• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.89-95
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• 2010

This study was conducted to investigate the efficacy of using a coating of gelatin extracted from refiner discharge to extend the shelf life of salmon during cold storage ($5^{\circ}C$). Relative percentage of moisture loss in gelatin-coated salmon during cold storage was less than that of uncoated salmon. The treatment of salmon with gelatin reduced volatile basic nitrogen (VBN) formation throughout the entire storage period. Measurements of the peroxide value (POV), fatty acid composition, and (20:5n-3+22:6n-3)/16:0 ratio during cold storage indicated that the coating of salmon with gelatin from refiner discharge effectively suppressed lipid oxidation over the entire storage period. The extent of sensory color change during cold storage was less in the gelatin-coated than in the uncoated salmon. From the results of chemical measurements, such as relative moisture content, VBN, POV, fatty acid composition, (20:5n-3+22:6n-3)/16:0 ratio, and sensory color change, the conclusion was made that the coating treatment of salmon with refiner discharge gelatin effectively suppressed moisture loss, lipid oxidation, and color deterioration over the entire storage period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.583-587
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• 2020

Imitation fish roe (IFR) based on calcium alginate hydrogels (CAG) can be heat treated for sterilization and salted to prolong the shelf life. However, these processes change the physical properties of IFR, and it is necessary to minimize these changes. In this study, we investigated the effects of xanthan gum (XG) treatment on the quality and stability of IFR. Both non-XG and XG-treated IFRs were treated with boiling water (95℃), sodium chloride (0.5-2.0%, w/v), and autoclaving. The non-XG treated IFR shrunk slightly after the boiling water and autoclaving processes. By comparison, shrinkage of the XG-treated IFR after autoclaving was significantly reduced. The sphericity of the non-XG treated IFR was reduced by the boiling water, sodium chloride, and autoclaving treatment. However, the sphericity of the XG-treated IFR was maintained by 90% or more, preserving the IFR shape at a level visually recognized as spherical. In addition, unlike the non-XG treated IFR, the XG-treated IFR showed high rupture strength even after the salt and heat treatments. Our findings provide useful information for the industrialization of IFR based on CAG with heat and salt treatments.

• ALGAE
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• v.35 no.2
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• pp.107-121
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• 2020

Mariculture is regarded as the only option to supply the increasing demands for seaweeds as human food, feeds, fodder, and phycolloids in a sustainable manner. Technologies for culturing a range of seaweed species have been developed successively in Korea since the 1970s. In 2017, Korean marine farms produced 1,761,526 t of seaweed. The key focus of the industry is on the production of Pyropia (523,648 t), Undaria (622,613 t), and Saccharina (542,285 t). Pyropia is economically the most important species in Korea, accounting for up to 68% of total production value. As the top exporter of Pyropia in the world, Korea exported up to US $525 million of Pyropia products to 110 countries in 2018. Other economically important genera include Sargassum, Ulva, Capsosiphon, Codium, and Gracilariopsis, all of which are used for food, and Gelidium, Pachymeniopsis, and Ecklonia which are used as raw material for phycocolloid extraction. Significant work has gone into developing more productive strains of key seaweed species, and in 2012 the Korean government began to certify seaweed varieties. To date, 19 seaweed cultivars have been registered including 13 Pyropia, 5 Undaria, and 1 Saccharina. The industry is now seeking not only to increase productivity but also to add value through processing. Convenience foods and snacks have been developed that target health-conscious consumers and utilize the nutritional properties of seaweeds. The industry is also seeking to promote the sustainability of seaweed farming. One seaweed company in Korea obtained the world's first ASC-MSC (Aquaculture Stewardship Council-Marine Stewardship Council) certification in 2019 and more are expected to follow their lead. With continued research support, the Korean seaweed industry plans to continue to expand to meet new market demands at a sustainable pace.

