Study On The Process Of Ultrasonic-assisted Pickling Salted Egg

Salted egg is a kind of traditional food with unique flavor, so there is an extensive market demand. However, due to the long cycle of the traditional pickle processing it could not satisfy the modern people consumer demand for the food safety, nutrition, and flavor. So it is necessary to improve the traditional preserve processing technology. Taken fresh duck eggs as raw materials, the ultrasonic- assisted preserve process of salted eggs was studied in this paper. The main conclusions could be summarized as follows:(1) The contrast experiment of three pickle processes of salted egg-untreated,an ultrasonic treated before curing, multiple ultrasonic treated during the curing was designed, and the effect on the curing rate and quality of salted egg was discussed. Results showed that the ultrasonic treatment promoted salt infiltration into eggs significantly, shorten the pickled time of salted eggs, and improved the taste quality of salted egg to a certain extent, which indicated that using ultrasonic technology to improve the salted eggs pickled process was feasible.(2) Central composite design of Box-Behnken was applied for the optimization of the preserve processesing parameters of salted egg by ultrasonic-assisted method. The regression equation of ultrasonic treatment times(X1), power(X2), treatment time(X3) to the salt content in egg white (Y) was obtained as follow:Y=-18.38+6.45X1+0.0015X2-0.71X3-0.36X1X3-0.00047X2X3-0.77X12-0.0056X32According to the regression equation analysis, the optimum optimization preserve processesing parameters of salted egg by ultrasonic-assisted method was obtained:when the ultrasonic times was 3, the power was 300W/kg and the time of ultrasonic was 43min, the salt content in egg white reached 5.66%.In order to control the pickling time accurately, the change law of the salt content in egg white and yolk under the optimum condition of ultrasonic-assisted processing was studied, the regression equation of the pickled time(x) to the salt content in egg white(y1) and the salt content in egg yolk(y2) were:y1=-0.00010x2+0.0051x+0.0041, y2=-0.000020x2+0.00090x+0.0020, it was easy to find out that 58.33% pickle time was saved under the optimization conditions of ultrasonic-assisted pickle process.(3) In order to improve the quality of salted egg further, after-ripening process was taken, and the variation of salt content in egg yolk and quality during the after-ripening process was studied. The results showed that the afte r-ripening treatment could significantly improve the quality of salted egg yolk. During the after-ripening process, ambient temperature was related to the variation of salt content, moisture content and oil extraction in egg yolk, however, it showed no relationship with equilibrium values. The salt content, moisture content and oil extraction in egg yolk reached equilibrium value after 30 d,25 d,15 d under 5℃,20℃,28℃ ambient temperature respectively. Quality of salted eggs was associated with ambient temperature and time, and after 20 d,30 d,10 d, the comprehensive sensory score of salted egg reached the highest under ambient temperature of 5℃,20℃,28℃ respectively.