Effect of Shell Eggs Storage on Ovomucin Extraction

Ovomucin, one of the major egg white proteins, has wide potential applications in food, functional food and nutraceutical industries due to its unique physicochemical properties and bioactivities. A new two-step method was recently developed to prepare high purity ovomucin; in this study, effect of shell egg storage on ovomucin extraction was investigated. The composition of ovomucin extracts from egg white was determined by gel filtration chromatography. Both storage temperature and time could significantly (p<0.05) affect the purity and yield of the ovomucin. After 9 weeks of storage at 4 degrees C, the content of the ovomucin in the extract decreased from 92.5% to 82.4%, and the yield of ovomucin decreased from 214 to 120 mg/100 g of egg albumen (egg white). After 5 weeks of storage at 22 degrees C, the content of ovomucin extract decreased from 92.5% to 73.0%, and the yield of ovomucin decreased from 214 to 112 mg/100 g of egg albumen. Increase in egg white pH during prolonged storage leading to degradation of ovomucin is very likely responsible for the decreased extractability of ovomucin.