EVALUATION OF DRYING METHODS AND STORAGE STABILITY OF PROTEIN POWDER FROM SALTED EGG WHITES

Abstract

This study compared the effects of convective hot air drying and freeze-drying on the quality and storage durability of protein powders made from salted egg whites. The results showed that freeze-drying produced higher protein concentrations (56.43%) and powder recovery efficiency (18.43%) than convection drying, which produced a 50.58% protein yield and a 15.57% recovery rate. Nonetheless, convection drying outperformed freeze-drying in terms of solubility (11.13% versus 3.10%) and water absorption capability (2.91% versus 2.62%), all while requiring a significantly shorter processing time of 2.5 hours compared to 15 hours for freeze-drying. Over a 20 days storage period, powders treated to convection drying showed a greater increase in moisture content (0.72% increase) and water activity than their freeze-dried counterparts. Furthermore, while both drying processes resulted in lower whiteness levels, freeze-dried powders had better color stability. After a thorough study of quality features, processing efficiency, and storage longevity, convection hot air drying emerged as the preferred method for producing high-grade protein powder from salted egg whites. This strategy finds the right mix between ensuring product excellence and remaining costeffective, making it ideal for large-scale industrial procedures.