• The Journal of Fisheries Business Administration
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• v.40 no.2
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• pp.27-48
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• 2009

The objective of this paper is to estimate consumer's marginal willingness to pay(MWTP) for cold chain system attributes of mackerel using choice experiment questionnaires. The survey data were analyzed by conjoint analysis method with multinominal logit model. The five cold chain system attributes with $2{\sim}4$ attribute levels were considered : low temperature safekeeping of fishing boats, a kind of transport truck and packing box, using degree of low temperature facility in distribution, mackerel price per fish(1kg). At least 827 people were asked to participate in the survey. The major findings and implications of this study can be summarized as follows : The estimated multinominal logit model is statistically significant and the total consumers willingness to pay for the improved cold chain system attributes is 6,476 won (per kg). Compared with the base price(2,500 won/kg), the estimated MWTP is 2.5 times higher than the base price. Therefore, the consumer has a willingness to pay for the fresh and safe fish products, even though more money is paid. To satisfy the consumer's needs, cold chain system is necessary in point of long-term. In this reason, The government's policy support is needed for promoting cold chain system in fishery, and a master plan should be prepared.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.933-938
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• 1994

A study was amino acid contents by heating conditions of mackerel, pacific saury , yellow croaker, and brown sole investigated. In fresh fishes, total amino acid contents showed higher amount in brown sole and yellow croaker, than those of pacific saury and mackerel. The amino acid contents among the tested samples were higher Glx , leucine, lysine and arginine in order. During heating of samples the amino acid contents decreased. There appeared to be a proportional relationship of the heating temperature to decrease of amino acid. The amino acid contents of steamed samples significantly decreased than those of others. During warming and rewarming samples after storage at 4$^{\circ}C$ for 24 hours , amino acid contents slightly decreased.

• Journal of Marine Bioscience and Biotechnology
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• v.3 no.1
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• pp.1-6
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• 2008

Angola has a coastline of about 1,650 km long. Two diverging current namely, the Angola current with its warm water from the north and the cold Benguella Current in the south create a strong up-welling with a high productive ecosystem for marine resources. The area from Lobito to the mouth of the Cunene River, also known as the Southern fishing zone is by far the most productive of Angola's fishing zones. In 1977, the total potential of its marine fisheries sector was estimated at more than 700,000 tonnes per annum. In 2003, the Total Allowable Catch (TAC) established for demersal species was 57,600 tonnes and 160,000 tonnes for pelagic species. The most important resources are various marine demersal and pelagic fish including pilchard and the Cape and Cunene horse Mackerel (Tranchurus capensis and T. trecae). Sardinellas (Sardinella aurita and S. maderensis) are fished in parallel with horse mackerel. The rest of the catches are mainly demersal spp. and some deep water crustaceans. The demersal sppecies consist of Hake (Merluccius polli and M. capensis) and the large eye dentex spp. Tunas are caught at certain times of the year whilst some marine shrimp are also harvested from the Angolan waters. Angola also has several high value freshwater fish species, exploited by about 255 fishers. Tilapia sp. is among the most important and abundant fresh water fish found in Angola. Other species include the catfish (Clarias gariepinus) and fresh water prawns (Macrobrachuin rosenbergii). Some aquaculture ponds have been established in the country side, but due to lack of investment, proper training and the impact of civil war have seriously limited developments in the sub sector.

• The Journal of Fisheries Business Administration
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• v.41 no.3
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• pp.59-78
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• 2010

