• Korean Journal of Ichthyology
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• v.5 no.2
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• pp.177-183
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• 1993

Results comparing the scale and otolith ages for walleye pollock from the Donut Hole of the Bering Sea showed a significant discrepancy for fish older than 8 years old. For walleye pollock from the Shelikof Strait of the Gulf of Alaska, comparison between ages determined from the scale and otolith readings indicated that there were no differences for younger age groups, but for the ages 6 and older, discrepancies squeezed in somewhat amid the same age groups.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.249-257
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• 2009

This study is conducted to partially purify an antioxidative peptide in a two-step gelatin hydrolysate from Alaska pollock surimi refiner discharge, which was obtained by sequential treatment with Pronase E and Flavourzyme. The two-step gelatin hydrolysate was fractionated using chromatographic methods. Based on the same protein concentration of each fraction, the antioxidative activities (85.1-95.4%) of positive fractions fractionated by ion-exchange chromatography were higher than those (27.2-87.8%) from gel filtration. Then, further purification of the positive fractions was performed. Among them, the partially purified A1C1L2G1 and A1C1L2G2 fractions showed 96.2% and 85.1% inhibition, respectively, of linoleic acid peroxidation. The A1C1L2G1 fraction was composed of 15 kinds of amino acids and the predominant amino acids were proline, glycine and alanine. The results obtained in this study suggested that the fraction partially purified through chromatographic methods from the two-step gelatin hydrolysate of Alaska pollock surimi refiner discharge could be useful as a supplementary source for improving health functionality.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.62-68
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• 2017

The Alaska pollock (Gadus chalcogrammus) belongs to the family Gadidae; it is a cold water fish, and has been developed as a novel aquaculture species in Korea. In this study, we describe ongoing surveillance for aquatic animal pathogens based on growth stages. We investigated bacterial flora in rearing water, and monitored pathogens; we also analyzed histopathological traits of abnormal fish. In rearing water, the total bacterial counts were $2.1{\times}10^3cfu/mL$ and Vibrio spp. (52%) were predominant in the larvae stage. In the juvenile and adult stages, the total bacterial counts were $3.4{\times}10^3$ and $3.2{\times}10^2cfu/mL$, respectively (with Pseudomonas sp. as the predominant species; 90% and 52%). This result revealed that the bacterial flora in rearing water changed depending on the feeding types. No virulent-bacteria or problematic viruses (VHSV, viral hemorrhagic septicemia virus; NNV, nervous necrosis virus; MBV, marine birnavirus) were detected from outwardly healthy fish using either culture or PCR assay. Some juveniles (less than 5%) had gas bubbles on the gill lamellae, degeneration of the corneal epithelium, and choroid gland degeneration, suggesting that these symptoms were caused by external injury and secondary infection by opportunistic bacteria. Disease management is important to cope with disease emergence in the novel aquaculture species Alaska pollock.

• 한국해양학회지
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• v.28 no.1
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• pp.35-46
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• 1993

To delineate water properties and current patterns in the spawning area of walleye pollock, hydrographic cast and current meter data collected in Strait, Gulf of alaska, were analysed, three water masses are identified in Shelikof Strait. A small amount of cold and dilute water ($<{\;}3^{\circ}C{\;}and{\;}<{\;}31.5\textperthousand$) originates from the lower Cook Inlet and flows southwestward close to the Alaska Peninsula coast. One branch of alaska coastal Current which enters the strait from the northeast comprises the main body of the upper and middle layers of the strait, and flows toward the southwest. Estimation of geostrophic baroclinic currents reveals that comparatively fast flow exists in the surface over the deepest portion of the strait, and most water exits through the southwestern entrance between Semidi and chirikof Is. On the other hand, a relatively slow-moving warm and saline ($>{\;}5^{circ}C{\;}and{\;}>{\;}32\textperthousand$) of the southwestern entrance flows northeasterly, and occupies the bottom layer in Shelikof Strait.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.584-590
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• 2009

The effects of different washing time and pH adjustment of surimi-like materials from pork leg on quality characteristics were investigated. Surimi was made from pork leg by washing two or four times with water, as well as by pH adjustments of 3.0 or 11.0. The control surimi was made by two times washing from Alaska pollock. The content of crude protein was higher in the surimi manufactured from pork leg with pH adjustments. The highest gel strength was found in the control, and the control had greater lightness and whiteness value. The control had higher texture attributes than the other samples, whereas the surimi from pork leg made by a pH 11.0 adjustment had higher texture attributes than the pH 3.0 adjustment. The sensory color was higher in the control compared to other surimi samples, whereas aroma was lower in the control. However, there were no significant differences in overall acceptability among the surimi samples.

