a recent review article,” health benefits attributed to
`astaxanthin included reduced risk of cataracts, diabetes,
`heart disease, neural deterioration, and certain cancers;
`however, most of these studies were conducted using in
`vitro or animal models. In a human trial, young adult
`male volunteers provided astaxanthin in a daily beverage
`for 14 d showed protection against premature LDL oxi-
`dation in the absence of any other dietary changes.“
`Despite the promising results for astaxanthin, research is
`needed regarding the health benefits of astaxanthin de-
`. rived from krill.
`
`One of the most important antioxidants is vitamin E,
`which functions specifically to protect against lipid per-
`oxidation in biological membranes. Due to methodolog-
`ical difficulties, vitamin E has not been determined
`extensively in foods. According to Table 2, krill meets
`the RDA for vitamin E and contains higher amounts of
`vitamin E than either shrimp or fish. Thus, the stability of
`krill may be attributed to its high levels of vitamin E.
`However, other components may also protect krill from
`oxidation. Dunlap et al.35 identified a marine-derived
`tocopherol with enhanced antioxidant effects on cellular
`lipids. Venkatraman et al.36 reported that mice fed a diet
`containing 10% krill oil had higher liver expression of
`endogenous antioxidant enzymes (i.e., catalase, glutathi-
`one peroxidase, and superoxide dismutase) and lower
`peroxide and thiobarbituric acid values compared with
`mice fed a 10% corn oil diet. The high content of vitamin
`E and the presence of other antioxidant components
`suggest
`that krill may have beneficial effects against
`oxidative damage.
`The water-soluble vitamins play an important role in
`maintaining health by acting as coenzymes in energy
`metabolism. Table 2 shows the levels of selected water-
`
`soluble vitamins in krill, shrimp, and fish, along with the
`RDA for these vitamins in adults. The levels of thiamin,
`
`riboflavin, and niacin are higher in fish compared with
`shellfish (i.e., krill and shrimp), but are below the RDA
`for adults, indicating that in general seafood is a poor
`source of these vitamins. Table 2 also shows the levels of
`
`the B-complex vitamins B12, B6, and folate in krill,
`shrimp, and fish. These vitamins play a role in the
`metabolism of homocysteine, so deficiencies can lead to
`high blood homocysteine. This has important implica-
`tions because a high blood level of homocysteine is an
`independent predictor of heart disease and stroke.” The
`vitamin B6 content of most seafood is below the RDA,
`and levels in krill are below that of either shrimp or fish.
`Although krill is higher in folate than shrimp and fish,
`levels are still below the RDA. On the other hand,
`
`vitamin B12 in krill (16 p.g/ 100 g) is substantially higher
`than in shrimp (1.16 p.g/100g) or fish (4.17 to 4.45
`ug/100g) and exceeds the RDA of 2.4 p.g/d for adults.
`
`The assessment of the nutritive value of krill based on
`
`vitamin content indicates that it has considerable appeal
`for human consumption because it provides a good
`source of vitamin B12, vitamin E, and astaxanthin, as
`well as other potential antioxidant compounds.
`
`KRILL PROTEIN QUALITY
`
`Whole Krill
`
`Krill is a high-protein food, having a protein content
`estimated in the range of 60% to 65% dry weight.8
`Similar to other animal foods, the protein derived from
`krill is a complete protein, as indicated by the presence of
`all nine of the indispensable amino acids required by
`adults. As shown in Table 3,38 the level of all of the
`indispensable amino acids in whole krill met the FAO/
`WHO/UNU amino acid requirement for adults” (with
`the exception of histidine). In contrast, several indispens-
`able amino acids in fish were below the amino acid
`
`requirement for adults, most notably methionine and
`cysteine. However, it should be noted that the indispens-
`able amino acid levels in whole krill were below the
`
`reference protein, egg. Tamura4° reported an amino acid
`score in the range of 0.85 to 1.00, indicating that the
`amount of indispensable amino acid provided by krill
`protein met the protein requirement of adults. Although
`considered a high-quality protein, krill is of lower quality
`than whole egg, which has an amino acid score of 1.21.
`In practice, protein quality is determined not only by
`the amino acid composition but also by its digestibility.
