FISH.gov.au

• General rules for storing live seafood     
• Finfish     
• Prawns     
• Crabs     
• Bugs and rocklobsters     
• Freshwater crayfish     
• Abalone     
• Mussels (and other bivalves such as pipis)     
• Oysters

Chilling & storing fresh or wet seafood     

• Benefits of using ice     
• Using ice to chill and store seafood 208     
• Commercial chilling using ice and chillers and/or coolrooms     
• Commercial chilling using ice water     
• Commercial storing of chilled fresh or wet seafood     
• Domestic chilling and storing of seafood

Freezing & thawing     

• Freezing seafood     
• Thawing seafood

Displaying seafood     

• Choosing a display case     
• Setting up a display case

Shelf life     

• Extending shelf life     
• Shelf life table

The tables that follow provide information on how to store live the most common seafood species. The suggested temperature and salinity levels should be considered a guide only, since individuals of the same species harvested in different regions may be acclimatised to different conditions.

• Do keep the seafood cool and moist. This reduces the stress associated with being stored in air. The temperature to which it is cooled depends on the tolerance of the species. Make sure you have a reliable thermometer.
• Do keep the seafood out of bright light as this may cause stress and reduce survival rates.
• Do not disturb the seafood unnecessarily.
• Do not cool the seafood so much that you kill it with cold. Different species have different cold tolerances.
• Do not allow the seafood to come into direct contact with ice.
• Do comply with any relevant animal welfare requirements.

• Do keep the seafood cooler than its normal ambient temperature. This reduces the need for oxygen and enables large numbers of individuals to be stored in a small volume of water, lessens appetite and, in crustaceans, prevents cannibalism under crowded conditions.
• Do operate the tank under conditions of controlled temperature, salinity, pH, dissolved oxygen level (aeration), and levels of excretory wastes that do not stress the seafood (filtration).
• Do keep the seafood out of bright light unless it is on display. Bright light may cause stress and reduce survival rates.
• Do check regularly and remove weak, damaged or dead individuals—do not consume them as the cause of their condition will usually be unknown, and they may pose a health risk.
• Do not try to store seafood with different requirements in the same tank.
• Do not put more stock into a holding tank than it is designed to hold.
• Do not feed the seafood. This can pollute the water and it is not necessary. Live seafood is not likely to starve to death before somebody buys it. Food in the intestinal tract (vein) of some crustaceans also detracts from their appearance.
• Do comply with any relevant animal welfare requirements.

It is very important to respect the appropriate temperature and salinity and to filter and aerate tank water.

Delivered finfish may be in water considerably colder than the display tank, and they may well be heavily stressed. On arrival, you need to:

• open the bags and immediately remove dead individuals (that is, those not breathing);
• aerate the bag water;
• gradually add water from the holding tank to acclimatise the finfish.

WARNING: Disease outbreaks may occur in tanks because of stress imposed during transport. One common disease, “white spot”, is readily identified from small (1–2 mm), white spots on fins and body. Bacterial diseases may occur if finfish are badly damaged and the skin is broken; they usually appear as red ulcers on the body of the fish.

Diseased fish should be removed and treated separately or discarded. Veterinary assistance may be required.

To help avoid drowning crabs that have been stored or transported in air, fully dip crabs (face up) in the tank a couple of times, letting bubbles emerge, before leaving them in the tank.

Other than mud crabs, local species do not survive well out of water, so are rarely handled live.

For mud crabs, keep claws tied at all times (until the crab is dead). This allows easier handling and prevents possible cannibalism.

Do not store if badly damaged, weak (limp legs and tail), dead or recently moulted (that is, if shell flexes easily when pressed).

Bugs are reasonably tolerant of handling and easily kept alive in tanks.

individuals found dead should not be eaten.

They are very hardy, but do not mishandle.

Check conditions daily; remove weak and dead individuals.

Beware of claws.

in general, small individuals last longer in storage than large ones.

When stored out of water, abalone may lose flavour or develop abnormal flavours.

For food safety reasons, storing mussels out of water (dry storage) is preferable to storing them in water (wet storage).

Using ice to cool live mussels in a coolroom or placing them in a chiller below 5°C may be too cold to keep them alive.

