Impacts of desugarization and drying methods on physicochemical and functional properties of duck albumen powder

Desugarization of duck albumen using glucose oxidase/catalase was optimized before drying. Optimum condition for desugarization using response surface methodology was as follows: glucose oxidase 31.24 units and catalase 781 units/mL albumen and incubation time of 6.55 h at 30 °C. Foaming capacity (FC) and foam stability (FS) were enhanced, while the solubility decreased after desugarization. This coincided with the increase in surface hydrophobicity (p < 0.05). Higher trypsin inhibitory activity was found in freeze-dried albumen powder than spray-dried counterpart. Trypsin inhibitory activity was continuously decreased as the inlet temperature for spray-drying increased (p < 0.05). Desugarization could increase FC and FS, but slightly decreased solubility of powders. No marked differences in protein patterns were observed in all the powders, regardless of desugarization and drying methods. L* of albumen powder decreased but ΔE, a*-, b*-values and browning index increased as spray-drying temperatures increased (p < 0.05). Therefore, prior desugarization could lower browning and increased foaming property of duck albumen, particularly when spray-dried with inlet temperature of 160 °C.