La pérdida y el desperdicio de alimentos en las cadenas de valor del pescado
©FAO/Omar Penarubia
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Application of Appropriate Technology for Fresh Fish Retail

Several important technology issues affecting fresh fish retail food loss and waste (FLW) are

  • the fish counter or display
  • the use of ice
  • the use of packaging for fresh fish
  • technology for mobile fish retailing

Fish Counter and Display

Fish Counter and Display

Fish counters or displays are found in super markets, fishmonger shops, and in wet fish markets. In its crudest form, fish can be displayed to consumers on a piece of sacking or matting placed on the ground. On the other hand, fresh fish are displayed in purpose made refrigerated stainless-steel cabinets. In wet fish markets and fishmonger shops, the display is on marble slabs or similar impervious material, such as tiles. The display technology or method has a key influence on the storage life, the quality of fresh fish, the marketing of fish to the consumer, and the speed of sale.

The design and construction of display surfaces must: 

  • Utilize non-toxic materials or coatings, especially those in direct contact with products  
  • Be able to be cleaned easily and remain clean to provide hygienic display conditions (e.g. the use of smooth impervious materials, such as stainless steel, plastic, glass, etc.) 
  • Use non-chip, non-rust surfaces with smooth joints and rounded edges. 
  • Adequately maintain the quality of the products whilst on display. 
  • Adequately prevent contamination of products on display from external sources. 
  • Meet legal requirements. 
  • Use chilled cabinets to maintain the temperature of products between 0°C and 4°C – not to cool products down to this temperature range.

Use of Ice

Use of Ice

The use of ice in fresh fish retailing is an essential control mechanism for FLW. Ice is used to cool products on display to the desired chilled storage temperature (generally between 0°C and 4°C). Even if refrigerated displays are used, ice is still used. Ice is used to: 

  • Maintain the temperature of products on display within the 0°C and 4°C temperature range in order to minimize loss of product quality through spoilage 
  • Insulate products on display from fluctuations in ambient temperature or other sources of heat ingress 
  • Prevent dehydration or desiccation of the products by providing a surrounding atmosphere of constant humidity. 
  • Enhance the visual appearance of products and desirability for eating by consumers (e.g. moist surfaces imply soft texture, ice implies coolness and therefore freshness of products) 
  • Provide physical support for products on display. 
  • To provide a suitable ‘space-fuller’ or packing between the products and the edges of the display. 
  • Visually expand the volume of products used or display area covered (Ice, like the colour white, tends to create an illusion of space) 
  • Provide decorative impact e.g. carvings, ice mouldings, (jelly moulds etc.), ice blocks, movement (melting ice, ice bags) etc. 
  • To provide a multi-faceted surface for the reflection of display lighting. 

Ice may be supplied from: external sources/deliveries and in-house ice-making equipment. For refrigerated display units the use of ice can prevent slow freezing and ‘sticking’ of products placed in direct contact with refrigerated surfaces. Slow freezing is undesirable as it results in the formation of large ice crystals in the flesh which break down the cell walls and cause leaching of water and nutrient contents upon thawing. Efficient cooling demands that ice be placed over, under and around each product item. 

Products on display must remain visible to the customer. A compromise must be sought when ‘top-icing’ between maintaining product quality and product visibility. In practice, a sprinkling of top ice offers the optimum solution. Un-gutted whole fish should always have their belly regions well-iced since this area is very vulnerable to spoilage and bursting of belly walls. This in turn, results in unsightly fish and contamination of other products.

Care should be taken with large, soft-fleshed, or poorer quality fish to prevent the weight of the flesh or of overlying products from causing crushing and subsequent belly burst. With fish of this nature it may be better to display them on their sides rather than belly-down. 

Gutted whole fish should always be placed belly-down so ice is in contact with the internal body surfaces. This helps efficient drainage of the body cavity and avoids trapped melt water pools, which look unsightly, and harbour bacteria/debris.

The quantity of ice required for display will vary according to the rate at which ice is lost through melting. Factors which can influence this are: 

  • The type of ice used (e.g. flake ice will melt more quickly than other forms) 
  • The design of display unit used (e.g. refrigerated units will require less total ice than non-refrigerated units as they have a lower ice melting rate); enclosed designs will gain less heat from external sources than open-topped designs. 
  • Ambient temperature conditions (e.g. typically less ice will be required in winter or cold temperatures compared with summer or high ambient temperatures). Influencing the ice melting rate will be the location of the display unit in terms of the sun’s aspect, heaters, lights, warm air droughts and other external heat sources 
  • The type and volume of products used for display, such as full display of wet fish products, will require more total ice (initial quantity plus replenishment) than a partial wet fish or mixed product display.

Packaging for Fresh Fish Retailing

Packaging for Fresh Fish Retailing

Food packaging has a lot to contribute in terms of addressing FLW and ensuring food safety as well as enhancing trade and economic development. 

