Optimised condition for preparing sea cucumber ovum hydrolysate-calcium complex and its structural analysis

摘要

Summary This study aimed to determine optimum preparation conditions of sea cucumber ovum hydrolysates-cal-cium (SCOHs-Ca) complexes by Box-Behnken design and further elucidate their microstructure characteristics using Fourier transform infrared spectroscopy, scanning electron microscope, atomic force microscopy and dynamic light scattering. The predicted calcium-chelating capacity under the optimum conditions of the process variables was very close to the experimental value (53.45 ± 0.29 mg g~(-1)) determined in the batch experiment. Results demonstrated that the calcium bind to the SCOHs to form the SCOHs-Ca complexes primarily via interactions with carboxyl oxygen and amino nitrogen atoms. The prepared SCOHs-Ca complexes formed compact nanoparticles and exhibited a fold and porous network structure. These changes could be attributed to the interaction between peptides and calcium ions. Our findings provide a theoretical basis for the development of new calcium preparations as well as the high-value utilisation of sea cucumber by-products.