Ice & refrigeration

"The faster we ice, the higher the price". As with all the sayings you can hear along the quays of Atlantic fishing harbours, the above-mentioned formula relies on a great deal of commonsense and experience.

More technical and even scientific analysis would highlight the reasons for this observation made by fishermen who want to sell their catch to demanding customers.

Fish starts to spoil the moment it is in the net. However, bacterial growth may be significantly reduced and almost stopped if the fish are cooled right away and maintained around 0 degrees centi­grade. Bacteriological research shows that it is possible to extend drastically the usual shelf life of fish. For some species the life can be multiplied by ten.

Icing

Ice is an ideal cooling medium for fish. Its cooling potential is almost 80 times more than for the same quantity of chilled wafer. Ice absorbs the heat of the fish when it changes its state, that is to say when it melts. It thus maintains the fish near the 0 degrees centigrade level. This temperature is ideal for such a fragile product which could be superficially frozen and burnt at lower temperatures. While cold air ventilation would dry the fish up, the melt water from the ice keeps it moist and glossy.

The speed of cooling must be kept as high as possible. In the work of heat ex­change, the heat exchange surface is the governing factor for the speed of cool­ing. Small ice in thin pieces will provide a broader heat exchange surface and there­fore it will cool the fish faster. From this point of view flake-ice, with a thickness of 2 mm approx, is the most efficient among all kinds of ice.

Because it is dry and sub-cooled, flake-ice packs well and does not damage the surface of the fish. It is a real time saver when it comes to boxing, whether onboard or on-land.

Boxing

The choice of a strong and clean box is another step towards quality. The required amount of flake-ice will cover the bottom of the box without occupying much space. The gutted fish can then be laid-out on this ice with bellies down al­lowing drainage from the gut cavity. Boxes will be piled up in stacks. They should not be over-filled, as this could cause excessive pressure on the fish in the lower boxes. Holes on the sides and bottom of the boxes allow for drainage at the melt wa­ter to avoid any contamination of the fish. For a uniform temperature of the fish inside the boxes, the crew will ice top and bottom with a layer of the flat flake-ice in the middle. If the box is uncompleted with fish, it will still be topped with ice.

Ice Dispenser

During storage and handling, ice can only deteriorate and get polluted. With the Geneglace Orbital Silo, the flake-ice is stored in a well-insu­lated, food compat­ible bin. An auto­mated mechanism with extraction auger delivers the ice on demand by simply operating an on/off switch. This new device makes the boxing task a lot easier and faster.

Exercise 2. Answer the following questions:

1. What does the saying "The faster we ice, the higher the price" rely on?

2. When do fish start to spoil?

3. How can bacterial growth be reduced?

4. Is it possible to extend the usual shelf life of fish?

5. What is an ideal cooling medium for fish?

6. What type of ice will provide a broader heat exchange surface?

7. What kind of ice is the most efficient?

8. How must fish be packed in boxes?

9. What should be done to keep a uniform temperature?

10. How ice is transported to the fish processors?

Exercise 3. a) Write down a detailed plan of the text.

b) Speak about icing of fish and its benefits.

TEXT 5

Exercise 1. Read and translate the text with the help of a dictionary.