• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.159-165
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• 2014

In this study, Krill Eupausia superba oil was extracted using different solvents and supercritical carbon dioxide (SC-$CO_2$). During SC-$CO_2$ extraction, the pressure was set at 40 MPa and temperatures ranged from $40^{\circ}C$ to $55^{\circ}C$. We examined the differences in volatile compounds and safety profiles among extraction methods. Volatile compounds were determined using the thermal desorption system integrated with gas chromatography-mass spectrometry (GC-MS). Heavy metal content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). According to our results 10 volatile compounds were identified in krill sample. After SC-$CO_2$ extraction of oil, the concentrations of volatile compounds decreased, but increased after solvent extraction. In krill, heavy metal concentrations remained within the permissible limit. Moreover, Zn and Fe which have health benefits were detected at high concentrations. During a 90 days storage period at different temperatures, microbial activity was found to be lowest in SC-$CO_2$ extracted residues. Thus, the quality of krill oil and the residues obtained using SC-$CO_2$ extraction was higher and the oil was safer than those obtained using conventional solvent extraction. These results can be applied to the food industry to maintain high quality krill products.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.47-52
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• 2014

Antarctic krill (Euphausia superba) is typical of a enormous biomass of marine zooplankton that could provide good nutrition in human body. This study was conducted to identify the nutrition of krill, a live in Antarctic Ocean. The analysis result of fatty acids of krill meal was as follow. The compositions of fatty acid were saturated fatty (SFA) acid 41.41%, monounsaturated fatty acid (MUFA) 21.69%, polyunsaturated fatty acid (PUFA) 36.89%, and p/s ratio was 0.89. The major fatty acids in all parts were eicosapentaenoic acid (EPA, 21.54%), palmitic acid (27.51%), oleic acid (13.35%) and docosahexaenoic acid (DHA, 12.42%). Especially, EPA and DHA were occupied 33.96% of polyunsaturated fatty acid. The mineral contents of krill meal were calcium 24477.21 mg $kg^{-1}$, sodium 14728.69 mg $kg^{-1}$, magnesium 6973.49 mg $kg^{-1}$, potassium 3981.67 mg $kg^{-1}$, iron 395.33 mg $kg^{-1}$ and manganese 5.74 mg $kg^{-1}$. The contents of major vitamin were retinol 86717.37 ${\mu}g$ RE, ${\beta}$-carotene 44.87 ${\mu}g$ RE, tocopherol 2.60 mg, pantothenic acid 1.61 mg, indicating that krill meal contains large amount of retinol and ${\beta}$-carotene.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.409-419
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• 2014

The proximate composition and various specific components of Antarctic krill Euphausia superba, in the catch season between March and August were investigated. Frozen krill were freeze-dried and milled. The proximate composition comprised water, proteins, fats, ash, fatty acids, and amino acids, while the specific components were vitamins, minerals, nucleotides, betaine, and astaxanthin. The moisture content of the krill ranged from 77 to 80%, with the highest value in June, and the ash content was between 12 and 13%. The protein content was lowest in May, and the fat content was 18-19%, with the highest value in March. The amino acid content varied according to the season: taurine and glycine were highest in August; ${\beta}$-alanine was higher in April and May; and arginine, ornithine, and lysine were highest in March. The unsaturated fat content was ~50% and omega-3 fatty acids were highest in June. Oil-soluble vitamins A and E were highest in March, and the water-soluble vitamin content was less than that of oil-soluble vitamins. The mineral content was highest in June, and the most abundant mineral was sodium at 235.60 mg/100 g krill. The content of other minerals was lowest (2.94 mg/100 g) in April, except for lead. The nucleotide content was highest in July, while the betaine content was highest in April and lowest in June. The astaxanthin content was highest in May and ranged from 6 to 10 ppm in other months.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.957-966
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• 2003

Effects of Salmonella typhimurium lipopolysacharide(LPS) and dietary krill meal on the Growth and feed utilization were investigated in broiler chicks. Eight cages of five newly hatched chicks each were assigned and fed to one of the experimental diets containing 0.0,(basal) 0.5 or 1.0% krill meal during 3 weeks of experimental period. And half(four) of the eight cages were i.p. injected with saline or LPS(Immune response activation) every alternate day three times beginning 8 day-old during 2 week of age. Dietary krill meal did not affect growth, feed efficiency, nitrogen balance(NB), uric acid excretion, and ME utilization when the saline was injected. However, the immune response activation lowered daily gain and feed intake and NB and increased uric acid excretion, and the relative liver and spleen weight. Also, birds fed diet containing krill meal 1.0% reduced the feed efficiency and increased spleen weight, and ME and NB or ME required for gain compared with those fed basal and krill meal 0.5% diets in LPS-injected chicks. During recovery period from the immunological stress in 3rd week of age, the krill meal diet reduced the weight of liver and spleen, The results showcd that dietary krill meal did not affect the growth of broiler chicks, but the higher uric acid excretion or dietary ME value indicated the increased protein decomposition or absorption of dietary energy sources in immune response activated birds.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.309-313
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• 2000