Bivalve stock to be kept live must come from approved areas only. Batches of product should not be mixed and each should be labelled with the following:

• where they were cultivated (e.g. which river or estuary);
• the harvest and packaging dates;
• the name of the supplier;
• relevant post-harvest treatment.

This source identification is part of a recall system to allow rapid notification of product defects or food contamination problems.

WARNING: Poor-quality or contaminated mussels can cause food poisoning. Discard if damaged. Gaping shells (exposing the soft tissue inside) should be treated with caution—gently tap shell and observe whether the animal is capable of closing; discard those that do not close.

For food safety reasons, storing oysters out of water (dry storage) is preferable to storing them in water (wet storage).

Using ice to cool live oysters in a coolroom or placing them in a chiller below 5°C may be too cold to keep them alive.

Oyster stock to be kept live must come from approved areas only. Batches of product should not be mixed and each should be labelled with the following:

• where they were cultivated (e.g. which river or estuary);
• the harvest and packaging dates;
• the name of the supplier;
• relevant post-harvest treatment.

This source identification is part of a recall system to allow rapid notification of product defects or food contamination problems.

WARNING: Poor-quality or contaminated oysters can cause food poisoning. Discard if damaged. Gaping shells (exposing the soft tissue inside) should be treated with caution—gently tap shell and observe whether the animal is capable of closing; discard those that do not close.

How well seafood is chilled and stored plays a very important part in protecting and maintaining product quality, while limiting the amount of product spoilage. The seafood handling practices involved will differ slightly between commercial and domestic situations. However, regardless of the situation, ice should be used in the chilling and storing of fresh or wet seafood.

Most fresh or wet seafood should be chilled and stored at a temperature between –1°C and +4°C. ice is best used to achieve this because it:

• can maintain the required temperature without the use of outside power sources like motors or electricity;
• keeps seafood looking its best (ice will not dry out the seafood, and will help keep product weight up and the skin or shell shiny);
• is portable, inexpensive, easy to use (the right type of ice can be easily shaped and placed where it is most required) and maintenance free;
• will not freeze seafood, so quality will not be lost by handling it in a semi- frozen state;
• is a more effective cooling medium than air (ice has a far greater capacity than air to absorb heat from seafood).

EXCEPTIONS: Bivalve molluscs such as oysters can be sprayed with slightly salty, ice- cold water to prevent dehydration and to retain flavour.

Smoked seafood must not be in direct contact with ice as this will cause the odour, colour and flavour to be washed out, and water to be absorbed.

Hard cured seafood must not be chilled; it must be stored away from humidity to prevent reabsorption of water. Preserved seafood that is not hard cured can be chilled, but should be held at a constant temperature to avoid condensation, which will similarly cause water reabsorption as well as the growth of moulds.

Use snow, flake or shaved ice between the products when chilling and storing fresh or wet seafood. These types of ice are easy to work with and do not cause physical damage (indentations or bruising).

Tubed, cubed or crushed ice can be used on top of seafood being chilled and stored. These types of ice will not fall away from the product like snow, flake or shaved ice as they melt. They will become smaller, but will remain in contact with the product for a much longer time before completely melting.

Place the seafood in the ice, not on it. This is much easier to do if snow, flake or shaved ice is used.

ice should be placed on the top and bottom, and spread between the seafood, in order to maintain the desired temperature of between –1°C and +4°C.

Replace ice as it melts or becomes contaminated. Never re-use ice—it may be dirty, soiled by blood, or full of bacteria that could contaminate any seafood it comes into contact with.

• for chilling, 1 kg of ice to 1 kg of seafood;
• for storing, 1/ 2 kg of ice to 1 kg of seafood.

ice must be made with potable water that is not salty. ice made with salty water requires colder temperatures to remain solid. Consequently, it can cause repeated slow partial freezing of the seafood, which will significantly harm quality. Melted ice water is not as cold as ice and should not be relied upon alone to chill seafood.

Do not store seafood in ice for long periods. Holding chilled seafood at a proper storage temperature using ice will eventually be detrimental to its quality.

Sort and grade the seafood and then wash it thoroughly in cold, running potable water to clean and help pre-chill it before packing. Do not wash it for too long. Shake it gently to remove excess water. Washing and pre-chilling should extend the shelf life of the seafood by slowing down the rate of spoilage.

