DRYING KINETICS, FUNCTIONAL PROPERTIES AND QUALITY ATTRIBUTES OF SOLAR DRIED TABLE EGGS

M.A. Kenawi, M.M. Zaghloul, M. Abd El-Hameed Sanaa

Abstract
    Drying kinetics, functional properties and quality attributes of (whole egg, egg white and egg yolk) were investigatedby using a mixed-mode forced convection solar dryer .The results showed that, the moisture content decreased continuously with drying time. The drying rates were higher at the beginning, then decreased later with decreasing moisture content and increasing drying time. The drying time required to reduce the moisture contents from the initial moisture contents of 73.48, 88.21 and 50.37% to final moisture contents of 2.74, 2.13 and 2.07% was 4, 3 and 5 hours for the whole egg, egg white and egg yolk, respectively. The results also showed a slight decrease in protein, fat and ash contents. On the other hand, there was no remarkable changes observed in the pH values for the dried samples compared with the fresh ones. The quality attributes of solar dried eggs were as good as that of the fresh ones. Solar drying revealed optimum color values and good functional properties. In the light of the obtained results, it could be concluded that solar drying had no remarkable changes on either nutritious qualities or functional properties for the final products. Therefore, it can be used to produce whole egg, egg white and egg yolk in powder forms without adversely affecting their quality attributes, nutritional and functional properties.

Key words: Table eggs, solar drying, functional properties, quality attributes