**7. Conclusion**

It is possible to recover and utilize compounds from squid wastes, which may represent a potential for increased business and more ways to make a more environmentally sounded use of natural resources from this seafood product. From this wastes or by-products collagen can be obtained.

ACS can be extracted from the muscle jumbo squid with 0.5 M acetic acid with an average yield of 15% from the total muscle protein, and showed comparable biochemical characteristics to the collagen of skin from squid species, but it presented higher transition temperature, similar to type I collagen from bovine skin.

Novel biomaterials from collagen-chitosan blends, with excellent biocompatibility and antibacterial properties can be successfully prepared. One of the applications of these blends is the elaboration of films. Moreover, the interactions between collagen and chitosan may exhibit great potential in areas not much exploited such as plasticizers.

Chitosan, a polysaccharide that is produced by deacetylation of naturally occurring chitin, has a great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, non-toxicity, and versatile chemical and physical properties. Acid soluble collagen/chitosan blends are miscible and interact at the molecular level, although pure chitosan, as a film material, poses low percentage of elongation, it is possible to improve its elasticity with the addition of biodegradable materials. The film properties of the chitosan can be enhanced by adding collagen to the blend, where both polymers interact by electrostatic and hydrogen bonding.

ASC from jumbo squid and chitosan blends are miscible and interact at the molecular level, being hydrogen bonding the most abundant interaction forces between the polymers. These interactions affect the chitosan films properties. Opaque and more elastic chitosan films are obtained by the incorporation of acid soluble collagen.

The general trend of the stress-strain curves of acid soluble-chitosan films was characteristic of elastic films where collagen showing a conventional action of plasticizers (increase in elongation and decrease in strength). Therefore acid soluble collagen from jumbo squid is suitable to be used as additive to improve the elastic properties of the chitosan films.

This chapter only covers a limited introduction to collagen as bio-plasticizer. However, in view of the advances in technologies for recovering collagen from seafood catch and processing discards that should environment friendly and the continue need within the seafood industry to find alternative products, further research efforts should also be directed toward ways to evaluated the industrial potential of collagen as an alternative to traditional petroleum-based plasticizer, and provide its comparison as a chitosan or other polymer plasticizer with other bio-plasticizer.
