`
`Possibilities of
`processing and
`marketing of
`products made from
`Antarctic krill
`
`by
`E. Budzihski
`Deep Sea Fishing Company
`Gdynia, Poland
`P. Bykowski and D. Dutkiewicz
`Gdynia, Poland
`
`
`
`RIMFROST EXHIBIT 1008 page 0002
`
`The designations employed and the presentation
`of material in this publication do not imply the
`expression of any opinion whatsoever on the
`part of the Food and Agriculture Organization
`of the United
`Nations concerning the legal
`status of any country, territory, city or area or
`of its authorities, or concerning the delimitation
`of its frontiers or boundaries.
`
`M-47
`ISBN 92-5-102344-1
`
`All rights reserved. No part of this publication may be reproduced,
`stored in a retrieval system, or transmitted in any form or by any means,
`electronic, mechanical, photocopying or otherwise, without the prior
`permission of the copyright owner. Applications for such permission,
`with a statement of the purpose and extent of the reproduction, should
`be addressed to the Director, Publications Division, Food and Agriculture
`Organization of the United Nations, Via delta Terme di Caracalla, 00100
`Rome, Italy.
`
`FAO 1985
`
`
`
`RIMFROST EXHIBIT 1008 page 0003
`
`PREPARATION OF THIS DOCUMENT
`
`This document has been prepared as part of the FAO's Regular Programme activities
`concerned with the state and prospects of world fisheries.
`The study was designed to
`provide a realistic assessment of the prospects for the future development of the krill
`resources, based on recent technological developments and experiences.
`Through such
`studies, FAO seeks to anticipate developments that might affect the future demand and
`supply of fishery products.
`The authors of the paper worked in consultation with
`Dr. Z. Russek of the Sea Fishery Institute of Gdynia.
`
`ABSTRACT
`
`The potential development of krill has attracted attention
`for several years and has led to the publication of a large num-
`ber of papers.
`Only a few of these, however, (most notably FAO
`reports prepared by Grantham in 1977 and McElroy in 1980) have
`dealt with all aspects of krill development In economic terms,
`from harvesting through processing to marketing.
`Since the
`preparation of the earlier FAO reports, research has introduced
`new elements concerning krill stock estimates and processing
`techniques. The progress made in processes and equipment for the
`production of peeled meat from krill is especially important
`since it indicates that products for human consumption, accept-
`able to the consumer, can be obtained. However, difficulties in
`solving economic and marketing problems still remain and it is
`these that, in the long run, will determine the viability of
`krill development.
`The present study, based on the available literature and
`original analyses, takes into account the limitation resulting
`from the properties of the raw materials and presents the cur-
`rent state of possible commercial-scale uses of krill-proces-
`sing technologies into products for human consumption, animal
`It also outlines views on mar-
`feed and industrial purposes.
`keting problems and provides examples of costs and prices of
`krill products already being produced or expected to be pro-
`duced in the near future.
`
`Distribution:
`
`FAO Fisheries Department
`FAO Regional Fisheries Officers
`Directors of Fisheries
`Selector SM
`Fisheries Management Selector
`Authors
`
`For bibliographic purposes this document
`should be cited as follows;
`
`Budzifiski, E., P. Bykowski and D. Dutkiewicz,
`Possibilities of processing and
`1985
`marketing of products made from
`Antarctic krill.
`FAO Fish. Tech.
`Pap., (268) :46 p.
`
`
`
`RIMFROST EXHIBIT 1008
`
`RIMFROST EXHIBIT 1008 page 0004
`
`page 0004
`
`
`
`RIMFROST EXHIBIT 1008 page 0005
`
`CONTENTS
`
`1.
`
`2.
`
`INTRODUCTION
`
`STOCK ESTIMATES AND CATCHES, FISHING TECHNIQUES AND DAILY CATCH RATES
`
`2.1
`
`2.2
`
`2.3
`
`Stock estimates and catches
`
`Rrill fishing techniques
`Daily catch rates
`
`3.
`
`TECHNOLOGICAL ASPECTS OF KRILL AS RAW MATERIAL
`
`3.1
`
`3.2
`
`3.3
`
`Chemical composition and biochemical properties
`Changes in raw material before processing
`Factors limiting technological usefulness of raw material
`
`4.
