal pressure treatment group,pulsating pressure processing has no obvious effect on the secondary structure of egg white protein,and the protein color should be more uniform and the penetration effect is better.When the pulsating pressure high pressure time was 25 min,the?E value of egg white protein was the highest,and the outer layer protein and inner layer protein were 14.81±0.76 and 14.43±1.04,respectively.The greater the difference between the duration of high pressure and the duration of normal pressure,the higher the impact on the egg white protein gel.The combination of electron microscopy and observation shows that the gel structure is best at 35 minutes,followed by25 minutes,and the best is selected according to the penetration effect.The process conditions are 45?,high pressure 180 k Pa for 25 min,low pressure 0.1 k Pa for 5 min.4. Choose 4%Na OH,1.5%Na Cl and Polygonum multiflorum cooking liquor as the pickling liquid,and process for five days under the conditions of pulsating pressure at 1k Pa for 5 min at normal pressure and 25 min at high pressure for 180 k Pa.Comparative analysis of the color,salt content and alkalinity of egg white,and the color,texture,water distribution and water retention of egg white gel,found that the color of egg white deepens with the increase of pulse pressure time,and the?L value is the fourth Day reached the highest value,5.47 times that of the untreated group,and the?a value reached the highest on the 5th day,which was 7.42 times that of the untreated group;the alkali and salt content in the egg white reached the highest value on the 5th day;egg white gel The?a value reached the highest on the 5th day,which was 3.89 times that of the untreated group;the hardness of the egg white gel reached the maximum on the 2nd day,but on the 3rd day the hardness of the egg white gel was broken down,except for this In addition,the elasticity and cohesion of the egg white gel treated with pulsating alkali pressure were significantly higher than that of the untreated group on day 0?p<0.05?;after pulsating alkali pressure treatment,the mobility of bound water was significantly reduced?p<0.05?,the combination of difficult-to-flow water and protein molecules becomes tighter during 0-2days of pulsating alkali treatment,but after the second day,the combination of difficult-to-flow water and protein molecules becomes loose again;in pulsating alkali treatment After that,the water retention of egg white gel increased greatly,the centrifugal loss on the 5th day was the lowest,and the water retention was the highest. |
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