All methods of slaughter have issues related to animal welfare. However, approaches such as death in air or bleeding without stunning have been particularly cited as unacceptable.
George J. Flick
The methods used to kill fish depend on many factors, including fish size and species, aquaculture production system, fish quantity, market preferences and effects on product quality. Also, some methods may not be approved in some countries, as with the
Mushiness of shrimp tails is often associated with head-on shrimp. Results from the authors’ study, however, indicated that texture values did not vary much between headless and head-on shrimp stored over a two-week period at 4 degrees-C.
Protease enzymes are important industrial enzymes that have diverse applications in food, leather, silk and the agrichemical and pharmaceutical industries. Fish are considered one of the richest sources of proteolytic enzymes.
Enzymes obtained from fish- and shellfish-processing wastes can be used in the making of a number of useful products. Lipase enzymes from fish can break down lipids, while amylases hydrolyze starch.
Fish protein hydrolysates obtained from fish-processing wastes can be used to make valuable ingredients for the food and healthcare industries. Hydrolysates are produced from fish muscle and viscera through an autolytic process by endogenous enzymes or an accelerated method using
Protein hydrolysates can be produced by acid, base or enzymatic hydrolysis processes. Acid hydrolysis produces salt that makes the product unsuitable for food and destroys some essential amino acids. An optimum process for one fish or shellfish by-product may not
Fish protein hydrolysates have been used in the food industry for the development of antioxidants, emulsifiers, flavoring agents, anti-bacterial agents and feed. As natural products, they have a growing acceptance, since natural products are preferred by some consumers over industrial
Overall costs for hand filleting tilapia relate primarily to labor and the throughput of fish to be filleted. Labor is the largest expense. Salaries vary, and cutters’ yield efficiencies increase with practice.