• Fisheries and Aquatic Sciences
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• v.6 no.1
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• pp.13-19
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• 2003

Genomic DNA from the muscle of marsh clam (Corbicula leana) from Gochang, Muan and a Chinese site was extracted to identify genetic differences and similarity by randomly amplified polymorphic DNAs-polymerase chain reaction (RAPD- PCR). Out of 20 primers, seven primers produced amplified fragments which were consistently polymorphic. A total of 1,246 amplified products were produced of which 530 were polymorphic $(42.5\%)$. The number of polymorphic bands produced per primer varied from 40 to 122 with an average of 75.7 in marsh clam from Gochang. 3.28 of the 23.0 polymorphic bands per lane were found to be polymorphic. Also, about $4.34\%$ of total polymorphic bands were specific to marsh clam from Gochang. The major common bands of 0.28 kb generated by primer OPB-15 (GGAGGGTGTT) were present in every individuals, which were polymorphic. This common bands in every individuals should be diagnostic of specific strains, species and/or their relatedness. Primer OPB-19 (ACCCCCGAAG) produced the highest number of 12 specific bands. The intra-population variation was revealed in the band patterns identified by this primer. The random primer OPB-12 (CCTTGACGCA) yielded the amplified fragments which were consistently polymorphic between the marsh clams from Gochang and from Muan. This primer produced a total of 77 polymorphic bands: 31 bands from Gochang, 14 from Muan and 32 from the Chinese populations. An average of polymorphic bands were 1.8 from Gochang and 2.5 from the Chinese populations. This value obtained from the Chinese population was higher than those from the two domestic populations. Generally, the RAPD polymorphism generated by these primers may be useful as a genetic marker for strain or population identification of marsh clam.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.589-597
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• 2010

Monthly changes in the proximate and fatty acid compositions of chub mackerel (Scomber japonicus) muscle during cultivation from October 2007 to September 2008 were investigated. The lipid content increased gradually from the first stage of cultivation until March 2008 and then dramatically until May, before decreasing. The highest lipid content during cultivation was 21.6% in May, just before the fish spawns. There was a negative correlation (y=-1.1585x+87.741, $R^2$=0.9495) between the lipid and moisture contents during cultivation of chub mackerel. By contrast, the protein ($18.6{\pm}1.05%$) and ash ($1.18{\pm}0.11%$) contents were essentially unchanged during cultivation. Prominent fatty acids in chub mackerel muscle were 16:0, 18:0, 14:0 saturates, 18:1n-9, 16:1n-7, 18:1n-7 monoenes, and 22:6n-3 (docosahexaenoic acid, DHA), 20:5n-3 (eicosapentaenoic acid, EPA), and 18:2n-6 polyenes. The percentages of n-3 polyunsaturated fatty acids (PUFA), such as DHA and EPA, were higher during three months in the early stage of cultivation than they were subsequently. However, the PUFA (DHA+EPA) content (in mg/100 g of muscle) was lower in the early stage (740-796 mg/100 g muscle) than in the other stages. The highest PUFA (DHA+EPA) content was from April to May (2,749-2751 mg/100 g muscle). The PUFA content was positively correlated with the total lipid content of chub mackerel muscle during cultivation. The results indicate that cultured chub mackerel is a very good source of n-3 PUFA, such as DHA and EPA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.469-476
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• 2018

The purpose of this study was to collect basic data that could be used in the manufacture of two kinds of canned oyster Crassostrea gigas. The steamed oyster was prepared by shucking after boiling for 6 min at $105^{\circ}C$ and then washing and dewatering. The roasted oyster was prepared by baking steamed oyster at $140^{\circ}C$ for 20 min. The manufacturing methods of canned seasoned boiled oyster and canned seasoned roasted oyster were as follows. The boiled or roasted oyster (50 g) was added to a can (RR-90) along with a mixture of seasoning sauce 40 and then seamed using a vacuum seamer under 20 cm Hg after pre-exhausting at $90^{\circ}C$ for 20 min. The two kinds of canned oyster products produced under sterilization of Fo 12 min were tested for cultured bacteria, external appearance, proximate composition, pH, VBN (Volatile basic nitrogen), TBA (Thiobarbiuric aicd) value, amino-N, salinity, color value sensory evaluation, etc. Results showed that the canned seasoned roasted oyster had higher overall acceptability than the canned seasoned boiled oyster. The reason for this was judged to be that the process of roasting at $140^{\circ}C$ for 20 min influenced the sensory evaluation.

