Non-invasive Assessment of Fish Freshness with Bio-impedance and BP-ANN Method

Fast and accurate evaluation of fish freshness has a scientific and practical value for preservation, deposit and further processing of fish. Bio-impedance method, which was widely used to diagnose and monitor diseases of body in medical area, was employed to research on fast evaluation freshness of freshwater fish. A bio-impedance measurement system for freshwater fish was constructed based on LabVIEW with four electrodes and sweep frequency method. The bio-impedance characteristics of fish crucian was investigated during its storage. The result indicated that the impedance and phase changed with the loss of fish, when using BP-ANN method to build model to fish freshness, the accuracy is 94.44%. Application of bio-impedance measurement provides a new and fast method to determine fish freshness.