`
`ACTUAL POSSIBILITIES OF KRILL PROCESSING
`
`4.1
`
`4.2
`
`4.3
`
`4.4
`
`4.5
`
`4.6
`
`4.7
`
`4.8
`
`4.9
`
`Frozen, boiled-frozen and dried krill
`
`Minced products
`Whole tail meat
`
`Concentrates and other food products
`Krill meal
`
`Chitin and chitosan
`
`Other by-products
`Health aspects of krill products
`Location of processing facilities
`
`5.
`
`ESTIMATES OF PRODUCTION COSTS, PRICES AND DEMAND
`
`5.1
`
`Exploitation option
`
`5.2
`
`Production costs
`
`5.3
`
`Marketing of krill products
`
`6.
`
`7.
`
`CONCLUSIONS
`
`BIBLIOGRAPHY
`
`page
`
`1
`
`1
`
`1
`
`2
`
`3
`
`4
`
`4
`
`8
`
`9
`
`10
`
`10
`
`11
`
`18
`
`18
`
`23
`
`24
`
`24
`
`25
`
`26
`
`31
`
`34
`
`38
`
`39
`
`
`
`RIMFROST EXHIBIT 1008
`
`RIMFROST EXHIBIT 1008 page 0006
`
`page 0006
`
`
`
`RIMFROST EXHIBIT 1008 page 0007
`
`1.
`
`INTRODUCTION
`
`As a result of the search for new sources of animal protein of marine origin and the
`changes In the accessibility of fishing grounds in the 1970s, many states have shown
`increased interest in the possible utilization of Antarctic krill resources on a commercial
`Some of them invested large amounts of money in research and commercial vessels in
`scale.
`the Antarctic as well as in land-based laboratories, engaging specialists in many fields.
`A great number of papers, usually dealing only with some aspects of this large subject,
`have been published.
`Only a few of them dealt with krill development as a whole;
`that is,
`with the technology of krill utilization, the mechanization of processing and the problems
`of economics and marketing.
`Most notable of these were the FAO reports prepared by Granthan
`in 1977 and McElroy in 1980, both of which provided summaries of the accomplishments made
`in this field.
`
`In the period after the publication of the FAO reports, no new ideas in krill utiliza-
`tion were developed.
`However, research projects carried out by many countries have intro-
`duced new elements concerning krill stock estimates and processing techniques. The progress
`made during that period in processes and equipment for the production of peeled meat from
`krill is especially important
`since it indicates that products for human consumption,
`acceptable to the consumer, can be obtained.
`
`However, difficulties in solving problems of krill processing and marketing still
`remain and it is they that, in the long run, will determine the economic viability of krill
`development .
`
`The present study, based on the available literature and original analyses, takes into
`account the limitations resulting from the properties of the raw materials and presents the
`current state of possible commercial-scale uses of krill-process ing technologies into pro-
`ducts for human consumption, animal feed and Industrial purposes.
`It also outlines views
`on marketing problems and on costs and prices of krill products already being produced or
`expected to be produced in the near future.
`
`2.
`
`STOCK ESTIMATES AND CATCHES, FISHING TECHNIQUES AND DAILY CATCH RATES
`
`2.1
`
`Stock estimates and catches
`
`Euphausia superba occurs in the belt of Antarctic waters between the minimum and maxi-
`mum annual range of ice cover, south of the Antarctic Convergence;
`its distribution is
`The distribution of its biomass varies within this vast area.
`cir cumpolar .
`
`Estimates of krill stocks in the Antarctic have varied greatly since 1973, as shown in
`Table 1.
`
`Table 1
`
`Krill Stocks Estimates
`
`Author
`
`Stocks (million tons)
`
`Lyublmova, et al. (1979)
`Marr (1962) as quoted in Everson (1977)
`Marr (1962) and Heyerdahl (1932) as
`quoted in Everson (1977)
`Gulland (1970) as quoted in Everson (1977)
`Doi and Kawamakl (1979)
`
`Voronlna (1983)
`
`Kalinowskl and Witek (1983)
`
`800 - 5 000
`
`44.5
`
`521
`
`750(375)
`
`1 200
`60 - 100
`100 - 400
`
`
`
`RIMFROST EXHIBIT 1008 page 0008
`
`-2-
`
`The disparities In the estimates of the various authors are great, which may be the result
`Still, most authors agree that the stocks are not smal-
`of different calculation methods.
