The effect of CaCl2 on water migration, rheological properties, aggregation behavior and protein structure in rapidly salted separated egg yolk plasma and granules

This research investigated the effects of CaCl₂ on the aggregation behavior and protein structure of egg yolk plasma and granules after fast salting. The addition of CaCl₂ to the salt solution decreased T₂₃, D [4,3] and the absolute value of the zeta potential by 6.71%, 3.66%, and 3.15%, respectively, while increasing T₂₂ by 15.85% in egg yolk plasma. Moreover, adding CaCl₂ also increased the apparent viscosity and G' value of egg yolk plasma. On the other hand, the addition of CaCl₂ decreased the T₂₂, T₂₃, D [4,3], and absolute value of the zeta potential of egg yolk granules by 56.53%, 6.71%, 6.02%, and 34.27%, respectively. Furthermore, the addition of CaCl₂ increased the number of β-turns by 51.22%, whereas it decreased the number of β-sheets by 26.55% in egg yolk plasma protein. The α-helices, β-turns, and β-sheets of egg yolk granule protein decreased by 6.58%, 3.58%, and 6.96%, respectively. Additionally, the addition of CaCl₂ can increase the degree of λ_max redshift in egg yolk plasma and decrease the degree of λ_max redshift in egg yolk granules. Overall, the addition of CaCl₂ can change the aggregation mode of proteins in egg yolk plasma and granules, improving the quality of salted egg yolk products.