There are several factors which justify packaging fresh fish for retail sale: 

  • protection of the product 
  • ease of distribution and display 
  • provision of fish ready for preparation/consumption 
  • provision of a range of products giving a choice to the consumer 
  • adding value 
  • making the product more attractive 
  • facilitating the provision of information on the product 
  • extending the shelf life

To date, a range of different packaging materials and packaging technologies have been developed to facilitate quality improvement and preservation of packaged foods. Most of the materials are new with improving functions through lamination, coating or incorporating active materials. Key issues to consider with fresh fish packaging used at retail level are: 

  • Gas barrier – for example, modified atmosphere packaging (MAP) requires a high barrier to carbon dioxide (CO2), oxygen (O2) and nitrogen (N2). 
  • Water vapor barrier – impermeability to water vapor is important for fresh fish packaging as its quality is adversely altered by dehydration.  
  • Heat sealability – a tight seal must be formed between the tray and lidding material to prevent contamination and dehydration. Since packaged fresh fish is sold in supermarkets along with other food products, the strong fish odour should not be allowed to spread.  
  • Mechanical damage – expanded polystyrene (PS-E) tray is widely used to protect fresh fish. Sufficient head-space with puncture resistant films like polyamides complete the packaging. 
  • Oil resistance– particularly for fresh fatty fish. 
  • Transparency – the visibility of the product is important to the consumer. Anti-fogging agents reduce condensation on the lidding film. 
  • Drip absorber – fresh fish packaged under modified atmosphere conditions may drip. In order to reduce bacterial growth and provide a clean package interior, absorbent pads are enclosed.  
  • Insulation - important in transport packaging of ice chilled fish. Expanded polystyrene trays are generally used as retail packages.

Three important ways packaging helps to maintain quality and extend shelf life are:

  • Modified Atmosphere Packaging (MAP)
    • The enclosure of fish products (e.g. fresh fish in gas barrier materials where the gas environment has been changed to extend the shelf life and slow down quality deterioration on the refrigerated conditions). The gases used are typically CO2, O2 and N2. CO2 inhibits the growth of many spoilage bacteria. O2 can increase oxidative rancidity, but high levels can maintain the red coloration in tuna and inhibit the conversion of Trimethylamine N-oxide (TMAO) to trimethylamine (TMA), which has strong fishy odour and the characteristic of degrading seafood. N2 is mainly used as a filler gas to replace O2. 
  • Vacuum Packaging
    • Air is removed under vacuum and the package is then sealed. The fish is therefore kept in a low O2 atmosphere, which inhibits the growth of spoilage bacteria as well as oxidative rancidity. The products must be refrigerated/chilled.
  • Active Packaging
    • The addition of active ingredients that absorb or release compound in the gas surrounding the fish. These include oxygen and carbon dioxide scavengers, moisture absorbers and oxygen and carbon dioxide emitters.

Packaging materials should meet a recognized national or global standard such as the BRC/IOP Global Standard for Packaging and Packaging Materials.   

Unfortunately, in some developing countries the small domestic demand for packaging materials leads to low investment by the packaging industry. This in turn limits the ability to capitalize on the benefits of packaging in terms of FLW control. 

Mobile Fish Retailing Technology

Mobile Fish Retailing Technology

In addition to wet fish markets and supermarkets, fish is also retailed to consumers using a variety of transportation, such as bicycle, motorcycle, van, temporary stalls, and small retail facilities. Efforts have been made to improve and investigate the opportunities associated with mobile fish vending or retailing. An FAO review of the marketing of fresh and live fish with examples of low-cost retailing equipment and facilities used in south east Asia also examines the status, problems, and needs of those in the fish retail trade such as the street fish vending sector.

In India, improved technology has been developed and introduced which is designed to improve the quality and workload of mobile fish vendors. Modified rickshaws with retail units on trolleys have been introduced. Vending units have been fabricated using Fibre Reinforced Plastics (FRP), which reduces the weight, requires lesser draft for motion and enhances the ergonomics. The trolley consists of a fish storage chamber, insulated ice box, water tank, and fish dressing deck with wash basin, cutting tool, waste collection chamber and tool box and working space.

India has additionally introduced a subsidy scheme to promote the purchase of motorcycles, auto rickshaws, and insulated trucks which will be used to sell fish. Funding is from the central government under Blue Revolution initiative.

Key Publications

Appropriate Food Packaging Solutions for Developing Countries

The report assesses the state of packaging and packaging technologies in developing countries, with the challenge of global food losses and potential for agri-food systems as the backdrop, and seeks to identify packaging solutions.

On completion of this training programme, trainees will be able to apply basic display and merchandising principles in order to create effective displays of fish and fish products.

Fresh Fish Packaging

Presentation summarizing packaging for fresh fish.

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