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The changes in rheological properties of egg white stored in biodegradable package were investigated by pH change, failure stress and stress relaxation curve, and compared with control without package and complex PE. Initial pH of egg white stored in biodegradable package changed from 8.39 to 9.3 after 8 day storage, showing similar trend in pH change as that of control without package. Initial 14.25 N failure stress was changed into 6.76 N in biodegradable package and 9.31 N in control. Complex PE, having a relatively low gas permeability compared to biodegradable package, showed less pH changes from 8.30 to 8.81, but a greater decrease in failure stress into 5.29 N, indicating more deteriorating effect in complex PE package. Viscoelastic constants, such as elastic constant and viscous constant, obtained from stress-relaxation curve by three element Maxwell model were not significantly different between control and biodegradable package, but eggs stored in complex PE showed greater changes during storage. Therefore, the permeability seems to be the major factors to influence the rheological properties of egg and biodegradable packaging materials showed a potential substitute package for eggs.
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