`ler than 100 and not greater than 500 million tons (Kalinowkl and Witek, 1983).
`
`In the 1980s, an international programme of krill research, BIOMASS, was initiated in
`one of its objectives was to assess krill stocks by hydroacoustlc methods.
`the Antarctic;
`This project was based on two experiments, FIBEX and SIBEX.
`The first took place in 1981:
`krill stocks In various sectors of the Antarctic with a total area of 4.54 million kin2 were
`estimated at 78 million tons.
`However, this figure is still being debated by BIOMASS ex-
`If we were to assume that the distribution of krill is uniform and that the whole
`perts.
`area of its occurrence equals 16.2 million km2
`, krill biomass in 1981 in the whole Antarctic
`48 million tons (Kallnowski, 1983).
`would have been 270
`
`The differences in krill stock estimates will most likely persist in the near future.
`Nevertheless, even the most conservative assessment will justify interest in this crusta-
`cean as an Important source of protein of marine origin.
`
`Determining total allowable catch is as controversial as stock assessment.
`The papers
`of Bogdanov and Lyublmova (1978) and some BIOMASS experts state that catching 10 per cent
`of the biomass should not disturb the ecological balance in the Antarctic.
`Mitchell and
`Sandbrook (1980) think that the allowable catch may constitute 2 to 5 per cent of the amount
`of krill at present consumed by whales.
`Gulland (1983) is of the opinion that at least 25
`per cent of the estimated krill biomass may be caught.
`
`To manage the fishery and conserve the living resources of the Antarctic, a Convention
`on the Conservation of Antarctic Marine Living Resources (CCAMLR) was signed in 1980.
`At
`a meeting of representatives of states participating in the Convention In September 1984
`in Hobart, Australia, a group of experts stated that so far there had been no Information
`on the impact of the krill fishery on the size of its biomase.
`However, it was recommended
`that a system of observation and inspection of fleets fishing for krill and Antarctic fish
`be created.
`
`According to the FAO Yearbook of Fishery Statistics, Vol. 54, 1982, world krill catches
`in recent years have been the following:
`
`1975
`1976
`1977
`1978
`1979
`1980
`1981
`1982
`
`39 000 tons
`3 000 tons
`122 000 tons
`142 000 tons
`332 000 tons
`477 000 tons
`448 000 tons
`530 000 tons
`
`In 1983 and 1984, the catches dropped to about 250 000 tons (according to information from
`the CCAMLR session, Hobart, 1984).
`
`2.2
`
`Krill fishing techniques
`
`As is the case with fish, commercial fishing op erat longs for krill are conducted at
`Two types of krill concentrations have been observed:
`the sites of mass concentrations.
`The phenomenon of concentration formation has
`high-density shoals and scattered shoals.
`not been fully explained yet, but it may occur mechanically at the boundary between water
`masses flowing at different speeds.
`
`Like other pelagic animals living In shoals, krill undertake diurnal vertical migra-
`At night, krill patches scatter and move upwards towards the surface.
`During the
`tions.
`The majority of krill
`daytime, krill occur in dense patches below the euphotic zone.
`catches are made in the upper water layer (5-50 m), although shoals are also caught at
`greater depths (100-300 m).
`
`Among the various types of fishing gear tested so far, the most effective was a pela-
`The proper strength of the trawl yarn was
`gic trawl specially designed for this purpose.
`The outer layer is made
`obtained by using a two- layer twine for its belly and codend.
`
`
`
`RIMFROST EXHIBIT 1008 page 0009
`
`-3-
`
`from thick strong twine with a large mesh, the Inner layer from segments of thin yarn with
`a fine mesh.
`Depending on the kind of krill concentration (dense or scattered) , different
`pelagic trawl designs should be used.
