Denatured pre-treatment assisted polyphenol oxidase-catalyzed cross-linking: effects on the cross-linking potential, structure, allergenicity and functional properties of OVA

To evaluate the impacts of denatured pre-treatments (heating and denaturants) on cross-linking and the combined effect of pre-treatment and cross-linking on the structure, allergenicity and functional properties of OVA, OVA was pre-treated in different ways and then cross-linked. Results showed that the cross-linking reaction was obviously promoted with heating at 100 degrees C for 5 min or 0.5% of SDS as the pretreatment. Due to the coordinated process of pre-treatments and cross-linking, the secondary structure was changed and the gastrointestinal digestion of OVA was promoted. Meanwhile, the emulsifying properties, foaming properties, and antioxidant properties of OVA were remarkably improved. Furthermore, the IgG and IgE binding capacities of OVA, as well as the OVA-induced degranulation capacity of KU812 were all significantly decreased. However, upon comparing the cross-linking assisted by two different pre-treatments, it was seen that heating at 100 degrees C for 5 min was better than being treated with 0.5% of SDS in reducing the potential allergenicity of OVA. Therefore, we concluded that heat denaturation (at 100 degrees C for 5 min) assisted enzymatic cross-linking may provide a new cross-linking method to develop hypoallergenic foods with good functional properties.