• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.4
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• pp.355-362
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• 1989

For the effective utilization of mackerel as a food sauce, the processing conditions of the frozen seasoned mackerel meat and the changes in taste compounds during its frozen storage were investigated. To prepare the frozen seasoned mackerel meat, the mackerel was headed, gutted manually, washed with tap water and deboned with the meat seperator. Then it was mixed with additives such as emulsion curd(32.1%, w/w), table salt(0.5%, w/w), sugar(2.0%, w/w), sodium bicarbonate(0.4%, w/w), polyphosphate(0.2%, w/w), monosodium glutamate(0.2%, w/w), onion powder(0.3%, w/w), garlic powder(0.1%, w/w), ginger powder(0.1%, w/w), soybean protein(3.0%, w/w) and sodium erythorbate(0.1%, w/w). This seasoned fish meat was frozen with contact freezer, packed In a carton box, and then stored at $-25^{\circ}C$. The moisture and lipid contents in the products were 70.8-71.7% and 10.9-11.3%, respectively. The taste compounds of the frozen seasoned mackerel meat were free amino acids(1625.0-1692.0mg/100g), nucleotides and their related compounds(316.6-366.8 mg/100g) as well as total creatinine(270.2-311.8 mg/100g), and small amount of betaine and TMAO. In free amino acids, the predominant ones were histidine, lysine, glutamic acid and arginine. It was supposed from the results that principal taste compounds of frozen seasoned mackerel meat were free amino acids, and that total creatinine, TMAO, TMA and betaine as well as nucleotides and their related compounds also played an assistant role.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.625-639
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• 2019

Microplastics are one of the substances threatening the marine ecosystem. Here, we summarize the status of research on the effect of microplastics on marine life and suggest future research directions. Microplastics are synthetic polymeric compounds smaller than 5 mm and these materials released into the environment are not only physically small but do not decompose over time. Thus, they accumulate extensively on land, from the coast to the sea, and from the surface to the deep sea. Microplastic can be ingested and accumulated in marine life. Furthermore, the elution of chemicals added to plastic represents another risk. Microplastics accumulated in the ocean affect the growth, development, behavior, reproduction, and death of marine life. However, the properties of microplastics vary widely in size, material, shape, and other aspects and toxicity tests conducted on several properties of microplastics cannot represent the hazards of all other microplastics. It is necessary to evaluate the risks according to the types of microplastic, but due to their variety and the lack of uniformity in research results, it is difficult to compare and analyze the results of previous studies. Therefore, it is necessary to derive a standard test method to estimate the biological risk from different types of microplastics. In addition, while most of the previous studies were conducted mostly on spheres for the convenience of the experiments, they do not properly reflect the reality that fibers and fragments are the main forms of microplastics in the marine environment and in fish and shellfish. Furthermore, studies have been conducted on additives and POPs (persistent organic pollutants) in plastics, but little is known about their toxic effects on the body. The effects of microplastics on the marine ecosystems and humans could be identified in more detail if standard testing methods are developed, microplastics in the form of fibers and fragments rather than spheres are tested, and additives and POPs are analyzed. These investigations will allow us to identify the impact of microplastics on marine ecosystems and humans in more detail.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.166-181
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• 2020

The egg development, early life history and spawning site characters of Korean endemic fish, Coreoleuciscus splendidus (Gobioninae), were investigated at the part of Jo-jong stream in Korea from May 2020. The fertilized eggs were 2.05~2.23 mm (mean, 2.13 mm) in diameter and had no oil globules. The embryo began to hatching about 98 hrs after fertilization under water temperature of 20±1℃. The newly-hatched larvae were 5.03~5.68 mm (mean, 5.31 mm) in total length (TL), and their mouth and anus were not opened. 4 days after hatching, Several rod-like cupulae were observed on the head and lateral side of the body at 6.95~7.89 mm (mean, 7.51 mm). 7 days after hatching, the post-larva stage were 8.39~9.29 mm (mean, 8.78 mm) in total length, and their york were completely absorbed. The cupulae were completely distinguished. They entered the juvenile stage when all fin-rays were formed at 29 days after hatching, and their TL were 14.16~17.04 mm (mean, 14.99 mm). Squamation was initiated on the caudal body at approximately 18.21~23.74 mm (mean, 30.28 mm), 38 days after hatching, and completed at 26.82~33.33 mm (mean, 19.42 mm), 73 days after hatching, the external characteristics from of juveniles were same to adults. The spawning site was characterized by bottom structure of pebble (64~16 mm) and gravel (16~2 mm), environmental conditions of the spawning sites were 6~18 cm in water depth, 0.43~0.73 m/sec in bottom water velocity. In spawning sites, an egg mass or separated eggs were located a small gap of under the pebble and gravel.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1135-1141
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• 1996