`Iwantani et al.“ fed rats a diet containing either egg
`protein or defatted, freeze-dried whole krill for 4 weeks,
`and then determined the weight gain of the animals to
`calculate the protein efficiency ratio. Biological value
`and net protein utilization were also measured to assess
`protein availability and digestibility. Rats fed whole krill
`gained less weight, had a reduced protein efficiency
`ratio, biological value, and net protein utilization com-
`pared with animals fed egg protein. The decreased di-
`gestibility of krill protein may have been due to the
`presence of the exoskeleton. Obatakezz determined the
`nutritive value of the protein in krill meat after removal
`of the exoskeleton, and found that it was still inferior to
`
`that of egg protein. Findings in the animal studies were
`not always indicative of the findings in humans. In a
`human trial, Tamura42 fed boiled krill or whole egg to
`adult men for 21 days and reported a net protein utiliza-
`tion of 55% for krill and 61% for whole egg, with no
`differences in their digestibility. Based on the evidence,
`krill appears to be a good source of high-quality protein.
`The large biomass and high-quality protein offered by
`krill provides an economical replacement for commer-
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`Table 3. Amino Acid Composition of Krill and Lean (Trout) and Fatty (Salmon)
`e Amino Acid Re uirement for Adults
`Fish* Compared With Egg, Alon With th
`S
`E
`Re
`'
`Amino’Acid
`T Krill
`Trout
`almon_L __gg_
`uirement
`
`mg/
`
`Isoleucine
`25
`9.4
`10.0
`‘:63
`19
`Leucine
`40
`16.6
`17.6
`88
`
`Methionine +
`
`24
`
`8.3
`
`14.9
`
`8.7
`
`56
`
`15.7 ‘i’ 98
`
`17
`
`19
`
`__l
`
`9
`2.3
`10.5
`6
`
`9.5
`2.4
`.1 1.1
`6.4
`
`16
`72
`24
`
`5
`13
`
`1T A
`
`cysteine
`__i
`
`
`Phenylalanine +
`50
`
`
`
`
`osine
`Threonine
`Trymphan
`Valine
`Histidine
`
`
`
`
`
`7
`26
`1 1
`
`
`
`sartic acid
`
`53
`
`21
`
`22.1
`
`47.6
`
`ND
`
`Glutamine
`
`67 EED
`
`ND
`15.9
`10.4
`9.8
`34
`Glycine
`ND
`18.9
`7.6
`7.2
`23
`Proline
`ND
`35.2
`8.8
`8.4
`19
`Serine
`* Whole krill (Euphausia superba), wild rainbow trout (Salmo gairdnerz‘ Richardson),
`and wild Coho salmon (Oncorhynchus kisutch). Values for krill are based on Torres et
`al.3; values for trout, salmon, and egg are based on the USDA"); values for egg are also
`based on Young and Pellettas; requirement for adults based on FAO/WHO/UNU.”
`ND, Not determined.
`
`cially available protein sources. In addition, commercial
`protein sources available for human consumption such as
`casein, whey, soy protein, lactoalbumin, and wheat glu-
`ten have various limitations. For example, casein is low
`in sulfur amino acids, particularly cysteine, which must
`be added to the diet. Products in which krill protein may
`substitute for other proteins are nutritional supplements,
`sports drinks, infant formulas, and milk replacers. For
`these products, protein concentrates rather than whole
`krill or krill meat are used.
`
`Krill Protein Concentrate
`
`Protein concentrates are produced by technologies
`that concentrate the proteins in food so that levels are
`higher than those in the original food, making them an
`inexpensive source of available protein. Preparation of
`protein concentrate from fish is accomplished by extract-
`ing the lipids, removing the bones, and ‘drying, so that the
`resultant product is 85% to 95% higher in protein than
`the original fish. Lack of proper technology for protein
`recovery from krill has hindered progress in the com-
`mercial development of krill protein concentrates. Some
`research has been carried out that made use of kri1l’s high
`
`content of proteolytic enzymes to produce a product with
`protein recovery as high as 80%.“ There is technology
`available for isolating muscle protein in a continuous
`
`mode from whole krill to produce krill protein concen-
`trate. The continuous protein recovery technology is
`based on a principle of isoelectric solubilization followed
`by isolelectric precipitation of the protein. This basic
`biochemical principle has long been used in the dairy
`industry to manufacture cottage cheese, and also in other
`food processing industries such as those for soy protein
`isolates and concentrates. More recently, the principle of
`isoelectric point has been applied to fish muscle“ and
`other animal muscle.45 The protein recovery (dry basis)
`yield from krill using isoelectric solubilization/precipita-
`tion is approximately 90% or greater in a continuous
`mode. A more in-depth discussion of the isoelectrical
`solubilization recovery of krill is available elsewhere.3
`Table 446 shows the amino acid composition of krill
`
`protein concentrate compared with that of other commer-
`cially available protein concentrates such as casein, whey,
`and soy protein. The indispensable amino acid profiles of
`the protein concentrates were compared with the indispens-
`able amino acid requirements for adults and infants because
`protein concentrates are frequently used in infant formulas.
