Intermolecular interaction in the hybrid gel of scallop (Patinopecten yessoensis) male gonad hydrolysates and /c-carrageenan

摘要

Various bond disrupting agents including NaCl, GuHCl, urea, and SDS were introduced to investigate the intermolecular interactions between scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs) and κ-carrageenan (κ-C), which were monitored by changes in rheological property, water distribution, conformation characterization and microstructure by using rheometer, low field-NMR relaxometry, Fourier transform infrared (FTIR) spectroscopy, cryo-scanning electron microscopy (cryo-SEM), and confocal laser scanning microscopy. The results showed that the bond disrupting agents deteriorated the rheological property of SMGHs/κ-C in a dose-dependent manner. Indeed, at the same concentration of 2 M, NaCl deteriorated the SMGHs/κ-C more obviously than GuHCl and urea. In addition, SMGHs/κ-C with bond disrupting agents possessed higher relaxation times including T_(21) and T_(23), indicating the migration to free water direction of bound and free water. Moreover, the FITR results showed the red-shift in water regions (amide A and B bands), amide I and Ⅱ bands, and indicated the breakdown of hydrogen bonds and electrostatic interactions, indicating a disordered structure in SMGHs/κ-C by various bond disrupting agents. Furthermore, cryo-SEM results showed the change of SMGHs/κ-C from a homogeneous network to a looser and ruptured one with larger void spaces, and indicated the disrupted and tattered microstructure of SMGHs/κ-C by various bond disrupting agents. Additionally, SMGHs/κ-C as well showed less aggregates stained by RITC by bond disrupting agents. These results suggest that electrostatic interactions would be mainly involved in the maintenance of SMGHs/κ-C gel network. This study could provide theoretical and methodological basis for hydrogel products with modified gel strength and microstructure by understanding the intermolecular interactions in gel system.