For the use of Antartic krill(Euphausia superba Dana) as food resource, general composition, extracting condition of chitin and quality characteristics of chitosan were investigated. General composition of frozen krill(Euphausia superba Dana) was consisted of moisture 79.0%, protein 13.1%, lipid 4.0%, VBN 7.7mg%, ash 2.7%, others 1.2% and that of dried krill powder was moisture 5.6%, protein 56.1%, lipid 18.8%, ash 11.4%, others 8.1%. The condition of chitin extraction from krill powder was treated with 1N NaOH at $40^{\circ}C$ for removing protein, 1N HCl for excepting mineral substances and methanol for decoloring. The yield of chitin by new procedure developed was 3.7%. The composition of extracted chitin contents was moisture 7.1%, ash 0.4%, protein 3.5%, lipid 3.1%. The results of degree of deacetylation in chitosan at 50% NaOH, $121^{\circ}C$, for 2 hrs was showed 82%. At the same alkali concentration and reaction concentration, a longer reaction time gave a decreased degree of deacetylation. The apparant viscosity was 0.09241 Pa in 1% chitosan from krill and 0.13826 Pa in standard chitosan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.81-87
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• 1980

As a part of the experiments on-the utilization of krill, Euphausia superba, general composition, pH, volatile basic nitrogen, amino-N, and free individual amino acid were analyzed for invertigating the processing condition and quality factors in the salted and fermented krill. The results ascertained were shown that the propel concentration of salt was $ 22-27\%$ and addition of $3.9-5.9\%$ of ethyl alchool contributed to improve flavor and appearance of the salted and fermented krill. The amino-N of the salted and fermented krill showed a rapid increase as much as 3.2 times that of fresh krill. Free amino acid composition, aspartic acid, leucine, tyrosine, isoleucine and glutamic acid which were poor in fresh frozen krill showed a fast increasing tendency, whereas glycine, proline, lysine, arginine and alanine which were abundant in fresh frozen krill showed a slow increasing tendency during the process of salted fermenting.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.173-182
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• 2004

The effect of dietary Antartic krill(Euphausia Superba) meal on the performance of broiler chicks during the acute phase responses was studied. One d-old male broiler chicks(Avian) were fed on the experimental basal (0.0 % krill meal), and 0.5 and 1.0 % krill meal diets, and then the acute phase response were activated by injecting Salmonella typhymurium lipopolisaccharide(LPS) three times i. p. at 8, 10 and 12 day of age. The 1.0% krill meal diet group had reduced daily gain and feed efficiency during the acute phase response of the 2nd week of age, while during recovery from the acute phase response of the 3rd week of age the lowered performance disappeared. The acute phase response increased the relative weight of liver and spleen, and dietary krill meal enhanced the activities of MnSOD and Cu/ZnSOD in liver and erythrocyte cytosols during the acute phase response, although neither the acute phase response or dietary krill meal affected significantly PHA-p hypersensitivity. The results indicated that dietary krill meal affected the performance and SOD activity of broilers chicks during the acute phase response.

• Analytical Science and Technology
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• v.33 no.6
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• pp.262-273
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• 2020

A fluorine content analysis method for krill oils, which is a representative oil formulation in foods, was developed in compliance with the Korea Food and Drug Ministry's "Guidelines for Validation of Testing Methods Related to Food". Using this method for krill oils, the presence of impurities was evaluated via combustion-ion chromatography (C-IC). A review of published technical data on fluorine in krill oils showed that while the traditional wet potentiometric method was typically used, it was not reliable. Moreover, there was no food testing/analysis laboratory in Korea to perform a fluorine test analysis on such an oil matrix. Therefore, we identified halogen (fluorine) tests, developed to national and international standards, and developed a test method suitable for krill oils by selecting a C-IC method that is sufficiently applicable to the oil matrix. Based on the characteristics of the oil matrix, the optimal test method was established through various experiments by reviewing the concerns related to loss and interference in the preparation and introduction of samples. The fluorine content test was carried out on 11 krill oil products that were purchased online. Most products (with the exception of only one) were found to contain less than the reporting limit obtained by the test method. Furthermore, after additional testing, a high fluorine content of approximately 2,000 ~ 3,000 mg/kg was detected on the krill surface, although the concentration varied depending on the area of the krill. A comparison with samples from two ISO/IEC 17025 testing laboratories confirmed that there was no significant difference in the statistical analysis results obtained by ANOVA among the three laboratories. A testing guide for fluorine content analysis was completed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.326-333
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• 1984

The oxidation rate of krill lipids is very slow and no peroxides are accumulated even after long storage. By means of various chromatographic techniques and mass spectrophotometry, the primary antioxidant has been identified as ${\alpha}$-tocopherol. The phospholipid fractions did not show any antioxidative activity but peroxide-decomposing properties of total lipids depended upon the phospholipid contents. The peroxide-decomposing activities of phospholipids were due to the presence of polar materials generated during the storage. The most peroxide-decomposing fractions of oxidized krill lecithin by DEAE-cellulose column chromatography was low-molecule fraction (mean molecular weight: 182) and high-molecule fraction (mean molecular weight: 1942) was the next. The separation of peroxide-decomposing properties from low-molecule fraction was achieved by partitioning between chloroform and methanol/water. The methanol/water fraction showed strong peroxide-decomposing activities and main component of this fraction was assumed hydroxyamine compounds derived from choline.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.168-171
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• 1990

This study was purposed to elucidate the migration phenomenon of fluoride from the chitinous sections into the muscle flesh of the frozen krill during thawing. The fluoride content ratio between chitinous sections and muscle flesh in the frozen krill was 94.8 : 5.2. Among the several thawing methods used, migration velocity of fluoride was the highest in the krill thawed with microwave and the lowest in the krill thawed at low temperature $(4^{\circ}C)$. The migrated amount of fluoride after thawing was various depended upon the thawing methods, and the increased amount during thawing was 2-5 times higher than Initial amount before thawing.