Fish Meal Descriptions and Photomicrographs
Sponsored LinksFish meal is produced by either wet rendering or dry-rendering. Most fish meal used in animal feeds is manufactured by the wet method where the fish are cooked with steam under pressure, subsequently pressed to remove most of the oil and some of the water, and then dried to a moisture content of 6 – 8%
Macroscopic Features
1. The particles are varying in color and shapes.
2. Muscle tissue is very similar to tissue in meat products.
3. Most fish meal has a slightly greasy texture, in varying color from yellow though brown to dark brown, has a fishy odor and contains fractions of bone and scale.
Stereomicroscopic Features
1. Fine particles appear granular and large particles are rough surfaced, partially retaining fibrous structures very similar to meat products, yet are more finely striated.
2. Fish bone features vary depending on the kinds of bone from different parts of the body (head, body, tail, fins, abdomen).
3. Fish bones vary in color (blue-white, pearly luster, some pieces show an amber color) and are different in size and shape (long, pointed or vertebral form).
4. Scales are flat or curled, almost transparent with concentric markings.
5. Fish meal contains crystalline eye lenses showing spherical milky glass beads and with broken surfaces.
Histological Features
1. Fish meat is finely striated muscle when compared with meat meal.
2. Fish scales are flat or curled, almost transparent with concentric rings which appear as alternating dark and light bands. Faint cross-hatching on surface of the scale is also characteristic.
3. Fish bones are thin, pointed and easily broken with a pearly colored surface sheen. Lacunae fusi-form and has many canaliculated.
4. Fish skin fragments are shiny and have varying colors (gray-blue, violet to almost black) with scattering wrinkles in some parts.
March 04 2008 08:03 am | Article