a. Enzymes
1. Types of enzymes present in fish, especially fish processing discards divided into two groups
as either derived from the viscera or from the muscle protein
⑴ Proteases
⑵ Lipoxygenases and transglutaminase
2. The proteases are responsible for many of the deteriorative reactions in seafoods, such as texture
softening in fillets, gaping between myotomes, modori phenomenon in surimi gels
3. They can also be used for a number of seafood processes such as production of fish protein
hydrolusates, fish sauce, or to facilitate roe processing and flavor development
• The viscera proteases
• Muscle proteases
• Collagenase
• Transglutaminase
4. Potential uses for different proteases
- Stickwater treatment to lower viscosity
- Development of fish protein concentrates or hydrolysates
- Development of specific flavor compounds
- Pigment isolation from shrimp shell waste
- Tenderization of squid
- Use in skin and scale removal in fish and membrane removal in roe sacks