Storage stability of scallop (Patinopecten yessoensis) male gonad hydrolysates/κ-carrageenan composite hydrogels embeded curcumin

The combination of scallop male gonads hydrolysates (SMGHs) and κ-carrageenan (KC) was applied for curcumin (Cur) embedment and preservation, the corresponding Cur retention rate as well as gelation and microstructural properties were investigated during storage subjected to various pH (8 and 6) and temperature (25 °C and 4 °C). SMGHs-based gels could well protect Cur from degradation during 4 °C storage, with retention rate ranging from 95% to 97% after 30 day storage. At 25 °C, Cur could still be well preserved in SMGHs-based gels under pH 6 with Cur retention rate above 90%, while pH 8 led to rapid Cur degradation to around 75%. In addition, at pH 8 and 25 °C, the gel strength of SMGHs-Cur deteriorated significantly while evidently enhanced in SMGHs/KC-Cur due to synergistic combination within SMGHs and KC in couple with dehydration effect. Moreover, the water migration and distribution of SMGHs-based Cur-loaded vehicles were relatively stable at 4 °C while revealed apparent deterioration at 25 °C during storage. Furthermore, the microstructures of SMGHs/KC-Cur gradually transformed from homogeneous network with dense and smooth pores to tattered network with large and fragmentary pores, especially at 25 °C, promoting more Cur degradation. This study demonstrated that SMGHs/KC-Cur exhibited better than SMGHs-Cur in Cur preservation, potentially performing as excellent and sustainable protein hydrolysate/polysaccharide soft materials in food and biomedical fields.