Use shallow, clean containers (tubs, bins or trays) to chill seafood (see below for an example). A shallow tray-type container allows for better overall chilling than a bowl-shaped container. Plastic liners can be used for worn or stained containers, but using unblemished containers is far preferable.

The qualities of a good seafood container :

• rounded corners for easy cleaning
• suitable stacking arrangement so that product is not squashed
• not too deep
• contents marked
• containers nest when empty
• plenty of room for fish and ice
• smooth, hygienic surface
• individual fish completely surrounded by plenty of ice

A sealed container helps:

• maintain the required temperature;
• minimise temperature fluctuations;
• prevent dehydration;
• prevent contamination through spillage.

Separating stacked containers with plastic sheeting can replace the use of fitted lids, provided a lid is used on the top container.

Despite the advantages of lids, leave them off packed containers until the seafood reaches a chilled temperature somewhere between –1°C and +4°C.

This will help speed up the chilling process.

Stainless steel or glass containers are more suitable for the quick chilling of seafood than those of plastic or polystyrene, which both have insulating properties that extend the time required to chill. Once the seafood is chilled, and can be kept chilled, any of these containers are suitable.

Do not over fill containers with seafood as this results in squashed product that is difficult to chill, and containers that are difficult to stack.

Remember to use plenty of ice on top of, underneath and between the seafood. Ensure that seafood flesh does not come into direct contact with the ice.

Stand seafood upright (i.e. belly down for finfish), slightly apart, to allow ice to better mix throughout the product. This leads to better and quicker product chilling and less squashing than if the seafood is placed on its side. Fillets should lie flat and only two layers deep, to help protect them from squashing. if fillets are left on top of large piles they have an increased tendency to gape, favouring the entry of bacteria and speeding up the spoilage process. Fillets should be placed skin-side up (even if the skin has been removed).

Gilled and gutted and dressed finfish and large crustaceans should be stored in a single layer only, belly down and with the head end lower than the tail end. This facilitates quick drainage of liquids through the belly region (where most bacteria gather) and away from the flesh. Sellers often store large crustaceans with the head up to prevent fluid (and hence weight) loss. This is not recommended for maintaining quality or prolonging shelf life.

Molluscs in half-shell should be placed with the shell in a cup-shape position and with a sheet of plastic between layers. This prevents the shell above from contaminating the meat below.

With longer term storage, create continuous drainage by placing the seafood on a perforated tray with a non-perforated tray underneath to catch the melt- water. The seafood must not lie in its own fluids or melt-water as the flavour and colour will leach out. Regularly check the drainage and dispose of the fluids.

Such fluids are the cause of many bad odours detected in seafood work areas. Create drainage

The lower the temperature, the longer the shelf life of seafood. However, below –1°C partial freezing will occur, which will significantly harm the quality of seafood. As fluctuating temperatures can also harm quality, the temperature must be checked regularly and often, using a probe thermometer in the top, bottom and middle sections of the packed seafood. Chillers and coolrooms, etc. should be fitted with fixed thermometers connected to alarms.

Some fishing vessels use a combination of ice and water to chill their catch. This method is also effective for chilling seafood in food service operations, if the following precautions are taken:

• Clean ice and potable water should be used, to reduce chances of cross contamination. The amount of ice required will depend on the type of ice being used.
• The combination of ice and water should be well mixed to create an even temperature. Stir well before adding any seafood products.
• Whole products are best suited to this method of chilling. if exposed seafood flesh is to be chilled in this way, it should first be packed in a watertight package (for example, a sealed plastic bag) to avoid contact with the ice water.
• Pre-chill the seafood using cold, running potable water or by placing it in the chiller for a short time before immersing it in the ice water. This will help speed up the chilling process.
• Carry out temperature checks every two to three hours after adding the seafood. Make sure the ice–water mixture remains between –1°C and +4°C, especially when the seafood is needed in the fresh or wet state.
• in some cases, salt may be added to the ice water to help retain the expected taste and flavour of the seafood. An example is whole cooked prawns, where plain ice water could reduce the salt content of the product. it is best to use only as much salt as will satisfy one’s taste: avoid making a “brine” (large quantities of salt mixed with water).
• When ready, the ice water, along with the added seafood, should be placed in a chiller to help maintain the required temperature.

