Effect of starch on the gel properties and protein conformation of egg white subjected to alkali‐heat treatment

Abstract

Summary The colour, texture, water‐holding capacity (WHC) and particle properties of gels were examined to assess the impact of starch (cassava, corn and sweet potato starch) on the attributes of alkali‐heat‐induced gels. The results indicated that the whiteness, hardness and WHC of egg white gels were positively affected by starches. The microstructure of the mixed gel showed increasing reticulation and holes as the starch content increased, which contributed to the stiff structure of the gel. Although the gel made with corn starch had the lowest WHC, the gel made with sweet potato starch had the highest WHC. The average size of the gel particles decreased as a result of the inhibition of starch gelatinisation. Starch causes alterations in the protein secondary structure of egg white gels, primarily causing α‐helix and β‐sheet interconversion. The stiffness of the gels was improved by increasing the quantity of β‐sheet structures. According to the electrophoresis findings, a small amount of sweet potato starch can help prevent ovalbumin from degrading, while having no impact on the ability of the protein to cross‐link.