Turkey (Contd.):

About 25,000 persons are employed in the Turkish fishing industries, including canneries, reduction plants, etc.

The export of fish--including fresh and frozen fish, smoked and canned fish, fish meal and fish oil, and sponges, etc.--has increased considerably.

The annual per capita consumption of fish--including processed fishery products--has increased to 3.5 kg. (7.7 lbs.) in 1957 as compared with 2.5 kg. (5.5 lbs.) in 1952. (FAO General Fisheries Council for the Mediterranean, Information Bulletin, No. 14, Aug. 1958.)

U.S.S.R.

RUSSIAN METHODS FOR FREEZING FISH-AT-SEA:

The development of efficient fish-freezing-at-sea methods, and the construction of appropriate installations to effect this, are two of the most important problems facing the fishing industry, the British fishery periodical, The Fishing News of Sept. 26, 1958, reports in a summary of a paper presented by Soviet fisheries experts at a meeting held in Moscow.

These problems have been studied in Russia since 1888 when barges were constructed for frozen fish, and today about 300 large refrigerated fishing vessels are operated in the U.S.S.R. These vessels include refrigerated floating factories, non-powered floating refrigerators and fishfreezing barges, fishing freezer vessels of the Druzhba class, and large freezer trawlers.

Freezing in brine is used on some of these, with airblast installations on others, including the freezer trawlers of the Pushkin class.

In the former case, sometimes the fish are dipped in cold brine, and sometimes it is sprayed over the fish. Various types of conveyors are used, some having automatically unloading baskets, others a wire-mesh conveyor belt carrying fish through the brine spray.

Most of the vessels (as distinct from the floating factories) are, however, equipped with tunnel freezers of the parallel air-blast type. The air coolers are located in the bottom of the tunnel on the factoryships, and beside it on the trawlers. The upper part of the tunnel has an overhead rail with a chain conveyor transporting the baskets of fish, which are in the tunnel from 4-5 hours according to size.

Aboard the trawlers, after unloading on to the upper deck, the fish is delivered through a bunker on to a table where six men are working. Each guts seven fish per minute by hand, so that about 60-65 tons of fish are dressed on the table each 24 hours. The gutted fish are placed on one of two conveyors, one leading to the fillet production line, the other for freezing drawn cod in blocks.

Machines are used on the filleting line for heading, filleting, and skinning, the filleting machine having an output of 20 fish per minute. Production of unskinned fillets is 42 percent of the whole fish, of the skinned 37.7 percent. The fillets are washed in brine, packed into pans, the pans loaded into trucks and run into the freezing tunnel. Eventually the fillets are taken from the pans and glazed with a water spray. The blocks are then cartoned, weighed and marked, and stacked in the hold.

There are four blast tunnels, each taking four trucks containing about 1,100 pounds of fish each.

Cod less than about 20 inches long are frozen in the round in blocks. After gutting and heading, the fish are washed in a special machine and placed in pans holding about 20 pounds, after which the freezing follows the same process as above described. The output in this section is about 35 fish per minute or 50 tons in 24 hours.

Comparative figures which have been produced show that the most perfect freezing installations are those operating on the large refrigerating freezer trawlers and some of the floating factories.

Even these, however, have certain faults which have yet to be eliminated: for instance the uneven distribution of the air current in the tunnel causing a variation in the freezing of the fish; and the mechanization of the installations still leaves much to be desired. Although baskets in the tunnel freezer in some of the floating factories are moved by means of a chain conveyor, as they leave the tunnel they must be transported manually. The heavy and bulky pneumatic machine used in moving the baskets containing the fish on the freezer-trawlers also needs simplification.

In all cases the use of removable pans to hold fish is considered a drawback. They are subject to damage, and floor space is taken up in their cleaning, repair and storage. In this connection a new method was evolved last year by the U.S.S.R. Scientific Research Institute for Refrigeration, whereby these faults were eliminated. In some cases defrosting the coils and the draining of the melted ice caused some trouble which needs investigation.

Those installations, including the trawlers, where the pans are provided with covers, give better results than where the pans are open. The covers reduce shrinkage (0.32 to 1.41 percent, reduced to 0.15 when covers are used), heat exchange conditions are improved, the upper surface of the block flattened, and its volume thereby reduced.

Because of drawbacks found in the process no more freezing-in-brine installations are being used in the U.S.S.R. except for tuna fishing. It has been found that the surface of the fish is salted, there is a great difficulty in maintaining the necessary temperature, and the working conditions for the personnel are unsatisfactory as they are in constant contact with cold brine.

