• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.5
• /
• pp.469-476
• /
• 1986

Proteolytic activity of the tissue extracts from the muscle of mackerel, Scomber japonicus, and sardine, Sardinops melanostcta, was comparence with referenced to the optimum reaction condition. Thermal stability and change of proteolytic activity of the tissue extracts during storage were investigated. The existence of acid, weak acid and alkaline proteinase was identified in the ordinary and dark muscle of the mackerel and sardine. Specific activity of acid proteinase was stronger than weak acid or alkaline proteinase in the both fish. The proteolytic activity of the tissue extracts on the optimum reaction condition was: ordinary muscle of mackerel, 0.12 nM-Tyr. eq./mg-prot. /min. at pH 3.0 and $50^{\circ}C$; dark muscle of mackerel, 0.36 nM-Tyr. eq./mg-prot. /min. at pH 3.0 and $45^{\circ}C$; ordinary muscle of sardine, 0.45 nM-Tyr. eq./mg-prot. /min. at pH 2.4 and $45^{\circ}C$; dark muscle of sardine, 0.24 nM-Tyr. eq./mg-port. /min. at pH 2.4 and $45^{\circ}C$. The proteinases distributed in the muscle of mackerel and sardine were stable with the heat treatment at $45^{\circ}C$ for 5 minutes, but those in the dark muscle of mackerel was stable with the treatment at $5^{\circ}C$ for 5 minutes. The proteinases from the muscle were slowly inactivated with the whole storage days at $5^{\circ}C\;and\;-15^{\circ}C$, those were more stable at $-15^{\circ}C\;than\;5^{\circ}C$ storage.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.67-72
• /
• 1998

As a part of basic investigation for utilizing by-products derived from seafood processing as a food source, a chemical characteristics of fish bones (cod bone, Alaska pollack bone, yellowfin sole bone, hoki bone, conger eel bone and mackerel bone) were investigated. The crude protein (40.7% on the dry basis) and collagen contents (5.86%, on the dry basis), imino acid composition (189 residues/1,000 residues) of hoki bone were higher than those of the other fish bones, but were lower than those of the animal bone. The crude lipid contents and EPA and DHA compositions of yellowfin sole, conger eel and mackerel bones were $22.8{\sim}43.9%$ on the dry basis and $15.6{\sim}23.8%$, respectively and were lower than those of squid viscera. The major ash components of the fish bones were found to be calcium and phosphorus and the contents in 100 g crude ash were $37.1{\sim}38.6%$ and $18.0{\sim}18.5%$ respectively. The calcium and phosphorus contents in 100 g crude ash of cod and Alaska pollack bones were more than those of the animal bones, as well as the others. It may be concluded, front these results, hoki bone can be effectively utilized as a processing materal of collagen or gelatin and cod and Alaska pollack bones as a calcium source.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.22 no.5
• /
• pp.219-227
• /
• 1989

A new devised conductivity meter was used in the rapid and convinient determination of freshness of fish meats. Electric conductivity of frozen fishes like cod, tuna, flounder, Alaksa pollock were demonstrated about $6,100\pm200{\mu}u$ at the beginning of spoilage showed VBN content of $30\~35mg\%$ while that of fresh meat of yellow tail, rock trout, and mackerel were in the range of $5,100\~5,400{\mu}u$. The relationship between electric conductivity and freshness as measured by VBN content was direct proportion during the deterioration of fish meat. It was presumed that electric conductivity change of red muscled fish was more temperature dependence than that of white muscled fishes. $Q_{10}$ value of mackerel meat was about 2.34 at the temperature ranged from 15 to $30^{\circ}C(\pm1^{\circ}C)$). The electric conductivity obtained with conductivity meter could be a valuable criteria for the freshness test of fish meat determining in 10 seconds by handy compact portable meter.