`As shown in Table 4, krill protein concentrate contains all
`indispensable amino acids in amounts that exceed the re-
`quirements for healthy adults. Krill protein concentrate also
`contains all of the indispensable amino acids in amounts
`that meet the requirements for infants (although leucine,
`tryptophan, and histidine levels were slightly below). Milk-
`
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`Table 4. Amino Acid Composition of Krill (Euphausia superba) Protein Concentrate, Whey Protein
`Concentrate, Sodium Caseinate, and Soy Protein Concentrate Compared with the Amino Acid Requirements
`for Infants and Adults*
`
`Sodium
`Caseinate
`
`
`
`lsoleucine
`Leucine
`
`Lysine
`Methionine +
`
`cysteine
`
`tyrosine
`
`56
`33
`34
`44
`
`96
`
`1
`
`Dispensible Amino Acids
`4
`Arginine
`Alanine
`
`Aspartic acid
`Glutamine
`
`Proline
`Serine
`
`17.3 _
`18.4
`7.8
`
`.
`
`91.8
`1 5 8 .4
`
`10.4
`56.4
`25
`
`,
`
`75:7
`218.4
`
`; values for whey and soy protein concentrate are based on USDA ;
`* Values for krill are based on Torres et al.
`values for sodium caseinate are based on Sindayikengera and'Xia46; requirements for infants and adults are based on
`FAO/WHO/UNU”.
`ND, Not determined.
`
`derived whey protein concentrate, sodium caseinate, and
`soy protein concentrates are more deficient in the indispens-
`able amino acids for infants than are krill protein concen-
`trates.
`
`The amount of indispensable amino acids in krill
`protein concentrate is higher than that in soy protein
`concentrate and similar to that of the milk protein casein.
`Sidhu et al.29 reported that rats fed krill protein concen-
`trate had similar weight gain and protein efficiency ratio
`as‘rats fed casein. Although higher than casein, krill
`protein concentrate is low in threonine, leucine, lysine,
`and the sulfur amino acids (methionine and cysteine)
`
`compared with the whey protein concentrate (Table 4).
`This has important health implications because sulfur
`amino acids are involved in DNA transcription and RNA
`translation and may play a role in reducing the risk of
`CVD, dementia, cirrhosis, and immunomodulation.“
`The health benefits and safety issues regarding the use of
`alternative protein sources need to be investigated in
`more detail.
`
`The Health Benefits and Safety of Krill Protein
`
`Adequate protein intakes are necessary for synthesis
`of structural components of the muscle and of enzymes,
`
`hormones, hemoglobin, and other body tissues. Sidhu et
`al.29 reported that
`rats fed krill protein concentrate
`showed no difference in organ weights and hemoglobin
`counts than rats fed casein, indicating that krill protein is
`capable of supporting protein synthesis. Too much rather
`than too little protein is typical of the Western diet.
`Consuming protein beyond recommended amounts is
`common among athletes interested in increasing their
`muscle mass. The general population has also recently
`developed an interest in increasing their protein intakes
`due to suggestions that high-protein diets support weight
`loss, and there is some evidence that short-term con-
`sumption of high-protein diets increases satiety and ther-
`mogenesis and reduces energy intake.48 However, de-
`spite growing interest in proteins, the long-term effects
`of high-protein diets on weight loss are unknown and
`there may be harmful effects associated with such diets.
`For example, diets high in protein have been suggested to
`increase the risk for cardiac, renal, bone, and liver
`disease.”
`
`High-protein diets have also been suggested to in-
`crease the risk of CVD by inducing negative effects on
`blood lipid profiles. However,
`the negative effects on
`blood lipids are more likely due to the high SFA intakes
`associated with most high-protein diets, Krill, unlike
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`low in SFAs.
`is
`other animal sources of proteins,
`Obatakezz reported no difference in serum cholesterol
`levels for rats fed boiled whole krill or krill meat com.-
`
`V
`pared with animals fed casein.