However, the process has certain advantages, so research is continuing on the lines of finding an osmotically passive solution with a sufficiently low freezing temperature, so that the method could be used satisfactorily on some vessels.

Research on a large scale is also proceeding in the Soviet Union on methods of freezing by heat transfer by direct contact of the fish with the cooling surfaces--intermediate media, air and brine all being eliminated. Some experiments along these lines include a compression of the blocks which greatly increases the hold capacity. An experimental rotary quick freezer of this type has movable hollow wall moulds from which the frozen fish block can be removed without defrosting and the block is discharged automatically from the freezer. This work appears to be most promising.

United Kingdom

CANNED SALMON IMPORTS
INCREASE SHARPLY WITH
LIFTING OF RESTRICTIONS:

Japanese salmon canners are to expand exports to the United Kingdom to 836,000 cases by the end of the year, an increase of 300,000 cases as compared with last year's figure, according to a September 29 report from Tokyo.

The decision was made in an attempt to meet possible increased demands from Britain following the recent easing of import restrictions.

United Kingdom (Contd.):

First arrivals of canned salmon since the lifting of British restrictions on dollar imports are expected towards the end of November.

It is expected that the price to the consumer for some grades of salmon will be about 4s. 6d. a pound can (about 63 U. S. cents, and maybe much lower in the larger cut-price shops.

The free import of Canadian salmon is welcomed by the wholesalers who feel that the end of the artificial market for canned salmon is in sight. In the past some firms, including caterers, have been willing to pay exorbitant prices, but the bottom has now been knocked out of this market. The resale market has already felt the impact and at the time of writing the price per case of 48 half-pound cans had dropped by £2 (US$5.60).

Canned salmon sold heavily in the industrial areas before the last war, which soon made it a "luxury" food. Liverpool handles most of the imports and it seems likely that the bulk of the trade will revert to the well-known prewar brand names. (London Financial Times, September 30, 1958.)

EXPERIMENTS ON

TEMPERATURE OF FISH IN TRANSIT:

Tests to determine the temperature of fish while in transit from the point of landing to the inland point of destination were conducted in June 1958 by the Humber Laboratory, Hull, British Department of Scientific and Industrial Research. These tests were part of a series of studies on the temperature of fish at all stages of the distribution chain begun in 1956.

Two observers were stationed at Aberdeen, two at Lowestoft, and two at an inland depot at Wokingham. Those at the ports measured the temperature of the fish as it was packed into boxes and marked such boxes with a special label. These boxes then traveled with all the rest of the consignment by insulated trucks to the inland depot.

Here the other observers watched for them during unloading and measured the fish temperatures again. Finally, some of the boxes which had traveled from Aberdeen to Wokingham were sent on to Lowestoft to simulate the journey from the inland depot to the retailer, and the fish temperatures measured for a third time.

While all this was going on, other members of the Humber Laboratory staff remaining in Hull measured the temperatures of herring arriving there from Scotland in boxes on open trucks covered by tarpaulins.

This work was not simply a comparison between insulated and uninsulated trucks. That was only one of the differences. An important point which was noticed right at the beginning of the experiment was that the fish in insulated trucks was

always very well iced. That is to say, not only was there plenty of ice in each box, but it had been put in the right places, namely, both at the top and the bottom, as recommended.

Fillets, which at the time of packing in Aberdeen were at temperatures of 41 to 45 F., arrived at Wokingham at between 32° F. and 32.5 F. These are the average temperatures for the "best" and "worst'' days, readings being taken for four days in succession.

Even when some of these boxes had been transferred from one truck to another and made the further journey to Lowestoft, their temperatures were between 33 F. and 35 F. Similarly, cod fillets, which left Lowestoft at 44°F. 46° F., arrived at Wokingham at 32° F.-33° F. In all cases the temperature of a box was obtained by taking the average of 12 temperatures measured in the fish.

Herring are slightly more difficult to cool than white fish, and although the average temperature of herring at Aberdeen varied between 37 F. and 42 F., i.e., lower than that of fillets, the average temperature of herring at Wokingham was a little higher--32 F. to 34 F. The difference, however, is very small. In all cases, for both herring and white fish, there was ice left in the boxes on arrival.

Many readings for other types of fish were also obtained and these results were all very close to those already given. In all, some 5,000 temperature measurements were made.

First of all there is no doubt that the fish had a good start on their journey. Herring, at a temperature of 37° F.42 F., suggest icing at sea as well as icing and quick handling on the market. More recent observations at another port have shown that it is quite possible for a drifter to land herring with an average temperature of 50° F.

The temperature of the fillets at the start of their journey was also somewhat below the usual of about 50° F. A freshly-cut fillet tends to be at a temperature very close to that of the water used in filleting, and it is not easy in practice to keep this much below 50° F. even with the use of ice.