• Applied Biological Chemistry
• /
• v.39 no.5
• /
• pp.361-367
• /
• 1996

As a part of investigation for quality improvement of surimi gel from fish with a red muscle by addition of emulsion curd, we investigated the processing conditions of emulsion curd contained succinylated gelatin from conger eel skin as an emulsifier and emulsion curd-added surimi gel. Activity and stability of emulsion curd on standing at room temperature, chilled temperature and vibration were remarkably improved by the addition of 15 tunes of soybean oil and 5 times of water to succinylated gelatin from conger eel skin. The proximate composition of the emulsion curd was moisture 18%, protein 5%, lipid 76% and ash 0.5% and its appearance was white. Peroxide value and fatty acid composition of emulsion curd contained succinylated gelatin as an emulsifier were similar to these of soybean oil. By the addition of 6% of emulsion curd to mackerel surimi, gel strength, appearance and texture of the resulting surimi gel were improved, while its peroxide value and brown pigment revealed minor change. From the results of volatile basic nitrogen, viable cell counts and histamine content, the emulsion curd-added mackerel surimi gel can be safe In the sense of food sanitation.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.4
• /
• pp.471-476
• /
• 1998

Microbiological spoilage of marine fish is complex process occurring by bacteria, yeasts and molds. There have been rare study for saprophytic yeasts although having enormous numbers of bacteriological studies on the spoilage of marine fish. The 14 genera of yeasts isolated from mackerel (Scomber japonicus) with high frequency of occurrence were Candida sp., Rhodotorula sp., Torulopsis sp., Cryptotoccus sp. and Tricosporon sp. Among these ones Candida lipolytica was identified as the strongest proteolytic yeast, then named Candida lipolytica FM5 (C. lipolytica FM5). C. lipolytica FM5 showed optimum growth at $25^{\circ}C$, pH 7.0 and could grow at $5^{\circ}C$ and in medium containing $10\%$ sodium chloride, To evaluate the saprophytic activity of the selected strain, C, lipolytica FM5 and Pseudomonas fluorescens ATCC 17571 which is one of representative spoilage bacteria were individually inoculated into the sterilized fish muscle homogenates, and then pH changes and volatile basic nitrogen (VBN) values were checked during the storage at various temperatures. According to the experimental results, the productions of VBN by C. lipolytica FM5 in the fish muscle homogenates were 50 mg-N/100 g at $5^{\circ}C$, 152 mg-N/100 g at $15^{\circ}C$ and 379 mg-N/100 g at $25^{\circ}C$ for 1 week storage, respectively. Above results were nearly same as in case of Ps. fluorescens ATCC 17571 inoculation. It suggest that sapyophytic yeasts also have important role in spoilage of marine fish.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.1
• /
• pp.170-183
• /
• 2015

The objectives of this study is to analyze the competitiveness of fisheries trade between Korea and China, and to estimate strategic seafood export products for Korea-China FTA in fisheries sector. The results of analyses indicate that Korea has comparative advantages in export items such as spanish mackerel, flatfish, cod, roe in frozen fish(0303), and squid, sea cucumber, oyster in molluscs(0307). In addition, tuna in prepared or preserved fish(1604), sea cucumber in crustacean, molluscs and other aquatic invertebrates(1605) have comparative advantage in exporting to China.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.30 no.2
• /
• pp.131-139
• /
• 2024

In Korea, mackerel is the most preferred red fish commodity and has been increasingly consumed in chillstored fresh state rather than in frozen or salted fish. Modified atmosphere packaging (MAP) technology as a replacement of air with low O₂ and high CO₂ concentration gas was applied in this study to preserve its freshness. Four MAP conditions of CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) were compared in quality preservation effect with air package used as Control. Three hundred grams mackerel fillets packaged in gas barrier tray were stored for duration of 10 days at 5℃. Quality was assessed in total aerobic bacterial count, pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid-reactive substances (TBARS), peroxide value (POV), texture, and surface color. High CO₂ concentration MAPs (CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), and CO₂(60):O₂(0): N₂(40)) inhibited total aerobic bacteria growth in the fish fillets. MAPs of high CO₂ concentration with O₂ containment (CO₂(60):O₂(30):N₂(10) and CO₂(60):O₂(5):N₂(35)) showed a low TVB-N content through the storage. The treatments containing O₂ above 20% (Control and CO₂(60):O₂(30):N₂(10)) showed more accelerated increases in TBARS and POV than other treatments. The visual appearance was better for fillets in the packages of CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) than for those of other treatments. The MAPs of CO₂(60):O₂(5):N₂(35) and CO₂(60):O₂(0):N₂(40) are expected to be effective in keeping the freshness of mackerel fillets.