In order to investigate the composition and the actual status of extractive nitrogenous compounds in saeujeot, a salted and fermented seawater shrimp(Acetes japonicus), the extract was analyzed separately into extractive nitrogen, free amino acids, oligpopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds, using specimens collected at fish markets from July in 1994 November in 1995. The extractive nitrogen of saeujeot was ranging from 430 mg to 528 mg, and the total of free amino acids in it was ranging from 1,509 mg to 2,131 mg, The extract was rich in free amino acids especially in lysine, glutamic acid, leucine, arginine, glycine, histidine, and glutamine, However, the content of most free amino acids was fluctuated from collection to collection. The total of nucleotides and related compounds in the extract was ranging from $1.38\;{\mu}mol\;to\;7.41\;{\mu}mol$, and the rage of fluctuation was essential identical with those of the extractive nitrogen and free amino acids. Homarine, trigonelline, ${\beta}-alaninebetaine$, and glycinebetaine were found in the saeujeot extract. Among them, homarine was the most abundant, ranging from 97 mg to 224 mg, but trigonelline, ${\beta}-alaninebetaine$, and glycinebetaine were very low. TMAO and TMA in the saeujeot extract were $13{\sim}80\;mg\;and\;12{\sim}280\;mg$, respectively. A small amount of creatine (less than 6 mg) and creatinine (less than 1 mg) was detected in all samples.

• Food Science and Preservation
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• v.19 no.3
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• pp.376-384
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• 2012

This study was conducted to investigate the food purchasing management of school food services. The subjects consisted of 271 school dietitians in the Daegu and Gyeongbuk area. The percentages of ready-to-use vegetables actually being used were as follows: root of balloon flowers, 88.4%; garlic, 87.8%; blanched bracken, 80.1%; raw lotus root, 65.7%; burdock, 63.5%; small green onion, 63.5%; stem of taro, 57.6%; ginger, 35.1%; radish root, 30.6%; blanched asterscaber, 29.2%; large type welsh onion, 25.8%; carrot, 25.5%; onion, 21.4%; and potato, 8.9%. The percentages of HACCP-certified products being used were as follows: meat, 75.9%; eggs, 66.7%; soybean curds, 65.5%; ready-to-use seafood, 55.1%; starch jellies, 49.9%; spice, 44.9%; kimchi, 30.9%; ready-to-use vegetables, 22.7%; and fruits, 6.9%. The percentages of environment-friendly food items being used were as follows: eggs, 31.0%; meat, 28.7%; soybean curds, 22.1%; and fruits, 17.7%. Of these food items, meat and ready-to-use seafood were being used the most in the elementary schools. The percentages of imported food items being used were as follows: starch jelly, 29.2%; ready-to-use seafood, 24.7%; soybean curds, 20.5%; spice, 15.9%; and fruits, 10.1%. The food items requiring HACCP certification were as follows: beef and pork, 81.5%; chicken, 80.1%; ready-to-use seafood, 78.6%; frozen dumplings, 73.8%; soybean curds, 71.6%; peeled eggs, 70.8%; fish paste, 69.4%; starch jelly, 65.7%; milk, 63.1%; kimchi, 54.6%; spice, 50.6%; frozen noodle, 45.4%; ready-to-use vegetables, 44.3%; and bean sprouts, 29.5%. It was confirmed that 8.1% of the sanitation monitoring results were intentionally misreported. Therefore, to supply good and safe foods to schools, active management is needed in schools and food manufacturing and delivery companies.

• Food Science and Preservation
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• v.16 no.5
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• pp.705-713
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• 2009

We prepared salmon patties and compared the quality characteristics thereof with those of commercial tuna and pork patties. The moisture and crude ash contents of salmon patty were lower, whereas the crude protein content was higher, than those of commercial patties. The crude lipid content of salmon patty was higher than that of tuna patty, but lower than that of pork patty. The pH value and the volatile basic nitrogen content of salmon patty were lower than those of the commercial patties. Hunter color values (L, a, b) in a cross-section of cooked salmon patty were higher, whereas the ${\Delta}E$ value was lower, than those of the two commercial patties. The lipophilic browning index (0.397) of salmon patty was higher, whereas the hydrophilic browning index (0.047) was lower, than those of commercial patties. Trichloroacetic acid-soluble N content (272 mg/100 g) of salmon patty was lower than of commercial patties. The major fatty acids of salmon patty were palmitic acid (11.9%), oleic acid (27.6%), and linoleic acid (30.1%), whereas small amounts of eicosapentaenoic acid (EPA, 3.7%) and docosahexaenoic acid (DHA, 8.4%) were also found. The predominant amino acids of all patties were arginine, glutamic acid, aspartic acid, leucine, threonine, and proline, and the contents of these amino acids in salmon patty were higher than in the two commercial patties. The Fe, Ca, K, P, and Mg contents of salmon patty were 2.4 mg/100g, 42.6 mg/100g, 207.5 mg/100g, 211.6 mg/100 g, and 29.9 mg/100 g, respectively. The sensory quality of salmon patty was higher than that of pork patty. These results indicate that salmon patty may have good quality characteristics, comparable to those of the two commercial patties.

