Rheological properties of protein hydrolysates with gel properties from scallop (Patinopecten yessoensis) male gonads

In order to provide a foundation for comprehensive utilization of scallop ( Patinopecten yessoensis) , the rheological properties of hydrolysates from scallop ( Patinopecten yessoensis) gonad ( SMGHs) were studied. The hydrolysates were obtained from scallop male gonads ( SMGs) by using papain as a tool enzyme.The changes in molecular mass of proteins were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE) . The rheological properties of SMGHs were determined by rheometer.The effect of DNA on rheological properties of SMGHs was also investigated by incubated with DNaseⅠ.The results showed that the proteins of SMGs were significantly degraded after hydrolysis with papain at a dosage of 30000 U/g protein for 15 ¹80 min. Under various sweep models, the values of storage modulus G', loss modulus G″, viscosity η, complex viscosity η*of SMGHs were obvious higher than those of SMGs. After hydrolysis for 3 h, the initial values of G', G″ during oscillation strain scanning were up to 188.9, 17.9 Pa at oscillation strain of 1%, respectively.The value of η*was 230.9 Pa·s at frequency of 0.1 Hz.The rheological properties ( G', G″ η*) of SMGHs decreased significantly, but slightly higher than those of SMGs, by treatment with DNase Ⅰ. These results suggest that the elastic property is dominant in SMGHs exhibiting obvious shear thinning effect.Moreover, the rheological properties of SMGHs might be related to peptides and DNA molecule.