Epigallocatechin-3-gallate (EGCG) can improve functional properties of β-Lactoglobulin (βLg) by conjugation. The effects of ultrasound, a useful tool in improving the conjugation efficiency, on the various functional properties of βLg-EGCG conjugates were investigated in this study. Results revealed βLg-EGCG conjugates transformed from cross-linked state to fragments of various forms with ultrasound treatment with increased of binding affinity. Meanwhile, ultrasound increased secondary structural changes in βLg in the conjugated state. Functionally, ultrasound decreased the immunoglobulin E (IgE) combing capacity of βLg and enhanced its antioxidant properties by promoting the interaction between EGCG and βLg. Moreover, ultrasound induced an increase in hydrodynamic diameter and lowered the absolute zeta potential of βLg-EGCG conjugates, resulting in an increase in digestibility, as well as foaming and emulsification abilities, while, a decrease in thermal stability. The results provide valuable information for obtaining βLg with better functional properties for industrial production by ultrasoundassisted covalent binding of EGCG with βLg.

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Glutelin is a potential allergen that can cause allergies, celiac disease, and diabetes in infants and may even lead to autoimmune diseases in infants under 4 months of age. Given the critical role of glutelin, there exists a need for clear and standardised methods for their detection in infant formulas for special medical purposes (IFSMPs). The aim of this study was to develop an accurate and effective HPLC method for the identification of glutelin in IFSMPs. The heat-stable subunit was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis after subjecting glutelin to various heat-treatment processes. To validate the HPLC method, the different food matrices present in IFSMPs were simulated by mixing rice glutelin with milk protein concentrate (MPC), soy protein isolate (SPI), and both MPC and SPI in various ratios. The results revealed that the limit of detection (LOD) for glutelin solution was 9.7 lgÁmL À1 and the coefficient of determination (R 2 ) was 0.9909. Meanwhile, the LOD of glutelin in the food matrices ranged from 10 to 50 mgÁg À1 , and R 2 varied from 0.9802 to 0.9983. The HPLC method developed in this study displays superior detection results compared with existing methods, shortens the total detection time, and allows for more rapid and accurate identification of glutelin in IFSMPs. The developed method is expected to provide a theoretical basis for the quality control and evaluation of IFSMPs.