`
`The low depths of trawling require the use of short trawling ropes which, together
`with low trawling speeds (2-3 knots), make it difficult to open the trawl horizontally.
`
`Besides improvements in the design of the trawl netting, aimed at increasing its
`strength and reducing trawling resistance, new methods of hauling and emptying krill trawls
`A krill trawling system, consisting of two trawls hauled in parallel,
`are being tested.
`It has been shown that it is possible in this way to reduce energy consump-
`is being tried.
`tion and Increase catch rates (Krepa, 1983).
`
`Krill fishing techniques are generally similar to those for pelagic fish.
`Since krill
`are characterized by low resistance to mechanical damage, large single hauls are of little
`value as the raw material is badly crushed when the trawl is brought aboard. The time of
`its on-board handling becomes longer too.
`The long duration of hauls also results in weight
`Efforts should be made to plan catches in a daily cycle so that single hauls do
`losses.
`not exceed 5-6 tons and processing can be conducted in an unbroken sequence.
`The hydraulic
`pump method for emptying the trawl eliminates crushing during hauling aboard and reduces
`However, this method has not yet been used in practice.
`labour.
`
`Proper hydroacoustic equipment is necessary to plan daily catch rates.
`This not only
`permits the location of krill concentrations and the determination of amounts in the trawl
`but also enables operators to distinguish concentrations of other organisms such as salps
`and jellyfish.
`In practice, planning and controlling daily catches according to the require-
`ments of the throughput of the processing plant is not always possible;
`however, this is
`Experience with
`caused by the differences in yields of daytime and nighttime catches.
`Polish factory trawlers shows that 70-80 per cent of krill are caught during daytime
`(Krepa, 1983), although when krill shoals are scattered the differences between daytime
`Surplus quantities of krill caught during the day
`and nighttime catches are much smaller.
`can be used only for the production of animal feed because of spoilage of the raw material.
`Irregular supplies of raw material to the processing plant may also result from the nature
`of the fishing ground and weather conditions.
`
`The experience gained so far by fishing vessels of various countries, including Poland,
`shows that it is not fishing capabilities that determine the present state and prospects
`for intensification of krill stock exploitation but problems related to processing and mar-
`keting.
`
`2.3
`
`Dally catch rates
`
`Ice around the Antarctic is the main obstacle to fishing operations. It determines
`which on average lasts from mid-November, to mid-April*
`the length of the fishing season,
`It may be extended to seven months or even longer when weather conditions are favourable.
`This has been confirmed by Polish vessels which conducted trials and fishing operations as
`late as the end of Hay.
`
`Many factors influence catch rates, including types of krill concentrations, size of
`vessel and fishing gear, ice and weather conditions, processing capacity of the vessel,
`Catch results of a vessel are best expressed by mean catch
`experience of the crew, etc.
`per day fished, i.e., the size of actual catches during the whole stay on fishing grounds
`In many publications, the daily catch rate was determined on the basis of prac-
`per day.
`This has led to the assumption of mean catch
`tically attainable catch in tons per hour.
`The drawbacks of
`rate per day fished in the whole season at 100-150 tons or even more.
`this method have been noted (Eddie, 1977).
`
`In the present paper, the basis for calculating average daily catch rates was assumed
`to be catch results attained during the 1977 season by three Polish factory trawlers (see
`The results were confirmed by other Polish vessels in the years 1978 to 1983.
`section 5).
`
`These vessels, aided by investigations of fishing grounds by the research vessel,
`PROFESSOR SIEDLECKI, conducted fishing operations in the Atlantic sector of the Antarctic
`
`
`
`RIMFROST EXHIBIT 1008 page 0010
`
`and 90W f near the fishing grounds of South Georgia, South Orkney
`between meridians
`Islands, Graha&Iand and in various parts of the Weddell Sea.
`
`The three vessels caught a total of 8 033 tons of krill during 139 days of fishing,
`Some hauls were as large
`obtaining a daily catch rate of 57,8 tons per vessel (Fig. 1).
`Daily catch rates were sometimes so high that
`as 10-20 tons in 30-60 minutes of trawling.
`fishing operations had to be halted because the tanks and the decks were buried under krill.