• The Journal of Fisheries Business Administration
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• v.17 no.1
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• pp.107-115
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• 1986

The United States is the world's leading importer of frozen processed groundfish products, with over two thirds of total world imports. Over 90% of the U.S. groundfish demand is met by inports, while about 2 million mt of groundfish are taken from U, S. waters by joint-venture and foreign fleets. The objective of this paper is to provide descriptive information concerning the U.S. groundfish market and the potential for groundfish resources off Alaska to become a major source of supply to this market. The size of the U.S. market, U.S. imports, trade policies, and catch from U.S, waters are discussed, and a comparison is made between the potential domestic catch of groundfish off Alaska and current U.S. groundfish consumption. The total optimum yield of 2.3 million mt for flounders, cod, and pollock is about four times the round weight equivalent of U.S. imports of these species in 1984.

• Journal of Life Science
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• v.25 no.11
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• pp.1280-1289
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• 2015

Fish-meat gel is being produced mostly relying on surimi and raw materials imported from Southeast Asia and North America and present in small amount in local markets. In this study, common farmed local fishes were examined as stable and reliable sources of surimi for fish-meat gel production. For testing, five main farmed-fish of Korea, namely; Bastard halibut (Paralichthys olivaceus), Red sea bream (Pagrus major), Korean rockfish (Sebastes schlegeli), Common mulle (Mugil cephalus), and Finespotted flounder (Pleuronichthys cornutus) were used following a traditional washing process. The quality of the surimi was determined by the values of water content, whiteness index, gel strength and impurity. Accordingly, fish-meat gel and surimi quality experiments were carried out by measuring compressive and texture properties, expressible moisture content, Hunter color scale values and SDS-page protein patterns. Also gel characteristics were compared with that of FA and RA grade surimi (Alaska Pollock). Fish-meat gels were prepared by salt mincing the farmed-fish surimi with NaCl (2% w/w) and moisture adjustment to 84% by ice water adding. Prepared fish-meat paste was filled into 20-25 cm long polyvinylidene chloride casings and heated at 90℃ for 20 min. The whiteness values of fish-meat gels produced from surimi were increased by using farmed-fish and became comparable to that of FA Alaska Pollock gel. Among all tested farmed-fish, P. olivaceus and P. major exhibited better properties than RA Alaska Pollock and similar properties to FA Alaska Pollock. Therefore, current data suggests that fish farming can be an efficient and sustainable fish-meat source for fish-meat gel production in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.207-214
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• 2012

This study was conducted to optimize the processing conditions, including the ingredient ratio and extraction time, for a water-soluble fraction of Alaska pollock head and non-forming sea tangle by response surface methodology. Our results indicated that the optimal independent variables for obtaining extracts with a high yield and desirable sensory characteristics were 1.32 for $X_1$ (extraction time), 1.36 for $X_2$ (sea tangle concentration) and 0.93 for $X_3$ (water volume) in coded values, and 5.48 h for $X_1$, 18.18% for $X_2$ and 6.86 times for $X_3$ in uncoded values. The predicted values of $Y_1$ (yield), $Y_2$ (TCA soluble-N) and $Y_3$ (overall acceptance) for extracts produced under these optimized conditions were 22.10%, 1.83 g/100 mL and 5.9, respectively, their experimental values were 21.4%, 1.7 g/100 mL and 5.7, respectively. No significant differences between the actual and predicted values were found.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.179-187
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• 2010

This study examined ways to improve the functional properties of commercial soy sauce using gelatin hydrolysates from the refiner discharge of Alaska pollock, Theragra chalcogramma. The total nitrogen content and pH of gelatin sauce prepared by dissolving the second-step gelatin hydrolysates (15 g), salt (20 g), sugar (5 g), glucose (2.5 g), inosine monophosphate (IMP) (0.5 g), black pepper (0.1 g), caramel powder (0.1 g), ginger powder (0.05 g), garlic powder (0.05 g), vinegar (3 mL), and fructose (3 mL) in water(100 mL) were 1.71% and 5.35, respectively. The results of a sensory evaluation indicated that when preparing blended soy sauce, the optimal blending ratio of gelatin sauce to commercial soy sauce was 20:80 (v/v). Because the total nitrogen content and pH of the blended soy sauce were 1.52% and 5.31, respectively, the blended soy sauce could be sold as a soy sauce. The oxidative property of the blended soy sauce was similar to that of 20 mM ascorbic acid, and its angiotensin-converting enzyme (ACE) -inhibiting activity was 1.5 mg/mL. The results suggest that the antioxidative and ACE-inhibiting activities of commercial soy sauce can be improved by blending gelatin sauce (20) with commercial soy sauce (80). The total amino acid content of the blended soy sauce was 9,107.3 mg/mL, which was higher than that (8,992.4 mg/100 mL) of commercial soy sauce. However, the taste value of the blended soy sauce was 415.8, which was lower than that (431.2) of commercial soy sauce.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.161-162
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• 2006