`Another area of concern is the use of alternate
`
`protein sources in infant formulas. Soy protein has been
`reported to accelerate puberty in female rats compared
`with.whey and casein.” Other concerns regarding alter-
`native protein sources are their ability to support growth
`and their long-terrn health effects.5° In addition, all food
`proteins have the potential
`to be allergenic to some
`people. Approximately‘ 1% to 2% of adults and up to 5%
`to 7% of children experience food allergies with symp-
`toms ranging from a mild rash to life-threatening ana-
`phylaxis.51 The Food and Agricultural Organization of
`the United Nations includes crustaceans on its list of the
`
`eight most significant food allergens.” According to
`Wild and Lehrer,53 shellfish is the number-one cause of
`food allergies in adult Americans. To our knowledge, no
`studies have examined whether krill protein or krill
`protein concentrate causes food allergies. Determining
`the protein allergens present in krill and the relative
`allergenic activity of krill compared with other major
`protein substitutes is important. For example, soy protein
`used to manage cow’s milk allergies in infants has been
`reported to have less allergenic reactivity compared with
`milk proteins; however, concerns have been raised re-
`garding the isoflavone content in soy infant formulas
`affecting neurobehavioral development, immune, endo-
`crine, and thyroid function.“ Krill protein concentrate,
`which has an indispensable amino acid profile superior to
`that of soy protein concentrate, may be a better protein
`substitute in infant formulas if its allergenic reactivity is
`found to be lower than that of other protein sources.
`Finally, the high protein levels achievable with pro-
`tein concentrates and isolates have been suggested to
`increase the risk of kidney damage, particularly in the
`immature kidneys of infants. Rats fed semi-purified diets
`containing soy protein or casein have been reported to
`have an increased incidence of nephrocalcinosis.55
`Neplirocalcinosis may be caused by a number of condi-
`tions, including excretion of excess calcium by the kid-
`neys. Increased calcium excretion (calciuria) by the kid-
`neys due to high-protein diets has been attributed to the
`sulfur amino acids increasing the acid load in the body,
`followed by the release of calcium from the tissues to
`restore acid-base balance.56 Calcium released from the
`bone to restore acid-base balance has led to suggestions
`
`that high-protein diets may contribute to bone loss._ In
`addition, rats fed semi-purified diets containing soy pro-
`tein have been reported to have reduced mineral absorp-
`tion.55 The calciuria and reduced mineral absorption
`associated with high-protein diets may contribute to
`
`negative mineral balance, leading to bone loss and in-
`_ creasing the future risk of osteoporosis. Furthermore,
`minerals may be lost during the processing of whole
`foods into protein concentrates. The next section assesses
`the mineral content of whole krill and krill following
`processing into edible products.
`
`KRILL MINERAL CONTENT
`
`The mineral content of shellfish is to a large extent
`located in the exoskeleton, which is removed to produce
`krill meat and krill protein concentrate. Figure 4A com-
`pares the level of selected minerals in whole krill, krill
`meat, and krill protein concentrate, along with the RDA
`of these minerals for adults. In whole krill, the content of
`
`major minerals involved in bone health (calcium, phos-
`phorus, and magnesium) met the RDA. Following re-
`moval of the exoskeleton to produce krill meat, calcium
`was reduced by 84.4%, phosphorus by 47.3%, and there
`were minute effects on magnesium. As airesult, krill
`meat was below the RDA for calcium and phosphorus
`(Figure 4A). Processing of whole krill into krill protein
`concentrate reduced calcium by 78.6%, phosphorus by
`14.4%, and magnesium by 83.5%. The phosphorus con-
`tent in krill protein concentrate met the RDA, but cal-
`cium and magnesium were both below the RDA (Fig-
`ure 4A).
`Another important dietary mineral is iron. Identify-
`ing good food sources of iron is important because iron
`deficiency is
`the most common nutritional disorder
`worldwide.” Anemia clue to iron deficiency has been
`associated with significantly lower scores in cognitive
`and educational achievement tests in school-age chil-
`dren57 and lower work productivity in adults.” Removal
`of the exoskeleton to obtain krill meat and processing to
`krill protein concentrate have minute effects on the level
`of iron in krill (Figure 4B). Still, the iron content of krill
`does. not meet the RDA for adult women (18 mg/d) or the
`lower RDA for adult men (8 mg/d). King et al.59 deter-
`mined the mineral content of shellfish commonly mar-
`keted in the northwestern United States, and found that
`shellfish in general is low in iron, with the exceptions of
`oysters, mussels, and clams, which have levels compa-
`rable to red meat.