Thys with the present methods of the trade a temperature of 40° F.-50° F. in this stage of distribution is considered inevitable. The important thing is to get the temperature of the fillets down to 32° F. again as quickly as possible.

O

The most notable feature was the temperature at the end of the journey. These were very close indeed to the ideal figure of 32 F. In fact, some of them were slightly below this, for although pure ice melts at 32 F., a mixture of fish and ice can reach a slightly lower temperature (without freezing) because of the small amount of salt in the fish. Thus, although 32° F. is the ideal to aim at for wet fish, it is possible to do perhaps 1° F. better.

These results in this specialized distribution system may be compared with those obtained for herring arriving in Hull on open trucks under tarpaulins. When the latter were removed and the boxes unloaded it was found that 4 boxes out of 5 had no ice in them at all, and that the fifth only had one or two pieces.

As would be expected, the temperatures of the fish varied a great deal and although there were a couple of readings of 33 F. there were also several of 53°F. The over-all average of 900 readings on 32 boxes was 46.5° F. and only 5 percent of the fish were below 40° F.

Now the reason for these high temperatures is not necessarily the absence of insulation, although this will certainly be a contributory factor. More important still is the use of enough ice in the right place. The purpose of using ice is firstly to cool fish down, and secondly to stop it warming up again.

The amount of ice needed to cool the fish depends simply on the weight of fish and its temperature and has nothing to do with insulation. The rate at which the fish cools down depends on the way the ice is distributed. Where insulation matters is that it affects the amount of ice needed to keep the fish cool on the journey.

Within limits the more insulation the less ice. The man who uses open trucks would get as good a result as the man with insulated ones, but he would need to use more ice to do it. But as far as DSIR experience goes, the reverse seems usually to be the case.

United Kingdom (Contd.):

The same sort of argument applies if one is considering what thickness of insulation should be used. For any particular journey it should be possible to strike a balance between the cost of insulation and the cost of ice, oearing in mind that we have to consider not only the cost of these materials themselves but their effect on the payload of the truck.

However, as far as wet fish is concerned, there is a certain minimum amount of ice that we must have anyway, and if this ice is not distributed in the right places, no amount of insulation will give good results.

Of course, temperature is not the only thing that affects the quality of fish, and even the best distribution system cannot make fish any better than it was when it was landed. What it can do is to minimize the deterioration that inevitably occurs between the wharf and the retailer. In this respect there is much too big a difference between the best and the average. From Fish Trades Gazette (August 30, 1958), a British fishery periodical.

Note: Also see Commercial Fisheries Review, July 1958, p. 67.

SMALL FISH MEAL
PLANT DEVELOPED:

An engineering firm of Hull, England, has developed an interesting range of small fish meal plants, which are sufficiently compact to be installed aboard ship or in other confined spaces and are also claimed to be entirely self-contained.

The plants are designed for the production of meal and oil from fish and fish offal, shellfish, abattoir, and industrial waste products. It is particularly designed for service in isolated areas and has its own power unit, a 60 hp. gas turbine whose exhaust gases provide heat for cooking and drying.

The standard unit in the range is claimed to be suitable for all types of gutted or ungutted fish and has a nominalı fish or fish waste capacity of up to 2,000 pounds an hour and 1,500 pounds an

hour for shellfish or shellfish waste. A smaller plant has a capacity of 1,000 pounds an hour for fish or fish waste.

The working of the plant is described as follows: "The raw fish or waste is fed to the scraper elevator which discharges to the hogger, a machine specially designed for the reduction of fish, offal, and similar materials. From the hogger, the reduced material falls into a twin screw metering bin which feeds the cooker with a steady, continuous flow of raw material at a predetermined rate. "The cooker is a horizontal tubular vessel fitted with a jacket through which a proportion of the hot gases from the gas turbine are circulated. A special form of screw conveys the material through the cooker.

"The cooked fish or offal is then light

ly pressed in the new design, screw con

veyor-press, which removes a proportion of the free liquors. The press discharges through a magnetic separator to a combined dryer and grinder where the turbine exhaust gases are introduced to provide latent heat. The time in the dryergrinder is about three seconds.

"The dried meal is drawn through a cyclone separator and cooled in a further cyclone system which incorporates an adjustable cooling air intake and rotary valve discharge.

The standard fish-meal unit has a gross weight of just over 30,000 pounds and measures 21 feet long, 7 feet wide, and 10 feet high. (The South African Shipping News and Fishing Industry Review, August 1958.)

.(US$1,000).

13,598 239 251

1,837

3

333 16 14,440