To ensure that the quality of seafood does not deteriorate when stored in a commercial chiller, food service operators need to adopt the “using ice” practices described above, and the following storing practices:

Chillers should operate between temperatures of –1°C and +4°C. if the temperature falls below –1°C, fresh or wet seafood begins to freeze.

install an alarmed temperature recording system inside the chiller to monitor the temperature of the air. This will reveal any temperature fluctuations that could result from poor or excessive use of the chiller.

Prevent an excess of warm air from entering the chiller by fitting a heavy-duty plastic curtain over the point of entry. The entry of excessive amounts of warm air causes temperature fluctuations and “frosting up” within the chiller. Use appropriate temperatures

Store seafood containers off the floor and away from the walls. This will allow chilled air to circulate; appropriate shelving may need to be installed.

The name of the product and the date should be clearly placed on the container before storing, so that the product can be identified and a first in, first out routine practised.

inside the chiller, store ready-to-eat seafood, such as half-shell oysters and cooked prawns or crab meat, on the top shelves. Raw seafood containing liquids, such as fresh squid or octopus, should be enclosed in plastic bags, packed in ice, and placed on the bottom shelves. The rule of thumb is “the more the seafood is prepared for eating, the higher on the shelves it should be stored”. To avoid possible ammonia contamination, store shark (flake) and ray products away from other products.

All seafood stored inside a chiller should be covered; cling wrap or food-grade plastic sheets are appropriate. Lids on containers will help maintain product temperature, and avoid unnecessary contamination, dehydration and oxidation of the stored seafood. When containers are stacked only the top one needs a lid.

TIPS:

• Chillers should be completely emptied, cleaned and sanitised (including equipment such as shelving and containers) once a week, to avoid any build-up of dirt or waste. Bacteria responsible for both food spoilage and food poisoning may other wise grow to unacceptable levels.
• Open the chiller door as little as possible. Opening the door introduces warm air, causing temperature fluctuations that accelerate spoilage.

Ensure that your refrigerator is clean and in good working order, with tight seals. This will minimise temperature fluctuations and prevent contamination that could spoil stored seafood.

Domestic refrigerators should maintain a temperature close to +4°C. Use a thermometer to check the temperature of your refrigerator and, if necessary, adjust it downwards when storing seafood.

Shallow sealed containers should be used for storing seafood. Mix ice through seafood stored in a refrigerator to help keep it chilled. Normal ice cubes made in the refrigerator’s “freezer” are appropriate. Wrap the seafood in cling wrap or a sealable plastic bag to avoid direct contact with the ice. Remove ice melt- water regularly or place the seafood on a cake cooler in the container so that melt-water collects below the seafood.

Place fish fillets flesh-to-flesh, leaving the skin side exposed. This keeps the flesh side moist and the skin (if left on the fillets) acts as a barrier to unwanted bacteria. (Fillets often hold together better when cooked with the skin on.)

Store raw seafood below cooked and ready-to-eat seafood. This will prevent raw seafood from contaminating cooked or ready-to-eat product in case of a spillage or accidental contact between the two.

Store all seafood products as low in the refrigerator as possible, so that if a spillage does occur it will not contaminate other products. The coldest part of the refrigerator will be at the bottom or in a designated chilling zone.

TIPS:

• Clean out the refrigerator at least weekly and never store seafood longer than necessary. The quicker seafood can be eaten (kept moving), the more likely it will be of better quality and safer to eat.
• Open the refrigerator as seldom as possible. This will help reduce temperature fluctuations that accelerate spoilage.

Freezing of seafood takes place when its heat is removed and the water within the seafood changes from a liquid to a solid. Removing the heat is the job of a freezer. Freezing can protect the quality of seafood, and increase its shelf life.

The terms “freezer ” and “cold store” are often used interchangeably, but refer to mechanical equipment that in fact serves very different functions:

• a freezer is used for the freezing of food.
• a cold store is used for the cold storage of frozen food.

A cold store (sometimes called a “cold room” or a “cold storage facility”) should never be used for freezing seafood, as it is not designed for that purpose. Most food service operations are fitted out with cold stores, not freezers.