• Journal of Aquaculture
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• v.1 no.2
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• pp.121-133
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• 1988

Strongylocentrotus pulcherrimus is one of the very important fishery stock in this country since its high demand for raw gonad. Although the demand has been continuously increasing, the natural stock of this species seems to be decreasing. Since fresh macroalgae are not always available, the substitution of terrestrial vegetables for algae as a principal food was examined for the intensive indoor culture of the sea urchin. The results from the studies on selective and non-selective feeding habits and nutritional efficiencies using 13 food stuffs (6 macroalgae, 5 vegetables and 2 animal products) indicate that algae can be substituted with vegetables in sea urchin culture. Although the growth of body weight was the highest when sea urchins were fed Undaria Pinnatifida, the gonad index of the sea urchins fed on spinach, radish leaf and lettuce was higher than that of this brown alga. Considering the different food efficiencies of body and gonad growth, spinach and radish leaf will be adequate during gonad growth season, while lettuce and Chinese cabbage will be suitable for test growth season. In particular, radish leaf, which is usually not eaten by humans, could be highly beneficial and very economical in the sea urchin culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.217-221
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• 1975

This study was carried out to evaluate the sanitary quality of Jarhi-dom, Chromis notatus, and its products, during the period from May to October, 1975. And bacterial density of the sea water in the estuary of Sogwipo was compared. The number of general bacteria and coliform group in the sea water appeared lower than that of other areas. Both Jarhimuchim-hoe and Jarhimul-hoe showed higher bacterial densities than the fresh fish when caught and sold in the market although Jarhimuchim-hoe showed slightly higher density than Jarhimul-hoe. Vibrio parahaemolyticus was detected in some samples of sea water and Jarhi-dom, but it was not regarded for food poisoning. Bacterial densities in total plate counts, coliform group and Vibrio parahaemolyticus was highest in August and September.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.202-213
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• 1985

The protein nutritional quality of foods has become an important factor to food processors with the advent of nutritional labeling regulations for foods. Then, as is true today, the officially approved assay for protein nutritional quality was the rat based protein efficiency ratio(PER) bioassay. The PER bioassay requires a minimum of 28 days to performe, and is therefore not applicable to routine quality assurance use by the food industry. Within the past ten years there has been a research emphasis placed on the development of rapid, inexpensive, biological and/or chemical based assays for protein nutritional quality. It was hoped that if a rapid assay could be developed and thoroughly tested, it could be used in lieu of the PER bioassay in the day-to-day quality assurance screening of food ingredients and products. The rapid assays developed in the hope of attaining this goal have been based on microorganisms, proteolytic enzymes, and amino acid profiles, as well as combinations of the above. In this review, it will be described and briefly discussed many of procedures which had contributed conceptually as well as practically to the development of in vitro methods for the evaluation of protein quality. Special emphasis will be placed on the C-PER(computed protein efficiency ratio) assay which combines data from in vitro protease digestion and amino acid composition to predict protein nutritional quality designed by Satterlee et al. (1980), and the DC-PER(discriminant computed PER) which is a method of estimating protein quality based on rat assay and in vitro digestibility obtained using solely essential amino acid data will be also introduced.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.351-361
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• 2018

This study investigated the potential of collagenous protein fractions (CPFs) as functional foods. The specific CPFs studied were recovered from the roe of bastard halibut (BH), Paralichthys olivaceus; skipjack tuna (ST), Katsuwonus pelamis; and yellowfin tuna (YT), Thunnus albacares through the alkaline solubilization process at pH 11 and 12. The buffer capacity, water-holding capacity and solubility of CPFs with pH-shift treatment were significantly better at alkaline pH (10-12) than at acidic pH (2.0). At pH-shift treatment (pH 2 and 12), the foaming capacities of CPFs from ST and YT were improved compared to those of controls, but they were unstable compared to BH CPFs. The emulsifying activity index (EAI, $m^2/g$ protein) of CPFs (controls) was 16.0-21.1 for BH, 20.1-23.9 for ST and 9.3-13.7 for YT (P<0.05). CPFs adjusted to pH 12 showed improved EAI and YT CPFs showed significantly greater emulsifying ability than those from BH and ST. CPFs recovered from fish roe are not only protein sources but also have a wide range of food functionalities, confirming the high availability of fish sausage and surimi-based products as protein or reinforcing materials for functional foods and alternative raw materials.