`Most foods are low in fluoride, but krill
`
`is an
`
`exception. Fluoride is important for the mineralization of
`bone and teeth and in the prevention of dental caries.
`Furthermore, the use of high-dose fluoride is being in-
`vestigated for the prevention of osteoporosis.” The flu-
`oride content of krill is concentrated in the exoskeleton,
`where it may reach concentrations of 350 mg/100g dry
`weight.“ At~death,
`the fluoride in krill
`is capable of
`migrating from the exoskeleton into the soft
`tissues.
`
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`Magnesium
`
`
`Female RDA >II6I¢I0I¢I"'
`Male RDA C?X?X?¢I?1'?X?I?Z?X?ItX?1
`
`Phosphorus
`
`fitititititztitififititit$tXt'2X2313tXt§
`
`
`mm
`1000
`0
`500
`
`1500
`
`mg/100g
`
`5 Whole Krill
`Krill Meat
`I KPC
`EJ RDA
`
`B Whole Krill
`Krill Meat
`I KPC
`RDA
`
`Calcium '..232.3%:32$2$I$2v2o2o2«2o232$2$232$2$:32$t3231$2$.313§
`OA¢.¢;¢A¢.O.¢AO.OAOAO.O.¢.¢A§A¢.§.¢A .
`
`Iron
`
`Female RDA
`
`,T,v,.,..,.,.,v,.,.,v,.,.,.,..,.,v,v,. v,.,.,.,.,.,.,.,.,.,.,. .,v,v,.,.,.,.,.,v,._
`vv
`>’o’4»’o’o‘o’o‘o‘o’o’o’o’o‘o’¢‘¢“o‘¢‘o’¢o’o‘o‘¢’o’¢’o‘¢’o‘o’¢’o’o’¢“¢’o’o"o’¢"¢
`-’¢'¢’¢*¢‘e-‘A
`99
`Male RDA riotvtotdtototoioA¢.¢.o.¢,.¢A¢.o.o.¢
`
`O9
`
`mg/l00g
`
`Figure 4. Mineral content of whole krill and krill following processing into meat and protein concentrate along with the
`61)
`recommended dietary allowance of these minerals-for adults. (Fluoride value in krill meat is based on Virtue et al.
`
`Budzinski et al.62 reported fluoride levels as high as 9
`mg/100 g wet weight in krill meat. The fluoride derived
`from krill is also highly bioavailable. Tenuta-Filho and
`Alvarenga63 reported that weanling male rats fed krill
`exoskeleton had 80% absorption of fluoride. The high
`fluoride content of krill, together with the high bioavail-
`ability of this fluoride, has led to concerns about the
`potential for toxicity. Careful removal of the exoskeleton
`before consuming krill and immediate removal of the
`shell upon harvest to prevent migration of fluoride into
`the muscle can minimize potential toxicity since over
`99% of the fluoride content of krill is associated with the
`exoskeleton.“
`'
`Overall, the evaluation of the mineral content of krill
`indicated that it is a poor source of iron. Whole krill
`meets the RDA for minerals important for bone health;
`however, depending on the technology used to process
`krill into edible products, mineral losses may occur that
`
`result in mineral levels below the RDA. On the other
`
`hand, processing typically removes potentially toxic lev-
`els of fluoride. In the processing of shellfish, by—products
`represent approximately 50% to 70% of the weight of the
`raw material, much of which is
`the exoskeleton.“
`Whether the by-products generated by processing of krill
`into food may be developed into value—added products is
`another important consideration. In the next section,
`potential value-added products generated from krill are
`assessed.
`
`VALUE-ADDED PRODUCTS
`
`Chitin
`
`Chitin is a polysaccharide comprised of units of
`N-acetyl-2 amino~2-deoxy-D—glucopyraose (C8H15O6N)
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`bound by [3(l, 4) glycosidic links found in the exoskel—
`eton of crustaceans, insects, and fungi.“ Chitin and its
`derivative chitosan have a wide range of applications in
`the food, pharmaceutical, textile, agriculture, and cos-
`metic industries.“ Crustacean by-products are the major
`source of commercially available chitin.“ Figure 5 com-
`pares the amount of chitin in the exoskeleton of various
`crustaceans. Krill has a higher percentage of chitin than
`other more highly exploited shellfish such as crab and
`shrimp. The chitin composition of whole krill has been
`reported to be between 2.4% and 2.7% of their dry
`weight, making it an abundant source of chitin.69
`Chitin is the raw material used for the production of
`chitosan, which has been promoted as a supplement for
`reducing body weight, hypercholesterolemia, and hyper-
`tension.7° Chitosan differs from other weight-loss prod-
`ucts because it does not claim to increase energy expen-
`ditures or induce satiety. Instead, orally administered
`chitosan binds to dietary fat and prevents it from being
`absorbed.“ Increased fat excretion during chitosan ad-
`ministration has been demonstrated in animal studies.”
