Glossary

Term or Phrase

Reference Explanation

Anaerobic bacteria

Bacteria that can live without oxygen. An example is Clostridium botulinum is a type of bacteria which can cause the serious food poisoning known as botulism.

Anaerobic

This means no oxygen.

Bacteria

These are single celled organisms. They are commonly called germs. Bacteria do not usually like low temperatures, dry conditions,or high salt, acid or sugar strengths. High temperatures can kill bacteria.

Black spot

See Melanosis in this glossary

Brine

A mixture of salt and water. This will lower the freezing point of water to below 0°C and can be used to start to process of freezing or to store chilled seafood.

Candling

Holding fillets up to a strong light and looking for dark areas which might indicate parasites (or bone pieces).

Chill

Reduce the temperature to between –1°C and +4°C.

Chiller

An insulated room kept at a temperature between –1°C and +4°C.

Chiller thaw

To thaw frozen seafood in a chiller – this ensures slow thawing and minimizes quality loss and is the preferred way to minimize bacterial growth.

Cold room

An insulated room for storing frozen seafood. The temperature is less than -18°C (ideal is -25°C for most seafood but colder for some species e.g. tuna).

Contaminant

Any biological or chemical agent, foreign matter, or other substances not intentionally added to food which may compromise food safety or quality

Control

Any action or activity that can be taken to prevent or eliminate a food safety hazard or reduce it to an acceptable level.

Coolroom

A facility for storing live seafood at a temperature that is suitable to keep them alive.

Critical Control Point (CCP)

A step at which a control can be applied and is essential to prevent or eliminate a food safety hazard or reduce it to an acceptable level (Codex 1997).

Cross contaminate

This means to transfer bacteria from one food to another. This is usually caused by poor food handling methods. Transfer can be from food to be eaten on board (e.g. your lunch) to seafood or from one seafood type to another.

Cryogenic freezing

This is a very quick freezing process that uses liquid carbon dioxide or nitrogen as the coolant.

Dehydrate

To dry out. This results in a drop in seafood quality. But it can preserve seafood so it can last for a very long time.

Detergent

This is a chemical used to clean. The detergent acts like soap to help move dirt off the surface. Some bacteria are also removed and some are killed by detergents.

Enzyme

A protein that helps chemical reactions to occur. Enzymes are important for life but in food for eating they also can cause spotting and other loss of food quality.

Freezer

A piece of equipment that will bring the temperature of the seafood down rapidly. The core temperature of the seafood will reach –18°C to –25°C (or lower) and the seafood can then be moved into a cold store.

Glaze

A protective ice layer on seafood (to prevent dehydration and freezer burn.

HACCP

Hazard Analysis Critical Control Point system – a system which identifies, evaluates and controls hazards which are significant for food safety.

Hazard

A biological, chemical or physical agent in food with the potential to cause an adverse health effect.

Histamine

A substance released from finfish if temperature control is not correct. Histamines in humans cause swelling. This can cause allergic fish poisoning reactions in some people. It is sometimes associated with mackerel, tuna and bonito and is called scombroid fish poisoning.

Hygiene

The science of keeping people healthy – usually by practices that ensure cleanliness.

Immersion freezing

Placing seafood in a liquid which will start the freezing process. Brine is commonly used.

IQF

Individually quick frozen. Each item of seafood (e.g. an individual whole fish or a fillet or a single prawn) is individually frozen and glazed before storage. This allows easy separation and thawing of individual pieces (compared with block freezing where a whole block must be thawed at once). Seafood can be also stored in a layer pack or shatter pack so that individual pieces can be separated without thawing the whole pack.

Melanosis

A change in colour due to the action of enzymes. It is common in prawns and is called black spot or black head. It is caused by poor handling (allowing the prawns to get too warm). Sodium metabisulphite and potassium metabisuphite are chemicals used to slow melanosis.

Oxidation

A chemical reaction with oxygen. This can result in browning or yellowing of seafood and fats become rancid. This lowers the quality of the product

Pathogenic

Causes disease.

Quality

This refers to the external and internal properties of the seafood that are required by a customer. These properties may include visual quality (e.g. colour), eating quality (e.g. smell, taste and texture), and nutritional quality (e.g. fat content).

Quick freeze

To freeze seafood to less than –7°C in less than two hours. This forms smaller ice crystals than if a slower freezing is used and so causes less damage to the flesh.

Rancid

Fat that smells and tastes bad because it has been subject to oxidation.

Spoiler

Something that reduces the quality of seafood. This can be caused by poor temperature control or bad handling.

Wet seafood

Seafood that has been frozen but is now thawed.