Diacylglycerol pre-emulsion prepared through ultrasound improves the gel properties of golden thread surimi

Highlights • DAG pre-emulsion with good stability was obtained by ultrasound. • DAG pre-emulsion increased whiteness of composite gels. • DAG pre-emulsion improved the gel strength and WHC of composite gels. • Composite gels containing DAG pre-emulsion formed a more compact 3D network structure.
This study determined the influence of diacylglycerol (DAG) pre-emulsion on the gel properties and microstructure of golden thread surimi gels. DAG emulsion stabilized using sodium caseinate was pre-emulsified through ultrasound. The average particle size of DAG pre-emulsion decreased from 1324.15 nm to 41.19 nm, with notable improvements in apparent viscosity and storage stability. The surimi gels with different amounts (0%, 1%, 3%, 5%, and 7% w/w) of DAG pre-emulsion were prepared under heat induction. The whiteness of the composite gels markedly increased with the incorporation of DAG pre-emulsion. The peak T22 value of immobilized water, the gel strength, and water-holding capacity increased gradually, but it slightly decreased with the addition of 7% pre-emulsion. The curve of G′ and G″ kept climbing as the concentration of pre-emulsion, and the microstructure of the gel network tended to become denser and more orderly. Principal component analysis (PCA) of electronic nose results showed that the surimi gels containing pre-emulsion could be clearly distinguished from the control group. In conclusion, the addition of 5% DAG pre-emulsion to surimi not only improved gel properties to the highest extent but also be compensated for lipid loss during the rinsing of surimi.