`However, the dosages of chitosan used in animal studies
`are 15 to 22 times higher than the recommended dose for
`humans. In a review by Mhurchu et al.,73 the effective-
`ness of chitosan as a weight loss treatment in humans
`was examined. Evidence indicated that chitosan was
`
`more effective in short-term studies than placebo for
`promoting weight loss in overweight and obese subjects.
`However, the authors cautioned that many of the studies
`were of poor quality and recommended that more re-
`search be performed before any definitive conclusion
`regarding the role of chitosan as a weight loss agent be
`made.
`
`Chitosan has also been suggested to play a role in
`CVD by binding negatively charged substances such as
`fatty acids and bile acid. This in turn reduces fat absorp-
`tion and increases fecal sterol excretion, which lowers
`serum cholesterol. Chitosan has been demonstrated to
`
`produce significant hypocholesterolemic activity in dif-
`ferent experimental animals,“ but only a few studies
`have been conducted using human subjects. In a review
`by Ylitalo et al.,74 dietary chitosan was found to have
`only modest effects on total cholesterol and LDL. Other
`health benefits attributed to chitosan are reduced systolic
`and diastolic blood pressure and anti-ulcer, anti-arthritic,
`and anti-uricemic properties.“ Potential adverse effects
`of chitosan include gastrointestinal symptoms such as
`constipation, fiatulence, and the risk of fat-soluble vita-
`min deficiency due to reduced fat absorption. Along with
`krill enzymes, chitin is one of the potentially lucrative
`by-products generated by the production of krill
`into
`edible products.
`
`Krill Enzymes
`
`The digestive glands of krill produce hydrolytic
`enzymes including proteases, carbohydrases, nucleases,
`and phospholipases.75 These enzymes are released upon
`the demise of krill, resulting in rapid autolysis. Autolysis
`leads to spoilage and is a major hindrance to the harvest
`of krill. However, there is growing interest in the medical
`applications of krill enzymes, which have been studied
`for use in treating ulcers and promoting wound healing
`due to their effective debridement of necrotic tissue.76‘77
`Melrose et al.78 indicated that krill enzymes may be used
`as a chemonucleolytic agent
`to reduce the height of
`
` TT
`
`
`
`Blue crab
`
`Prawn
`
`Crayfish
`
`15
`
`20
`
`25
`
`30
`
`35
`
`Figure 5. Chitin content in the exoskeletons of various shellfish. (Adapted from Synowiecki and Al-Khateeb.
`
`68)
`
`% dry basis of shell waste
`
`74
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`
`vertebral disks, which diminishes disk pressure on in-
`flamed nerve roots, thereby alleviating sciatic pain. Stud-
`ies have also reported that krill enzymes release mi-
`crobes from plaque in vitro and remove plaque on
`dentures, indicating potential benefits in oral health.”
`Thus, krill products for human consumption and medical
`applications for krill by-products may be developed in
`parallel.
`
`CONCLUSIONS
`
`Based on its nutrient composition, krill appears to be
`a suitable food for human consumption. It has the ben-
`efits of being high in on-3 PUFAS and a rich source of
`high-quality proteins. However,
`further research is
`required to determine whether components such w-3
`PUFAs and protein derived from krill exert the same
`health benefits as when provided by different sources.
`The development of krill into edible foods must also take
`into consideration that processing may affect its nutritive
`value; for example, the mineral losses associated with
`removal of the exoskeleton. Other areas requiring further
`research include the development of value-added prod-
`ucts from the by-products generated by the processing of
`krill into food. Finally, it is critical to be cognizant that
`despite the seemingly limitless biomass provided by
`krill, a careful approach to krill stock management needs
`to be in place to ensure its long-term sustainability as a
`food source for humans.