`However, such yields were Infrequent and untypical of daily average catch rates per vessel
`Kasprzyk and Szostak, 1981) .
`(Russek,
`
`For the calculation of various variants in the cost of krill processing on board, it
`has been assumed that daily average catch rate equals 55-60 tons and that the vessel remains
`on krill fishing grounds for 126-148 days, of which 106 days fished.
`These values may dif-
`fer only slightly from those currently attained by vessels of other countries.
`This view
`is confirmed by the published cruise results of a large Japanese factory trawler (104.5 m
`it spent 144 and 134 days in the above-
`length) in the 1981/82 and 1982/83 fishing seasons;
`mentioned area of operations, the number of days fished being 115 and 118 respectively. Its
`average daily catch rate was 51.5 tons.
`
`3.
`
`TECHNOLOGICAL ASPECTS OF KRILL AS RAW MATERIAL
`
`It is a truism to say that all technological work should be preceded by the fullest
`Unfortunately, this was not the case in the first
`possible examination of the raw material.
`period of research in krill utilization.
`The fluoride problem may be cited as an example
`here since it hampered the development of technology.
`
`The results of research on the chemical composition and technological properties of
`krill in world literature vary greatly.
`This is especially true as regards labile chemical
`components, such as protein, lipids and vitamins.
`This chapter presents only the results
`of those investigations and views that introduce new elements not included in Grantham's
`report (1977).
`
`3.1
`
`Chemical composition and biochemical properties
`
`3.1.1
`
`Protein, enzymes
`
`No new important findings have been made in this field
`as there has been little re-
`It has been confirmed that fresh krill contains a lot of
`search on fresh raw material.
`The data presented in Table 2 are similar to those obtained by
`water-soluble protein.
`Kolakowski (1982), who determined the share of sarcoplasmatic proteins at 58 per cent of
`the whole, nyofibrillar proteins at 17 per cent, and non-protein (N) at 21 per cent.
`
`The large share of water-soluble protein in krill muscles has serious technological
`during peeling, it is necessary to spray the krill with water.
`This causes
`consequences:
`the extraction of protein from the muscles and, consequently, the lowering of yields.
`Research is being conducted to solve this problem.
`
`Table 2
`
`Amounts of protein in whole fresh krill and tail meat
`
`(Shlbota, 1979)
`
`
`
`uwmuu>< .Hmanna
`Andan—Su:35mauumwbmHowH33—mowuauuwoDanae
`
`vxu
`
`0.:
`
`OCH
`
`RIMFROST EXHIBIT 1008
`
`RIMFROST EXHIBIT 1008 page 0011
`
`page 0011
`
`gC
`
`O
`
`MO
`
`CO
`
`I u
`
`-5-
`
`ff
`
`H (
`
`0
`
`<D
`
`0)
`
`^
`
`0)
`
`i
`
`
`
`RIMFROST EXHIBIT 1008 page 0012
`
`-6-
`
`The main difficulty in krill processing is caused by the very active system of pro-
`During the hydrolysis of casein, they exhibit two wide activity maxima
`teolytic enzymes.
`in the pH range of 6.5-7.5 and 9.3-10.4.
`In the pH range of 6-10. 6 , the activity does not
`drop below 80 per cent of the maximum activity (Galas et al. ; Bobrovskaya, Kardashev and
`The activity of proteases depends on sex, age (size), physiological con-
`Vaitman, 1981).
`dition and feeding.
`All these factors play a role in the processing and storage of krill
`The activity is particularly high in immature specimens, which is explained by
`products.
`intensive metabolism connected with the growth of the animal (Mitskevitch and Mosolov,
`The use of special inhibitors has shown the presence of three types of proteases:
`1981).
`serine proteinases, metal enzymes, and, to a lesser extent, SH-enzymes.
`These types can
`also be found in other invertebrates (Mitskevitch and Mosolov, 1981).
`During cold storage,
`proteolytic activity increases due to the diffusion of enzymes from the intestines to the
`muscular tissue, and the raw material becomes unfit for processing into food products.
`The shelf life of frozen krill at -18C is only three months (Bidenko, Rasulova and
`Odintsov, 1981).
