Biology Reference
In-Depth Information
Protein Related Compounds
Collagen and Gelatin
By-products from fi sh processing are a potential source of collagen. It is
the main component in the skin (Norland, 1989; Sikorski and Borderias,
1994) that can be collected separately from other by-products. Skin and
bones constitute about 30% of total fi sh weight (Muyonga et al., 2004;
Aewsiri et al., 2008).
Several authors have studied isolation and characterization of collagen
from fi sh wastes (Nomura et al., 1997; Nagai and Suzuki, 2000; Nagai,
2004; Mizuta et al., 2005; Arnesen and Gildberg, 2006). Collagen in the
purifi ed form has a number of applications in pharmaceutical and cosmetic
industry (Borderias et al., 1994). Similarly gelatin, the hydrolyzed form of
collagen, is an ingredient in the food industry. Gelatin is used as a food
additive to increase the texture, the water holding capacity and stability
of several food products (Borderias et al., 1994). The uniqueness of fi sh
collagen from cold water fi sh lies in the lower content of proline and
hydroxy proline (Haard et al., 1994). Although fi sh gelatin does not form
particularly strong gels, it is well suited for certain industrial application;
i.e., micro-encapsulation, light sensitive coatings and low set time glue.
There is also a market for non-gelling gelatin which has a potential in
the cosmetic industry as an active ingredient. Fish collagen and gelatin
generates new applications as a food ingredient because it has properties
different from mammalian collagen (Rustad, 2003).
Protamine and Taurine
Protamine is a basic peptide containing more than 80% arginine. It has been
found in the testicles of more than 50 fi sh species. Protamine has the ability
to prevent the growth of
Bacillus
spores, being used as an antimicrobial
agent in food processing and preservation (Rustad, 2003). Taurine is a
sulphur containing amino acid most abundant in any tissue and is unique
due to the fact that it does not form a constituent of any proteins nor is
it linked to any protein by a peptide bond. Aquatic foods including fi sh
processing by-products are rich sources of taurine (Sakaguchi et al., 1982;
Zhao et al., 1998; Gormley et al., 2007). It has a hypolipedemic effect and is
known to stimulate bile acid synthesis (Ogawa, 1996). The physiological
benefi ts of taurine is a subject of several research works (di Wu et al., 1999;
Liu and Li, 2000; Militante and Lombardini, 2002; Berger and Mustafa,
2003; Fennessey et al., 2003). Fish processing wastes are potential sources
from which taurine can be recovered for further use in both foods as well
as biomedical applications.