`
`REFERENCES
`
`1. Vannuccini S. Overview of fish production, utiliza-
`tion, consumption and trade. Rome: Food and Ag-
`riculture Organization Fisheries Information, Data
`and Statistics Unit; 2004.
`2. Krauss RM, Eckel RH, Howard B, et al. AHA Dietary
`Guidelines: revision 2000: a statement for health-
`care professionals from the Nutrition Committee of
`the American Heart Association. Circulation. 2000;
`102:2284-2299.
`3. Torres JA, Chen YC, Rodrigo—Garcia J, Jaczynski J.
`Recovery of by-products from seafood processing
`streams. In: Shahidi F, ed. Maximising the Value of
`Marine By—products. Cambridge (UK): Woodhead
`Publishing; 2007:65—95.
`4. Kolakowski E, Lachowicz K. Application of partial
`autoproteolysis to extraction of protein from Antarc-
`tic krill (Euphausia superba). Part 3. Changes in and
`yield of nitrogen substances during autoproteolysis
`of fresh and frozen krill. Die Nahrung. 1982;26:933-
`939.
`5. Everson I. Introducing krill. In: Everson I, ed. Krill:
`Biology, Ecology and Fisheries. Malden, MA: Black-
`well Sciences Ltd; 2000:1—7.
`6. Nicol S, Endo Y. Krill Fisheries of the World. FAO
`'
`Fisheries Technical Paper 367; 1997.
`7. Hamner WM, Hamner PP, Strand SW, Gilmer RW.
`
`Behavior of Antarctic krill, Euphausia superba: Che-
`moreception, feeding, schooling, and molting. Sci-
`ence. 1983;220:433-435.
`Nicol S, Forster I, Spence J. Products derived from
`krill. In: Everson I, ed. Krill: Biology, Ecology and
`Fisheries. Malden, MA: Blackwell Sciences Ltd;
`2000:262—283.
`Suzuki T, Shibata N. The utilization of Antarctic krill
`for human food. Food Reviews International. 1990;
`6:119-147.
`USDA (United States Department of Agriculture)
`Agricultural Research Service.—USDA National Nu-
`trient Database for Standard Reference, Release 17;
`2004. Available at: http://www.ars.usda.gov/main/
`site_main.htm?modecode=12354500. Accessed
`January 8, 2007.
`Grantham GJ. The Southern Ocean: The utilization
`of krill. Southern Ocean Fisheries Survey Pro-
`gramme. FAO Rome GLO/SO/7/3, 1977; 1-61.
`Hu FB, Manson JE, Willett WC. Types of dietary fat
`and risk of coronary heart disease: a critical review.
`J Am Coll Nutr. 2001;20:5-19.
`Saether O, Ellingsen TE, Mohr V. Lipids of North
`Atlantic krill. J Lipid Res. 1986;27:274-285.
`_
`Kolakowska A. The influence of sex and maturity
`stage of krill (Euphausia superba Dana) upon the
`content and composition of its lipids. Polish Pol
`Res. 1991;12:73-78.
`Kolakowska A, Kolakowski E, Szcygielski M. Winter
`season krill (Euphausia superba Dana) as a source
`of n-3 polyunsaturated fatty acids. Die Nahrung.
`1994;38:128-134.
`Weihrauch JL, Posatl LP, Anderson BA, Exler J.
`Lipid conversion factors for calculating fatty acid,
`contents of foods. J Am Oil Chem Soc. 1977;54:36-
`40.
`Aral K, Watanabe T, Kinumaki T. Bull Tokai Reg Fish
`Res Lab No. 85; 1976.
`Bottino NR. Lipid composition of two species of
`Antarctic krill: Euphausia superba and E. crystal-
`lorophias. Comp Biochem Physiol B. 1975;50:479-
`484.
`
`Watanabe T, Sugii R, Yuguchi H, Kinumaki, T. Bull
`Tokai Reg Fish Res Lab No 85;1979.
`Feeley RM, Criner PE, Watt BK. Cholesterol content
`of foods. J Am Diet Assoc. 1972;61:134-149.
`Vahouny GV, Connor WE, Roy T, Lin DS, Gallo L.
`Lymphatic absorption of shellfish sterols and their
`effects on cholesterol absorption. Am J Clin Nutr.
`1981;34:507-518.
`Obatake Y, lshiguro N, Hirahara F, Innan S, Nihide
`E. Eiyougaku Zaashi. 1980;38:311-314.