• Food Science and Industry
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• v.51 no.4
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• pp.278-301
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• 2018

Although more than 80% of living organisms are found in marine ecosystems, only less than 10% of marine resources have been utilized for human food consumptions and other usages. It is well known that marine resources (fish, shellfish and algae) have exceptional nutritional properties; however, their functional characteristic has not been completely discovered. It is believed that metabolites (organic compounds, proteins, peptides, lipids, minerals, etc.) play an important role to show its biological properties. Marine proteins and peptides are considered to be future drugs due to their excellent biological activities with a fewer adverse side effect. Marine peptides show several biological activities, including antimicrobial, antioxidant, anti-inflammatory, anti-cancer, anti-viral, anti-tumor, anti-diabetic, anti-hypertensive, anti-coagulant, immunomodulatory, appetite suppressing and neuroprotective effects. Therefore, the pharmaceutical, nutraceutical, and cosmeceutical companies have been paid attention to the marine peptides to commercialize into products. This current review mainly focused on the above mentioned biological activities of marine peptides and protein hydrolysates as a functional food and pharmaceutical applications. To commercialize these materials in industrial level required large quantity in high-purity level, and it is complicated to produce huge quantity from the marine resources due to insufficient raw materials, unavailability of raw materials through a year, hinder the growth with geographical variations, and availability of compounds in extreme small quantities. The best solution for these issues is to introduce new modern technologies such as artificial intelligence robots, drones, submersibles and automated raw material harvesting vessels in farming industries instead of man power, which will lead to 4th industrial revolution.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.268-286
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• 2018

The eutrophication and algal blooms by harmful cyanobacteria (CyanoHAs) and freshwater redtide (FRT) that severely experiencing in typical regulated weir system of the Nakdong River are one of the most rapidly expanding water quality problems in Korea and worldwide. To compare with the factors of rainfall, hydrology, and dominant algae, this study explored spatiotemporal variability of the major water environmental factors by weekly intervals in eight weir pools of the Nakdong River from January 2013 to July 2017. There was a distinct difference in rainfall distribution between upstream and downstream regions. Outflow discharge using small-scale hydropower generation, overflow and fish-ways accounted for 37.4%, 60.1% and 2.5%, respectively. Excluding the flood season, the outflow was mainly due to the hydropower release through year-round. These have been associated with the drawdown of water level, water exchange rate, and the significant impact on change of dominant algae. The mean concentration (maximum value) of chlorophyll-a was $17.6mg\;m^{-3}$ ($98.2mg\;m^{-3}$) in the SAJ~GAJ and $29.6mg\;m^{-3}$ ($193.6mg\;m^{-3}$) in the DAS~HAA weir pools reaches, respectively. It has increased significantly in the downstream part where the influence of treated wastewater effluents (TWEs) is high. Indeed, very high values (>50 or $>100mg\;m^{-3}$) of chlorophyll-a concentration were observed at low flow rates and water levels. Algal assemblages that caused the blooms of CyanoHAs and FRT were the cyanobacteria Microcystis and the diatom Stephanodiscus populations, respectively. In conclusion, appropriate hydrological management practices in terms of each weir pool may need to be developed.

• Food Science and Industry
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• v.55 no.2
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• pp.188-202
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• 2022

In the insect industry, as the scope of application of insects is expanded from pet insects and natural enemies to feed, edible and medicinal insects, the demand for quality control of insect raw materials is increasing, and interest in securing the safety of insect products is increasing. In the process of expanding the industrial scale, controlling the temperature and humidity and air quality in the insect breeding room and preventing the spread of pathogens and other pollutants are important success factors. It requires a controlled environment under the operating system. European commercial insect breeding facilities have attracted considerable investor interest, and insect companies are building large-scale production facilities, which became possible after the EU approved the use of insect protein as feedstock for fish farming in July 2017. Other fields, such as food and medicine, have also accelerated the application of cutting-edge technology. In the future, the global insect industry will purchase eggs or small larvae from suppliers and a system that focuses on the larval fattening, i.e., production raw material, until the insects mature, and a system that handles the entire production process from egg laying, harvesting, and initial pre-treatment of larvae., increasingly subdivided into large-scale production systems that cover all stages of insect larvae production and further processing steps such as milling, fat removal and protein or fat fractionation. In Korea, research and development of insect smart factory farms using artificial intelligence and ICT is accelerating, so insects can be used as carbon-free materials in secondary industries such as natural plastics or natural molding materials as well as existing feed and food. A Korean-style customized breeding system for shortening the breeding period or enhancing functionality is expected to be developed soon.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.125-132
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• 2007

We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.