88C-21 |
Effects of parasite attributes and injected current parameters on electromagnetic detection of parasites in fish muscle. |
G. S. CHOUDHURY1, C. G. Bublitz, J. P. Wikswo, and W. G. Jenks. (1) Food & Nutrition Dept., Univ. of Wisconsin, Stout, PO Box 790, Menomonie, WI 54751-0790 We developed an electromagnetic technique to detect parasites in fish muscle based on conductivity difference between the parasite and the surrounding fish flesh. The purpose of this study was to examine if the technique can be expanded beyond the laboratory and become the basis of an automated commercial system. The objective was to determine the effects of a) applied signal strength and frequency, and b) orientation and position of parasite on resultant magnetic field strength. A plexiglass cell having two electrodes, a return cancellation plate, and a port for injecting salt solution was designed and fabricated. The fish fillet, maintained in the sealed cell containing a saline bath of similar electrical conductivity, was injected with current of varying frequency (653 and 2003 Hz) and amplitude (1.1 and 11.6 mA). The magnetic field above the fillet was measured by MicroSQUID magnetometer having pickup coils 8 mm above the fillet. The effect of parasite position relative to myatome structure and blood line was determined using the same cell configuration. However, the orientation effect was determined by placing the extracted parasite in conducting agar having different orientations with respect to current flow. The magnetic field strength is independent of the frequency of the injected current, and scales with current amplitude within the range studied. The parasite orientation affects peak-to-peak voltage of the magnetic dipole (0.16-0.62 V), and the parasite position with respect to myotome seems to affect the orientation of the dipolar signal. No apparent structure due to bloodline was observed. Signals produced by parasites of various orientations located at different positions in the complex fillet are of adequate strength. With further developments, this method has potential for automated parasite detection replacing the manual candling method currently used in the industry.
Session 88C, Food Engineering: Physical and Chemical Properties
|