Microwave and ultrasound-assisted pectin treatment: A novel method to boost liquid egg white's foaming and baking efficiency

In combined processing modification, two or more modification procedures are integrated to improve food processing and efficiency. This study investigated the foaming characteristics and baking efficiency of liquid egg white (LEW) under the synergistic impacts of ultrasound (US) and microwave (MW) treatments, both with and without pectin. These energy-efficient technologies were chosen because of their suitability for improving the foaming characteristics of LEW. Using these emerging approaches, the results demonstrated that denaturation temperature significantly ( P < 0.05) increased from 95.3 °C to 107.3 °C and enthalpy first decreased then increased following MW treatments. The apparent viscosity, zeta potential, and surface hydrophobicity observed in M300-U-P imply enhanced molecular interactions and colloidal stability. The FTIR indicated that electrostatic interactions and hydrogen bonding might play a role in the generation of egg white proteins-pectin conjugates. The CD spectra demonstrated changes in secondary structure, transferring β-sheet and β-turn contents to α-helices and random coils. The extent of Maillard reaction was assessed by degree of glycation and significantly increased ( P < 0.05) with MW treatments and pectin. The foaming capacity of M300-U-P (263 ± 3.34%) was significantly ( P < 0.05) enhanced by 24.64% compared to U (211 ± 3.46%). All samples showed significantly higher foam stability than U (26.72 ± 0.79%), with M300-U-P achieving the highest stability (88.18 ± 0.87%). With the integration of these energy-efficient technologies, we aim to provide practical solutions that improve LEW's foaming properties. Angel cakes prepared by these treated LEW exhibit enhanced volume and textural characteristics.