Chemical composition and properties of aquatic food industry waste

The objective of this chapter is to explore the chemical nature of various aquatic waste materials of interest. For this purpose, a comprehensive literature review was conducted by examining data from peer-reviewed journals and industry reports to understand their chemical composition and the technological advancements in extraction. Aquatic food industry waste may come from a variety of sources. Internal organs of fish possess different proteolytic enzymes, namely pepsin, trypsin, chymotrypsin, collagenase, and lipases. Fish bones are useful for the extraction of collagen, Gelatin, as well as minerals like calcium and phosphorus. Moreover, crustaceans and wild salmonids are valuable for the presence of the pigments astaxanthin and canthaxanthin. From a chemical perspective, these waste products comprise proteins and enzymes (marine peptides, collagen, and gelatin), lipids (omega-3 fatty acids), polysaccharides (chitin and chitosan), minerals (calcium and phosphorus), and some bioactive pigments (carotenoids). If extracted successfully, they can be used as functional food ingredients, pharmaceuticals, or in biopolymer industries.