The freezing of seafood should never take place in the same equipment that is used for its cold storage. The rate at which seafood freezes in a cold store (known as “slow freezing”) is too slow, taking longer than two hours for the core temperature to reach –7°C or below. Slow freezing brings about the formation of large ice crystals in the cells of seafood, which damage cell membranes and cause them to leak when the seafood is thawed. This leads to a loss in weight and a reduction in quality (for example the seafood gapes and is dry and tough when eaten). Furthermore, placing unfrozen seafood into a cold store can increase the ambient temperature, thereby detrimentally affecting the quality of other product stored there.

if the freezing of seafood is carried out in a freezer (i.e. correctly) the rate of freezing will be rapid, taking under four hours to reach the required core temperature. This is known as “quick freezing”. Any spoilage problems created by the process of slow freezing will be avoided. However, the equipment required is more expensive, and its operation demands technical knowledge.

The types of freezers used to freeze seafood include the following:

Blast or snap freezers are generally used to freeze seafood packed in thick, irregularly-shaped cartons. Fans blow very cold air at a high speed over, under and around the seafood, which is laid on trays or racks.

Plate freezers are used to freeze products in rectangular blocks 80–100 mm thick. The seafood is packaged and laid between two metal plates with refrigerant circulating through them. The plates are brought together, both compressing and freezing the product.

Brine or immersion freezers are used to individually freeze products such as “fish fingers”. The seafood is immersed in a cold liquid suitable for food. This liquid should have good heat transfer characteristics and low viscosity at low temperatures, and should not affect the flavour, texture, colour or appearance of the product. A concentrated solution of salt and iced water is often used.

Cryogenic freezers are used for small seafood portions requiring quick freezing such as plate-size fish fillets. Liquid nitrogen or carbon dioxide, which are very low-temperature refrigerants, are used to quickly freeze seafood.

Frozen seafood deliveries should be inspected for quality (appearance, odour, texture and taste—see p. 183) and temperature. Delivery temperature should be – 18°C or below depending on the species. if in doubt about quality, thaw a sample.

Do not accept delivery of frozen seafood if its temperature is higher than –15°C. if it must be accepted, inspect the seafood to make sure it is of the required quality before offering it for sale. Both the safety and quality of frozen seafood are compromised when it is not held at –18°C or below.

The range of frozen seafood products available for purchase reduces the need to use the home freezer for freezing seafood. The home ?freezer ?, like the chest “freezer”, should be used only to keep frozen products frozen. They are designed for cold storage, not for the freezing of food.

However, home freezing of seafood is popular due to the amount of fresh seafood brought into some homes by the family fisher. For best results the following guidelines should be followed when freezing seafood at home.

Only seafood clearly recognisable as of highest quality should be frozen. The poorer the quality of the seafood at freezing time, the poorer the quality once thawed.

Freezing finfish whole or gilled and gutted produces a higher-quality product. Moisture is retained and dehydration and oxidation are slowed.

Prepare the seafood for freezing by washing it under cold, running potable water. This reduces the number of unwanted bacteria and helps pre-chill the seafood.

Without drying the seafood completely, wrap it tightly in cling wrap or a similar product. Place it in a freezer bag, expel the air and seal.

Label the freezer bag with the name of the seafood and the date. Never forget what is stored in your “freezer”, and remember that first in should be first out. Never refreeze seafood as its quality will deteriorate.

Place the seafood either against the sides of the “freezer” or on the floor. Along with pre-chilling, this helps speed up the freezing process.

The temperature of the “freezer” affects how long the seafood should be kept frozen. Seafood stored around –15°C should be eaten as soon as possible. Temperatures of –18°C or below are required for longer-term storage.

Place a thermometer in the “freezer” to keep a regular check on the temperature. Open the door as seldom as possible.

Once frozen, seafood can be removed from the “freezer”, unwrapped, dipped under cold, running potable water, and then rewrapped for freezing. This coats it with a glaze that helps reduce dehydration during its time in storage.

Before frozen seafood can be consumed and enjoyed, it must be thawed correctly so that its quality is retained (but see “Exceptions” below).

Poor thawing practices can cause thawed seafood to:

• lose weight and increase in toughness (as moisture is lost);
  
• have its quality and shelf life greatly reduced;
  
• cook unevenly.

The methods used for thawing frozen seafood include:

• slow thawing in a chilled atmosphere—commercial chiller or coolroom or domestic refrigerator. This is the best and most common method;
  
• microwave oven—now being used more frequently in domestic situations;
  
• circulating cold water—used when rapid thawing is required.