• Journal of Nutrition and Health
• /
• v.37 no.1
• /
• pp.38-44
• /
• 2004

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades and concerns about naturally occurring harmful contaminants of food. Although, irradiation provides an excellent safeguard for the consumer by destroying harmful bacteria, it would be necessary to investigate nutritional adequacy of irradiated foods with a special emphasis on such foods as red pepper powders, cold-water fishes (mackerel), sesame seeds that are widely consumed in Korea. These food items are of special concern due to the fact that most of them are imported and that several nutrients contained in them are sensitively reacting to irradiation. We observed changes in the antioxidant nutrients contents, such as vitamin A, $\beta$-carotene, vitamin C and total phenol, and also vitamin B$_1$ in the foods that were irradiated at different dose levels. The nutrients contents in red pepper were respectively 98.6% and 92.3％ for total phenol, and 97.8% and 94.5% for $\beta$-carotene, right after irradiation at the dose of 10 and 20 kGy. The vitamin C contents decreased with irradiation doses up to 76.4% (10 kGy) and 68.5% (20 kGy) and B$_1$ contents decreased to 54.9% and 80.7% of non irradiated red pepper. When the mackerel was irradiated at the applied dose of 3 and 7 kGy, total phenol concentration of the irradiated fish was respectively 91.3% and 94.2% of non irradiated fish. The amounts of vitamin A were 82.6% (3 kGy) and 78.0% (7 kGy) of unirradiated sample and vitamin B$_1$ contents reduced to 30.5% and 51.5%. $\alpha$-Tocopherol content was 33.9% of the non-irradiated one when it was irradiated at 7 kGy. Vitamin A and ${\gamma}$-tocopherol contents in sesame seeds linearly decreased with the applied doses (5 and 10 kGy) Vitamin A contents decreased up to 87.8% (5 kGy) and 82.9% (10 kGy) and that of ${\gamma}$-tocopherol were 72.4% and 66.5% of the unirradiated sample.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.5
• /
• pp.621-630
• /
• 2015

This study investigated the concentration of total mercury in 17 species of commonly consumed fishes and assessed the risk to human health from provisional tolerable weekly intakes PTWI% as affected by migratory characterization, such as migration and vagility. The measured mean concentrations of total mercury in these 17 species of commonly consumed fishes suggest that mean concentrations of total mercury in 10 species of migratory fishes (largehead hairtail, chub mackerel, Pacific saury, skipjack tuna, Pacific cod, anchovy, Alaska pollack, brown croaker, Japanese Spanish mackerel, yellow croaker and Pacific herring) were low compared to those in 7 species of demersal fishes (red stingray, brown sole, bastard halibut, conger eel, blackmouth angler, rockfish and filefish). Based on the mean concentrations, the PTWI% of total mercury among commonly consumed migratory fishes was 3.393%, which was higher than that of commonly consumed demersal fishes (2.710%).

• The Journal of Fisheries Business Administration
• /
• v.50 no.4
• /
• pp.29-44
• /
• 2019

This paper examines the trend of restructuring and direction of management response in the Large Purse Seine Fishery. The large-scale fishing industry is one of the most popular fishing areas in the coastal area, and it has been developed by providing exclusive supplies of many types of catchy fish, such as mackerel and horse mackerel through physical productivity in fleet operations. However, the Large Purse Seine Fishery has been declining in profitability due to the deterioration of the business environment since 2000. It is at a crossroads whether it will disappear or regenerate as it is. The Large Purse Seine Fishery's current problems are: firstly, the continued deterioration of the fishery business balance and worsening labor problems, secondly, insufficient freshness management and quality control after landing, and thirdly, import competition. The fourth is the intensification of the market competition, which is the evolution of fishing variability and the increase in the proportion of small fish. The fifth is the reduction of the operating fishing ground due to the suspension of mutual fishing in Korea and Japan. To address these problems and suggest management response directions for the survival of large-scale fishing businesses is as follows. First, a sustainable production system should be established through strengthening resource management and promoting international fisheries cooperation. Second, the profitability of fishing management should be improved by introducing a low-cost supplier system and securing a stable labor force. Third, we should improve the leading and quality control of catch, improve the high value-added value of catch through brand development, and secure competitive advantage with imported produce. Finally, the government should establish a cooperative system among private sector, government, and research institutes to push ahead with these tasks and strengthen the competitiveness of the front and rear industries.