Speication Changes and Distribution of Calcium in Added Nano Fish Bone during Myosin Gelation

In this work, nano fish bone (NFB) was prepared from silver carp bones and added to silver carp myosin. The speciation changes and distribution of calcium in NFB (NFB-Ca) during myosin gelation were investigated by measurement of various calcium species, surface element analysis, microstructure examination and low-filed nuclear magnetic resonance (LF-NMR). Results showed that the Ca content of myosin with the addition of NFB significantly increased compared to that without added NFB. NFB-Ca existed mainly in an insoluble form in myosin (> 95%). Heating treatment at 40 ℃ significantly increased the ionic Ca content; however, ionic-Ca was transformed into other forms at 90 ℃. Therefore, it was suggested that part of the soluble Ca released from NFB participated in the formation of salt bridges and consequently was transformed into insoluble calcium, facilitating myosin cross-linking. As a result, a continuous and uniform gel network structure was observed under laser confocal scanning microscopy (LCSM). Meanwhile, LF-NMR showed that the compact microstructure could help to hold more water and decrease water mobility. In addition, the surface Ca of myosin with NFB increased, and the distribution uniformity of Ca was improved after heating treatment.