`
`Konagaya (1980) has investigated the distribution of proteases in the krill body. He
`has found that over 95 per cent of protease activity takes place in the cephalothorax
`while the remaining 5 per cent in the tail part.
`That is why it is necessary to remove
`the contents of the cephalothorax by centrifugal action or pressing.
`This will consider-
`ably block autolytic processes in the raw material.
`
`A large role is also played by very active Upases present in the digestive tract of
`krill, which cause the decomposition of phospholiplde and, to a lesser degree, trigly-
`A result of their activity is an increase of free fatty acids (FFA) (Ellingsen
`cerides.
`and Mohr, 1981;
`Galas et al. ,1979). The highest lipolytic activity is exhibited by krill
`with completely filled intestines (Bobrovskaya, Kardashev and Vaitman, 1981),
`
`3.1.2
`
`Lipids
`
`The knowledge concerning krill lipids has grown considerably since Grantham l s report.
`Table 3 presents the results of investigations of lipid contents in krill.
`It was confir-
`med that basic lipid classes include phospholipids and triglycerides as well as sterols
`and their esters.
`An increase in total lipids is accompanied By a drop in the phospho-
`lipid level and a rise in the level of triglycerides.
`There is an almost linear correla-
`tion between the contents of phospholipids and triglycerides and total lipid contents,
`which may mean that both groups play the role of an energy reserve (Ellingsen and Mohr,
`1981).
`
`Table 3
`
`Percentage share of basic classes of krill lipids
`
`(Rzhavskaya, 1981)
`
`x feeding krill
`
`
`
`RIMFROST EXHIBIT 1008 page 0013
`
`The contents of polyunsaturated fatty acids diminish with an increase in total lipid
`This is confirmed by industrial practice.
`contents.
`The generally observed high contents
`of FFA (up to 31 per cent of total lipids) is, according to Ellingsen and Mohr (1981), a
`result of lipase and phospholipase activity.
`These enzymes continue to be active in raw
`material frozen at excessively low temperatures.
`According to these authors, the natural
`level of FFA in krlll is about 4 per cent.
`
`The presence of waxes was also observed in Euphausia superba (Sawicki, 1979;
`Ryhalkina et al . , 1981; Saether, Ellingsen and Mohr, 1983).
`These compounds are charac-
`teristic of Euphausia crystallorophias living farther south.
`Lipids concentrations in
`krill increase with age; after spawning, they rapidly decrease.
`Almost 70 per cent of
`lipids are located in membranes under the shell (Bidenko, Rasulova and Odintsov, 1981).
`
`3.1.3
`
`Fluoride problem
`
`Table 4
`Concentration of fluoride in Antarctic animals
`
`
`
`RIMFROST EXHIBIT 1008 page 0014
`
`The paper published by Soevik and Braekkan In 1279 had a considerable impact on ear-
`lier opinions concerning the possible uses of krill for human consumption and animal feed.
`Determining fluoride contents in the whole krill Cup to 2 400 ppm) and its anatomical parts
`at a very high level, these authors stated that: "This would make krill in any form, even
`peeled, fail to comply with requirements for human consumption. 11
`
`Numerous publications have since confirmed the high contents of fluoride in krill,
`even when compared with other animals from the Antarctic (Table A) .
`The papers of
`Christians and Leinemann (19.80) and Christians, Leinemann and Hanthey (1981) played a major
`They proved that fluoride migrates from the shell to the
`role in explaining this problem.
`The lowering of temperature
`muscle in frozen krill.
`to -40 C stops this process.
`By pre-
`viously separating body fluids, the migration of fluoride during the frozen storage period
`Similarly, boiling of the raw material arrests the migration.
`may be reduced.
`
`During the fifth Polish Antarctic expedition on the research vessel, PROFESSOR
`SIEDLECKI, in 1981, the pleon muscle of freshly caught krill was shown to contain about
`A linear correlation between the contents of the shell and fluoride
`40 ppm F (dry weight).
`was also established.
`The assertion that over 90 per cent of fluoride are contained in
`A technique for the pro-
`the chitinous-mineral shell guided technological investigations.
