Tag George J. Flick

Since bivalve shellfish filter large volumes of water to feed, they can accumulate and concentrate bacteria and viruses from various pollution sources. Among enteric viruses, noroviruses are the leading cause of gastroenteritis in humans who consume affected shellfish. Current wastewater treatments fail to enZsure the complete removal of viral pathogens that can be discharged into fresh, marine and estuarine waters and therefore contaminate shellfish-growing waters. The detection of noroviruses in food relies on molecular techniques. 

Commercially harvested shellfish have been reported to cause gastro-enteritis when humans consume virus-contaminated products. Rotaviruses are one of the main types of viruses able to survive and persist in the aquatic environment. 

Live markets represent a promising niche in regions where locally raised seafood cannot compete with inexpensive imports. Study results suggested regional shrimp producers could effectively reach premium markets by shipping using waterless methods. 

The development of antimicrobial resistance genes in human pathogens as a consequence of exposure to antibiotics in aquaculture is widely documented. Reports implicate foodborne antibacterial-resistant pathogenic bacteria in human disease. 

No antimicrobial agent has been developed specifically for aquaculture applications. However, some antibiotic products used to treat humans or land-based animals have been approved for use at aquaculture facilities. 

Cathepsin D alone and in combination with other cathepsins presents the greatest proteolytic activity on some fish muscles. 

Cathepsins B, D and L are considered critical in fish muscle post-mortem modifications or gel softening during the setting of surimi. 

Iron compounds in fish contribute significantly to lipid oxidation in addition to oxidation mediated by enzymatic activity. The main iron-containing compounds are myoglobin and hemoglobin. 

Slaughter methods can impact product quality. It is recommended that fish be fasted prior to slaughter to clean their digestive tracts. Instant killing minimizes the degradation of tissue quality. Immediate bleeding is more important than the bleeding method. 

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. 

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 use of anesthetics and regulations concerning the ethical treatment of animals. 

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 exogenous enzymes.