These methods are explained on the following pages.

Once thawed, seafood should be cooked as soon as possible. I if it is not required immediately, it should be treated as any other seafood and properly prepared for storing (see p. 212). Label it with the date and time it was removed from the freezer.

Do not refreeze seafood. Refreezing will reduce quality and can increase the chances of microbiological spoilage. Therefore, to avoid wasting seafood, thaw only the quantity required (if possible).

EXCEPTIONS:

• very small finfish need not be thawed before cooking.
  
• pre-crumbed, battered or sauced seafood products that are specifically intended to be cooked directly from the frozen state should not be thawed because:
  
  • the moisture from thawing can cause the crumbs or batter to become soggy and fall off;
    
  • the soggy crumbs or batter remaining on the seafood will absorb more oil and not provide a crisp, sealed coating.

Frozen seafood can take up to 40 hours to thaw using the slow thawing method, depending on the species and quantity. Record the thawing times for different seafoods and quantities. Keep these times on hand so you know when to remove seafood from cold storage.

Decide well in advance what needs to be thawed so that ample time can be allowed. Rushed thawing will result in poor-quality wet seafood.

Remove any outer packaging material that will insulate the frozen seafood, as it will extend thawing time. However, always keep any inner plastic wrap in place when thawing seafood, or cover it with cling wrap or place it in a sealed container. This helps to protect it from dehydration and contaminants.

Break frozen seafood cartons down to their smallest single unit. The smaller and thinner the package, the quicker it will thaw.

Place the frozen seafood in a chiller with good air circulation and, ideally, at a temperature of between –1°C and +4°C. Seafood thawed above +4°C will:

Place the seafood to be thawed in a container (bin, tub or tray) fitted with drain holes. Place this container on, over or in another tray or container to catch drained liquids. These liquids must never be allowed to spill.

Seafood should be named and dated when placed in the chiller for thawing. This helps ensure that seafood first thawed is first out.

Thawing seafood should not be physically handled until thawing is complete. This helps protect and maintain its quality.

Most methods of commercial slow thawing of frozen seafood apply equally well to domestic slow thawing. However, the following adjustments are required:

Seafood should be placed in the lower part of the refrigerator to limit the chance of cross-contaminating other foods. Always thaw frozen seafood in a refrigerator (never at room temperature), to protect and maintain its quality.

Place the frozen seafood on a cake cooler, stand it in a shallow baking dish and then cover it. This keeps the seafood above the melt-water and helps avoid cross contamination.

Open the refrigerator sparingly when using it to thaw frozen seafood. Undue opening will encourage temperature fluctuations, which will affect the quality.

Check the thawing seafood regularly (every two hours if possible). Once it is completely thawed remove it from the refrigerator, wash it under cold, running potable water, place it on a clean cake cooler, placed in or on a baking dish, cover it and return it to a lower shelf in the refrigerator until required.

Seafood displays play a major role in attracting customers’ attention and influencing their purchasing decisions. Therefore, much effort should go toward creatively and hygienically preparing a display case. Regardless of whether the seafood is fresh, wet or frozen, cooked or raw, displayed in a retail fish shop or a restaurant smorgasbord, most good seafood display practices are the same. The presentation of the display clearly indicates to consumers the service operator’s commitment (or lack of it) to seafood safety and quality.

The purpose of a display case is to display seafood to its best advantage while protecting and maintaining its safety and quality. This can be achieved by using specially designed equipment that will minimise physical damage, contamination, temperature fluctuations, oxidation and dehydration. It is false economy to display seafood in equipment not specifically designed for displaying seafood. Similarly, display cases should never be used to chill, freeze or thaw seafood.

Both enclosed and open seafood display cases are used by food service operators for displaying seafood.

 An enclosed seafood display case (below) should be used to display all seafood, whether cooked or raw, that is ready for immediate consumption. Example of a well-designed enclosed seafood display case

• Fully enclosed (glass panels)
• 12” to 22” slope for display slab
• Ventilation for motor
• Legs that allow 300mm off the floor (for cleaning)
• Display slab insulated and refrigerated
• Internal thermometer for monitoring temperature
• Evaporator coil to cool incomming air.