`duction of meal with reduced shell contents was worked out and those for obtaining meat by
`the roller method and mince improved (Christians, Leinemann and Manthey, 1982; Bykowski,
`1982) .
`
`However, the fluoride problem remains of interest to both biologists and technolo-
`The mechanism of its binding in the shell has not been fully explained, although
`gists.
`it is associated with frequent moults of this crustacean (Bucholz, 1982).
`There are no
`papers on the reminerallzation of fluoride from the exuvia and dead animals or on the path-
`way of fluoride in the Antarctic food chain.
`
`3.2
`
`Changes in raw material before processing
`
`The total number of bacteria in krill Immediately after capture is very low, not
`exceeding several hundred to several thousand per gramme (Kelly, Lukaschevsky and
`Therefore, the rapid changes in freshly
`Anderson, 1978; Ganowlak, 1979; Kartlntsev, 1981).
`caught krill are not of a microbiological character.
`
`Immediately after death, interrelated biochemical changes take place, thus reducing
`These include autolysis, which results in drip and un-
`krill f s quality for processing.
`Rigor mortis under average
`pleasant odour, as well as changes in texture and colour.
`temperature conditions of the area (0-5C) begins after one hour and lasts for two more.
`Freshly caught krill are brick red-pink to pink.
`Through the almost transparent shell,
`It is possible to see the green or colourless patch of the stomach.
`In the first two
`The shell becomes
`hours, krill become non- transparent, starting with the cephalo thorax.
`After 4-6 hours, the colour turns light
`shiny, the tail arched in a characteristic way.
`pink, then light grey and the Intestines become dark.
`Yellow-green fluid starts to drip
`from under the shell.
`
`Longer storage causes flaccidity of the tissue, which becomes clammy; the shell is
`The main factor
`After 12-16 hours, the bacterial decomposition of tissue begins.
`grey.
`in those changes is the above-mentioned complex of proteases, concentrated in the cephalo-
`Unpleasant odour is also a result of enzymatic changes in phytoplankton, during
`thorax.
`which, among others, dimethyl sulfide is formed.
`
`Blackening of the cephalothorax was earlier ascribed to the activity of tyrosinase,
`At present, this process is believed to be caused
`as is the case with other crustaceans.
`by catechol oxidase (Oshlma and Nagayama, 1980).
`
`have shown that
`taste, odour, texture
`Sensory investigations of general quality
`after 3-4 hours of storage at air temperature the intensity of those changes reaches such
`a level that the raw material is no longer fit for processing into food (Kolodziejski e
`Smirnov, Boydalinova and Andreev, 1981> Andreev, Bykov and Smirnov, 1981).
`al., 1979;
`
`
`
`RIMFROST EXHIBIT 1008 page 0015
`
`-9-
`
`The Intensity and progress of these changes depend mainly on two factors.
`Soviet
`scientists have proved that the raw material coming from large (10-15 tons) and long
`(1.5 hours) hauls has a much higher level of volatile bases after 3-4 hours of storage
`than that from small (up to 5 tons) and short (1 hour) hauls (Artiukhova and Kapitanova,
`With controlled hauls, this factor plays a much smaller role than the storage
`1981).
`method before processing.
`
`In commercial practice, two methods of storage are employed: "dry" storage on board
`or in tanks and in Refrigerated Sea Water (RSW) or seawater.
`The first method results in
`large amounts of drip as the delicate raw material is mechanically compressed, and a large
`loss of dry weight, including valuable components like protein.
`On the other hand, storage
`in RSW causes a strong extraction of water-soluble protein and the rise of salt contents.
`The amount of NaCl in krill doubles after four hours (Schreiber et al. t 1981) .
`The only
`advantage to this method is that it makes unloading from tanks easier and that the raw
`material does not lump so much.
`
`In practice, the raw material is more frequently ^stored "dry 11 on board, often in
`When krill density is about 0.9 t/m , a
`layers of 50 cm.
`10 tons stored in 20 cm
`haul^of
`layers, which would avoid damage, would occupy an area of 55 m .
`This is not feasible on
`fishing vessels currently used.
`
`A better understanding of the changes that take place in the raw material allowed a
`more precise formulation of storage principles.