`Shagaeva MM, Slavina LS, Balabokin MI, Sobenin
`IA, Orekhova AN. Effect of squid liver fat and krill
`meat on blood serum atherogenicty in patients with
`type I diabetes mellitus. Probl Endokrinol (Mosk).
`1993;135:1001-1010.
`Bunea R, El Farrah K, Deutsch L. Evaluation of the
`effects of neptune krill oil on the clinical course of
`hyperlipidemia. Altern Med Rev. 2004;9:420-428.
`Harris WS. Omega-3 fatty acids and serum |ipopro-
`teins: human studies. Am J Clin Nutr. 1997;
`65(suppl):1645S—1654S.
`
`10.
`
`11.
`
`12.
`
`13.
`
`14.
`
`15.
`
`16.
`
`17.
`
`18.
`
`19.
`
`20.
`
`21.
`
`22.
`
`28.
`
`I
`
`24.
`
`25.
`
`Nutrition Reviews®, Vol. 65, No. 2
`
`00000177
`
`75
`
`00000177
`
`

`
`26.
`
`27.
`
`28.
`
`29.
`
`30.
`
`31.
`
`32.
`
`33.
`
`34.
`
`3'5 .
`
`36.
`
`37.
`
`38.
`
`39.
`
`40.
`41 .
`
`42.
`
`76
`
`Smith KM, Sahyoun NR. Fish consumption: recom-
`mendations versus advisories, can they_be recon-
`ciled? Nutr Rev. 2005;63:39-46.
`Harris WS. Fish oils and plasma lipid and lipoprotein
`metabolism in humans: a critical review. J Lipid Res.
`1989;30:785-807.
`Din JN, Newby DE, Flapan AD. Omega 3 fatty acids
`and cardiovascular disease-fishing for a natural
`treatment. BMJ. 2004;328:30-35.
`Sidhu GS, Montgomery WA, Holloway GL, Johnson
`AR, Walker DM. Biochemical composition and nu-
`tritive value of krill (Euphausia superba Dana). J Sci
`Food Agric. 1970;21:293-296.
`Sampalis F, Bunea R, Pelland MF, Kowalski O,
`Duguet N, Dupuis S. Evaluation of the effects of
`Neptune krill oil on the management of premen-
`strual syndrome and dysmenorrhea. Altern Med
`Rev. 2003;8:171—179.
`Kinumaki T. Comprehensive studies on the effective
`utilization of krill resources in Antarctic Ocean. Sci-
`ence and Technology Agency, Japan; 1980:57—65.
`DRI (Dietary Reference Intakes) for energy, carbo-
`hydrate, fiber, fat, fatty acids, cholesterol, protein,
`and amino acids. Standing Committee on the Sci-
`entific Evaluation of Dietary Reference intakes,
`Food and Nutrition Board. Institute of Medicine of
`the National Academies. National Academy of Sci-
`ences; 2005.
`Hussein G, Sankawa U, Goto H, Matsumoto K,
`Watanabe H. Astaxanthin: a carotenoid with poten-
`tial in human health and nutrition. J Nat Prod. 2006;
`69:448-449.
`Miki, W., Hosoda, K., Kondo, K., and ltakura, H.
`Astaxanthin—containing drink. Patent application
`number 10155459. Japanese Patent Office. Publi-
`cation date 16 June 1998.
`Dunlap WC, Fujisawa A, Yamamoto _Y, Moylan TJ,
`Sidell BD. Notothenioid fish, krill and phytoplankton
`from Antarctica contain a vitamin E constituent (al-
`pha-tocomonoenol)
`functionally associated with
`cold—water adaptation. Comp Biochem Physiol B
`Biochem Mol Biol. 2002;133:299—205.
`Venkatraman JT, Chandrasekar B, Kim JD, Fer-
`nandes G. Effects of n-3 and n—6 fatty acids on the
`activities and expression of hepatic antioxidant en-
`zymes in autoimmune-prone NZBxNZW F1 mice.
`Lipids. 1994;29:561-568.
`Strain'JJ, Dowey L, Ward M, Pentieva K, McNulty
`HB. Vitamins, homocysteine metabolism and CVD.
`Proc Nutr Soc. 2004;63:597-603.
`Young VR, Pellett PL. Protein evaluation, amino acid
`scoring and the Food and Drug Administration’s
`proposed food labeling regulations. J Nutr. 1991;
`121:145-150.
`FAO/\NHO/UNU. Energy and protein requirements.
`Report of a join