In addition to the features illustrated, enclosed display cases should be fitted with:

• wide drains running as straight as possible into a floor waste drainage system (waste fluids need to drain away quickly to prevent spoilage problems and straight, wide drains are more difficult to block);
• blue-tint fluorescent lighting, which shows seafood to its best advantage without causing excessive heat.

The use of open seafood display cases, such as those seen in modern seafood premises and restaurants promoting “all you can eat”-style dining, is increasing. But open seafood displays pose a higher risk of serving customers seafood of unacceptable safety and quality. Open seafood displays (and similar presentations such as buffet-style meals) are highly susceptible to spoilage problems, and should always be attended by staff members well trained in food safety and displaying seafood. The figure--below illustrates the appropriate construction of such a case.

Laying out seafood in a display case should be viewed as a creative process.

The display can be an effective selling tool. I if appealing, it can improve customers’ perceptions of the seafood, and increase their satisfaction with the service.

Choosing a good layout for a seafood display case will help control the temperature as well as protect and maintain the safety and quality of the seafood. The three common arrangements—chevron, free-form and front-to-back—are shown on the opposite page.

The most commonly used layout is the front-to-back, but the chevron and free-form allow best chilled air circulation around and between the displayed seafood.

Front-to-back layouts can create problems, including:

• lack of room for chilled air to circulate;
• cross contamination and product substitution (when space between seafood types is insufficient and/or overfilled trays spill over);
• dividers between the “ribbons” (or rows) of seafood that act as barriers preventing cold air from circulating throughout the whole display case. Also, the dividers may not be high enough to prevent the spillage of displayed seafood into another tray.

Selecting the right layout

The following seafood handling practices should be adopted when preparing display cases for chilled or wet seafood. Most of these practices also apply to displays of frozen product. However, all frozen seafood should be displayed in a cold storage facility.

Steps to follow to prepare a display case for seafood:

1. Ensure that the display case is clean and in good working order—this will significantly reduce the risk of contamination.
2. Pre-chill all the seafood to be displayed.
3. Cover display slab with a thick bed of flake, snow or shaved ice (10 cm thick for enclosed displays and 20 cm thick for open displays).
4. Slope the ice bed between 12° and 22° for product visibility and to maximise cold air flow.
5. Clean, sort and grade the seafood.

 The following points must be considered when adding seafood to a display case:

Place clean stainless steel or glass trays on the ice; these materials have good thermal properties and help keep the seafood chilled. Avoid using plastic or polystyrene trays, which are effective insulators. The trays must have drain holes.

Never overload a display case, as this will make it difficult to maintain the appropriate chilled temperature of –1°C to +4°C. Spread the seafood out and refill the display case directly from the chiller as required.

Do not display seafood in heaps, piles, stacks or bowls, as this will make it difficult to adequately chill the product in the middle. Fillets, cutlets or steaks should be no more than two layers deep.

Separate different types of seafood. Do not place raw seafood where it can contaminate, or has to be lifted over, ready-to-eat products. Place lighter-coloured flesh where it has to be lifted over darker-coloured flesh rather than vice versa. (Darker-coloured flesh can easily stain lighter-coloured flesh, spoiling its appearance.) Separate seafood from all other foods.

 Help whole and gilled and gutted finfish maintain their chilled temperature by ensuring that they are placed in the ice, not just on it.

Never hang seafood on hooks; this will damage it and will not improve its quality or extend its shelf life.

Display crabs, rocklobsters and bugs in ice with the head and mouth pointing downwards. This prevents dirty meltwater from entering the seafood and encouraging contamination.

Display half-shelled molluscs (such as oysters) in ice, two layers deep with each layer separated by a barrier film (plastic sheeting) so that the bottoms of shells do not come into direct contact with exposed meat.

Do not allow exposed seafood flesh to come into direct contact with ice.

Use whole, smooth-skinned fruit and vegetables, such as tomatoes, capsicums and eggplants, to decorate a display case. These types of fruit and vegetables are much easier than others to keep clean, thereby helping to avoid cross-contamination problems. Do not use fruit wheels or slices made from citrus fruit (such as oranges and lemons): they can stain or discolour seafood flesh through direct contact, and have a poor appearance when dried out.

Do not spike the seafood with a label, or pierce its flesh in any way. Doing so will reduce its shelf life and lower its quality. Use whole fruit or vegetables to stand labels up.

