NMFS NUMBER: 95-NER-098
of a Rapid Non-Destructive Technique to Measure Fat Content
Dr. David Julian
National Marine Fisheries Service, Northeast Region, One
Blackburn Drive, Gloucester, MA 01930-2298. PHONE:
was to ascertain the relationship between the ultrasonic
properties of fish and their composition. Fish analogs
with varying protein (15 to 25wt%), lipid (0 to 25 wt%)
and moisture (55 to 80 wt%) contents were prepared by
mixing dried cod powder, sunflower oil and distilled water.
The temperature dependence of the ultrasonic velocity
of fish analogs was measured from 5 to 35 C. The
ultrasonic velocity increased with solids-non-fat at all
temperatures, but had a more complex dependence on fat
content. Around 15 C the ultrasonic velocity was independent
of fat, at lower temperatures it increased with fat, and
at higher temperature it decreased. Empirical equations
were developed to relate the ultrasonic velocity to composition.
Our results highlight the potential of ultrasonic
velocity to composition. Our results highlight the potential
of ultrasonic velocity measurements to rapidly and nondestructively
determine fish composition.