Ultrasound-assisted ionic extraction modulates the structural, interfacial, and digestive properties of Protaetia...

This study compared proteins from Protaetia brevitarsis larvae (PBP) extracted using water or a salt solution, with and without ultrasonication. Water extraction combined with ultrasonication (DW-US) resulted in the highest extraction yield and protein solubility at pH 6 and above. Ultrasonication significantly increased the mean particle diameter (p < 0.05). Surface hydrophobicity, reflecting the exposure of hydrophobic groups, was highest (468.58 RFU) in salt-solution extraction with ultrasonication (NaCl-US), whereas DW-US showed the lowest value (396.10 RFU). NaCl-US exhibited superior foaming capacity (158.33%), foam stability (118.33%), and emulsion stability (83.35%), whereas DW-US did not differ significantly from water extraction without ultrasonication. However, the emulsifying capacity of NaCl-US (0.103 Abs₅₀₀) was lower than that of the other PBPs (0.206-0.214 Abs₅₀₀), possibly because of its excessive foaming capacity. NaCl-US showed the highest in vitro digestibility. Overall, ultrasonication enhanced PBP extraction in water, whereas salt-solution extraction combined with ultrasonication improved its functional properties.