Always label seafood with its approved Australian marketing name, and clearly identify imported seafood as such. Label seafood as “fresh” only if it has never been below the temperature of –1°C; label it as “frozen” only if it has not been above –1°C since its initial freezing. These labelling practices are currently in accordance with the Food Standards Code.

The older the seafood, the more conveniently it should be placed in the display case, so it can be consumed (sold or eaten) first.

Wash your hands whenever you handle different products or change tasks, before, during and after setting up a seafood display case.

 Once a case is packed for display, the following practices should be followed:

Do not handle seafood with bare hands; use or supply tongs. This is better than using gloves, which can cause cross contamination. Another option is to select the required seafood with your hand inside a clean plastic bag. Holding the seafood, draw the mouth of the bag down your hand inverting the bag over the seafood. Release the seafood while holding the bag shut with the other hand.

Use separate serving utensils for all products on display to help avoid cross contamination.

Spray seafood with potable ice water every hour to prevent dehydration. Keep the water bottle on ice when not in use.

If necessary, place tubed, cubed or crushed ice on top of the seafood. Do not allow ice to come into direct contact with exposed seafood flesh.

Regularly observe the display case from the customers’ viewpoint and make changes as necessary.

 Do not use a seafood display case for thawing seafood.

Regularly check the temperature of the seafood and the air within the display case. This will reveal the size of any temperature fluctuations that are taking place, so that remedial action can be taken. Temperature fluctuations cause

Chest-type frozen-food cases are the most common method of displaying frozen seafood but upright cases are also used. I if the quality of frozen seafood is to be protected while on display, the following guidelines should be followed:

The case should be located out of the direct sun and away from any draft, so as not to reduce its performance.

The temperature of the case should be –18°C or below, and checked every two or three hours, to ensure that it is cold enough to keep the frozen seafood on display in the best possible condition.

Non-self-defrosting frozen display cases should be defrosted regularly so that their performance is not affected. Frozen display cases left to “frost up” are ineffective (they do not maintain the required temperature), and costly to operate.

Never stack frozen seafood above the load-limit line. Seafood above the line will be exposed to warmer air than seafood below the line and may begin to thaw.

Tightly pack the frozen display case to minimise air pockets (but do not pack them so tightly that they are difficult to remove). Air pockets can cause partial thawing of frozen products on display.

Dividers should be used to keep the frozen display case from becoming untidy. Customers will not find an untidy display case appealing and a loss in sales may result.

Thawed seafood should not be displayed in a frozen-food case. The purpose of these cases is to keep frozen seafood frozen while on display.

When restocking the frozen seafood display case, place new product under or behind the old, so that a first in, first out system can operate.

Once a week, the display case should be completely emptied and thoroughly cleaned and sanitised. Display cases that are not presented clean and free from unwanted odours may affect sales.

The shelf life of seafood (i.e. the time it can spend “on the shelf” before it must be consumed or discarded) depends on a large number of factors such as the catching method (for example crabs caught in a pot have a longer shelf life than those caught by trawl), the condition of the seafood at the time of capture or harvest, the handling practices used, and any exposure to hazards. Shelf life can be extended by following guidelines such as:

• freezing or chilling the seafood quickly after capture;
• subjecting the seafood to minimum stress when alive (this is influenced by such factors as the catching, handling, storage and transportation methods);
• using correct packaging;
• always storing seafood at the correct temperature.

These shelf life figures are based on an industry census and not on scientific tests. The table is a guide only.

(1) Shelf life for chilled seafood was calculated on the assumption that the seafood:

• was delivered three days after capture (in reality this period will fluctuate and retailers should check with their suppliers as to when the seafood was caught);
• was received in very good condition;
• was stored in the chiller in ice and held between –1°C and +4°C;

(2) Shelf life for frozen seafood was calculated on the assumption that the seafood:

• was delivered two months after being caught and frozen (in reality, this period will fluctuate and may be longer when the seafood is imported, so retailers should check with their suppliers);
• was received in very good condition;
• was quick frozen shortly after capture;
• was stored correctly at –18°C or lower.

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* Most uncooked frozen shellfish (i.e. prawns, crabs, bugs, rocklobsters, freshwater crayfish, mussels and oysters) should be cooked immediately after thawing.