Study On Rapid Preparation Technique Of High Quality Salted Egg Yolk

Salted egg yolk is a kind of traditional food ingredients with unique flavor,rich nutrition and particular texture.Meanwhile,salted egg yolk is convenient,instant and widely used in many delicious dishes,and it also has a wide range of market demand.In terms of the traditional process of salted egg yolk,salted egg yolk is generally obtained from the mature salted egg.However,this method leads to some problems such as unstable quality,waste of resources,long production cycle,high manufacturing costs and food insecurity,which is difficult to be industrialized.This work chose the duck egg yolk as raw material The salt addition,moisture contents and aging conditions were studied to find the influence on quality of duck egg yolk.In order to provide the basic standard for industrialization of salted egg yolk,the duck egg yolk product processes were innovated and improved.The results showed that:The results indicated that the salt content has significant influence on extraction oil rate,soluble protein content,chromatism,relaxation properties and texture characteristics of duck egg yolk.However,it did not cause breaking or polymerizing yolk protein peptide chain to produce new protein components.Furthermore,the correlation analysis showed that in different salt contents,yolk relaxation characteristics were closed to other characteristic indexes.Hot air drying characteristics were studied in different air temperatures.The drying efficiency and product quality were comprehensively considered.The optimum drying tenperature was 50 ?.Test Page model fitting the highest degree could be used to predict the moisture content of the duck eggs in the hot air drying process.The equation of the nodelis:MR = exp {[.06775-0.00279T +(1.035 x 10-5)T2]t[1.49771-0.01746T+(1.21121×10-4)T2]}.With the prolonging time of dehydration and the decrease of moisture contents,the soluble protein contents in egg yolk,oil ratio,color difference,relaxation characteristics showed regular changes,which suggested that the moisture content had a significant impact on the quality of duck egg yolk.According to SDS-PAGE test graphs,the lower moisture content might lead to changes in egg yolk protein spatial structure,but dehydration stage did not cause breaking or polymerizing of fracture of egg yolk protein peptide.The correlation analysis suggested that there was no significant correlation between the relaxation characteristic and soluble protein content of egg yolk.However,the relaxation characteristic of egg yolk had close correlation with other indexes of egg yolk.With the prolonging time of aging time,oil extraction rate,chromatism,texture characteristics,relaxation properties of egg yolk showed regular changes in aging phase,which indicated that the aging process had significant influence on the quality of duck egg yolk.The correlation analysis suggested that there was no significant correlation between the relaxation characteristic and chewiness of egg yolk.However,the relaxation characteristic of egg yolk had close correlation with other indexes of egg yolk.Using the sensory scores as evaluation index,the optimum conditions of salted egg yolk in the single factor experiments were:2.00%salt addition amount,30 min dehydration time,10 min aging time.Based on the main process conditions,the ultrasonic assisted optimization process of the optimal conditions in single factor experiments and the Box-Behnken central composite experiments were obtained:150 W ultrasonic processing power,21 ?ultrasonic treatment temperature,11 min ultrasonic treatment time.Comparing the test products and commercial products of salted egg yolk,the result indicated that the test product had almost reached the requirements of market product quality.