Effect of dry heat treatment of egg white powder on its functional, nutritional and allergenic properties

- Dry heating of egg white powder increases its interfacial properties.
- Strong dry heating of egg white powder decreases protein in vitro hydrolysis.
- Dry heating of egg white powder decreases lysozyme but increases ovotransferrin antigenicity.
- Multiple factorial analysis highlights intermediate dry heating treatments as optimum.

Egg white is a key ingredient in many food products as it combines high nutritional quality with excellent functional properties. However, it is also one of the leading causes of food allergy in childhood. Dehydrated egg white is a common form of industrial egg white. To increase the functional properties, egg white powders are heated which may change protein antigenicity and susceptibility to digestion. The present work highlighted the effect of a wide range of dry heating rates (from 1 to 10 days between 60 and 90 °C) simultaneously on the interfacial properties, antigenicity and susceptibility to in vitro digestion of egg white proteins. Thanks to a powerful statistical methodology, i.e. multiple factor analysis (MFA), that enables to consider all the data in a common space, intermediate dry heating treatments (2-5 days at 70 °C or 1-2 days at 80 or 90 °C) were found to be good compromise to improve egg white functionality without enhancing too much protein resistance to digestion or protein antigenicity.