`Storage time should be as short as pos-
`for krill for human consumption, It cannot exceed 3-4 hours; for krill for meal
`sible;
`production, 8-10 hours.
`To keep within these deadlines, fishing techniques must allow for
`an adjustment of the haul size and the vessel must be properly equipped for processing,
`i.e., conveyor belts to shorten the passage of the raw material and tanks.
`
`3.3
`
`Factors limiting technological usefulness of raw material
`
`3.3.1
`
`Size
`
`Because of the high proteolytic activity, immature krill of a length of about 34 mm
`Their shelf life at -18C is only one month when they are to be used
`should not be frozen.
`That IB why hauls consisting of 40 per cent of such specimens are used
`in food production.
`for the production of krill meal (Bobrovskaya, Kardashev and Vaitman, 1981).
`
`When krill of 35-46 mm and larger
`The share of tail meat in krill changes with size.
`are peeled manually, the yield of meat increases from 25 to 32 per cent (Bidenko, Rasulova
`A similar relationship was observed during mechanical krill peeling
`and Odintsov, 1981).
`When producing canned products from the coagulated paste
`(Bykowski and Dutkiewicz, 1984).
`, the quality of the product was lower when small krill (up to 35 mm in length) were
`"Ocean 11
`After defrosting, the drip is much smaller in
`used (Artiukhova and Kapitanova, 1981).
`large krill than in small ones (Suzuki, 1981).
`
`The problem of mechanical sorting of krill has not yet been solved, and grading trials
`A question arises as to how to determine the size of krill so they
`have ended in failure.
`Fast methods of approximate size measurements, which are based
`can be utilized properly.
`on the correlation between the length and the volume of specimens, have been worked out
`Bidenko, Rasulova and Odintsov, 1981).
`(Kolodziejski et al^, 1979;
`
`3.3.2
`
`Amount of phytoplankton
`
`Krill feed on phytoplankton, which is accumulated in the thoracic basket and the
`Phytoplankton is responsible for the colouration of the head section and
`digestive tract.
`Inten-
`cephalothorax and the deterioration of the sensory properties of the raw product.
`sively feeding "green" krill are unfit for processing into mince-type products (Bykov,
`Because of the chlorophyll contained in phytoplankton, the coagulated paste Ocean
`1981).
`Canned products made from feeding krill are of inferior
`was green to grey in colour.
`In Poland, on the basis of size and feeding
`quality (Artiukhova and Kapitanova, 1981).
`conditions, three grades of krill, varying in technological usefulness, are distinguished
`(Table 5).
`
`
`
`RIMFROST EXHIBIT 1008 page 0016
`
`-10-
`
`Table 5
`
`Technological usefulness of krill depending on feeding
`condition and size (Kolodziejskl et al.,1979)
`
`3.3.3
`
`Gut removal
`
`The processing of krill with intestines and their contents causes a deterioration in
`the quality of products and may lead to disqualification.
`Gut removal is now believed to
`be necessary for processing krill into mince-type products.
`It may be accomplished either
`by centrifugal action or by gentle pressing.
`The result of both methods is similar, i.e.,
`the gut and phytoplankton are removed.
`In addition, fat contents are reduced by about
`30-40 per cent, which is desirable in certain technologies.
`The effectiveness of gut
`removal can be seen from the considerable reduction of enzymatic activity in the raw
`material (Kolodziejski, 1979).
`
`3.3.4
`
`By-catch problem
`
`Krill processing is made more difficult by the presence of by-catch (salps, jellyfish,
`juvenile fish, fish larvae) , which often constitutes over 20 per cent of the total catch
`When processing krill into food products, it is therefore necessary to separate
`in a haul.
`the by-catch manually and, in extreme cases, change the fishing ground.
`
`4.
`
`ACTUAL POSSIBILITIES OF KRILL PROCESSING
`
`4.1
`
`Frozen, boiled-frozen and dried krill
`
`With the exception of Asian markets, the prospects for the sale of frozen or boiled-
`frozen krill are not very promising.
`Nevertheless, such products were successfully mark-
`eted in the USSR as feed for fur animals.
`Only krill store