Modified Of Subcritical Water On Egg White Protein In And Preparation Of High Foamability Protein Powder

In this study, white egg protein was modified by subcritical water and its physicochemical properties were studied. The results showed that the foam property,emulsion property and browning degree increased. However, pH, kinematic viscosity descended and modified white egg protein exhibited poorer foam stability. So,different concentrations of fish scales gelatin was added to modified white egg protein solution. Foam property of protein solution was checked through Foamscan.Protein powder, possessed better foam performance and foam stability, was produced to improve competition of protein powder in the market.The results were as follows:(1)White egg protein was dealed with different subcritical water temperature and time, results indicated that: with the extension time and temperature of subcritical water treatment, the pH and kinematic viscosity reduced gradually, the degree of Browning increased gradually. The foamability and emulsibility increased remarkably,160℃ 60 min got the maximum, there were 870% and 440% improved than untreated samples, respectively. The second was 140 ℃ 60 min, there were 820% and 340%improved than untreated samples, respectively.(2)White egg protein modified by subcritical water showed poorer foam stability,however, added fish scales gelatin was benefit to overcome this trait. Compared with other treatment factors, white egg protein was treated under 140 oC for 60 min by subcritical water exhibited better foam property, emulsion property and color et al. So we added different concentrations of fish scales gelatin to modified white egg protein and foam property of mixture protein solution was detected by Foamscan. The results indicated that after modified by subcritical water, the foamability of egg white protein,make small and dense foam, deformation burst at a short time, the maximum liquid carrying of foam increases. With the added of gelatin, the foam drainage reduced, the stability of foam improved, the bubble radius become shrinking and uniform. So it can effectively improve the stability and foam inhomogenous defects by add a certain amount of fish gelatin.(3)Foam property was influenced by many factors, research results indicated thatwhite egg protein modified by subcritical water showed higher surface tension, lower surface viscoelasticity, the content of free sulfhydryl, surface hydrophobicity,endogenous fluorescence and kinematic viscosity. With the added of gelatin, the surface tension reduced, the surface viscoelasticity, surface hydrophobicity, free sulfhydryl content, kinematic viscosity increased. So we can conclued that add a certain amount of fish gelatin can effectively reduce the surface tension, improve the surface hydrophobicity, increase free sulfhydryl content, increase in surface viscosity which was benefit to the improvement of the foam stability.