This paper tries to apply the asymmetrical price transmission(APT) behavior observed in the agricultural industry to supply chains of the domestic fishery industry by a statistical manner. The fore mentioned asymmetrical price transmission refers to when price movements in the later stage of the supply chain do not move in a normal or symmetrical manner corresponding to price movements in the earlier stage of the supply chain. Therefore, when the earlier stage price increase and the later stage price increases to a larger degree, it is called positive(+) asymmetry and the opposite behavior is called negative(-) asymmetry. The study examines the data from domestic producers of three fresh fish types, hairtail, mackerel, and cuttlefish, and tries to examine the price asymmetry between the producer or farm, wholesaler, and retail prices via an APT test utilizing unit root, cointegration, and error correction model. The study found, hairtail wholesale and retail pricing bas a negative asymmetric relationship while mackerel has a negative asymmetric pricing relationship at the producer and retail levels of the supply chain. In the case of cuttlefish, all levels of the supply chain showed negative asymmetrical behavior in the supply chain price transmission, meaning the earlier stage price changes are more rapidly and greatly inputted in the later stage of the supply chain pricing. We believe that the reason why the analysis results show negative price asymmetry is due to the uniqueness of fishery products having an important variable such as freshness. If price increases are greater and quicker than price decreases, then consumer demand, which is sensitive to price increases will decrease and subsequently result in the increase of inventory levels, reducing profits for retailers. Also, frozen hairtail, mackerel, and cuttlefish will act as substitute goods to fresh fishery products. Therefore, fresh fishery products have a high demand of price elasticity. When prices increase, demand quickly decreases. Therefore the profit of wholesalers and retailers to decrease, I think this is the main reason of APT in the supply chain of Korea' s fisheries industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.115-120
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• 1974

Secondary amines are known as one of the precursors of nitrosamines which are potent carcinogenic compounds of man and animals. Nitrosamines are formed when both secondary amines and nitrite are present. The nitrites are occurred naturally in vegetables, fruits and many others, and frequently used in fish product as a color fixative or a preservative. In this paper, to know the formation of nitrosamines in fish meat, the changes of dimethylamine (DMA) content during the heat treatment such as drying, roasting and fish cake processing are discussed. The results showed that generally DMA increased considerably during heat processing. During drying, DMA in cuttle fish increased 16 times higher, while in Alaska pollack doubled than the fresh. In the roasted mackerel, the DMA content appeared 6 times higher than the fresh, while 9 times higher in canning. In fish cake from yellow corvenia, DMA increased 4 times higher than the fresh. On the contrary diethylamine and diphenylamine were not found in this experiment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.731-736
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• 2016

No freshness indicator for fish has yet been established. Thus, we investigated changes over time in mackerel quality in an effort to development useful indicators. Fresh whole mackerel Scomber japonicus were stored at $4^{\circ}C$ immediately after capture and quality changes were evaluated every 3 days for a total of 15 days. Whole fish were divided into ventral parts (VPs) and dorsal parts (DPs); we measured the trimethylamine (TMA) and volatile basic nitrogen (VBN) levels, pH values, and color values in/of these parts. The TMA and VBN levels tended to increase during storage and the TMA changes in VPs were higher than those in DPs. In particular, the VP TMA content attained a maximum of 3.68 mg/100 g at 6 days, and the VBN content attained a maximum of 20.88 mg/100 g at 9 days, suggestive of initial fish spoilage. The pH ranged from 5.99-6.17 over the first 3 days and from 6.17-6.38 from days 6-15. Surface color changes on VPs and DPs were explored. Significant decreases in both VP lightness and yellowness were evident after 3 days. The data suggest that both TMA level and lightness of the color are valuable indicators of freshness in the initial stage of mackerel retail.

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.115-121
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• 1995

Bacterial mutagenicity of shellfish or canned products of red-muscle fish affected by hot-airdry processings and/or during storages was investigated by Ames preincubation method. Mussel (Mytilus edulis) and surf clam (Tapes japonica) dried under either 40$\circ$C, 50$\circ$C or 60$\circ$C until remained about 25 % water content was stored at 4$\circ$C or 25$\circ$C for 6 months. Commercially available canned product of pacific saury (Cololabis saira) and mackerel saury (Scotnberjaponicus), whose producer or date of manufacture was identical each other, was stored at 25$\circ$C for 6 months. Mutagenic substances from sample (25 g dry weight) were extracted and purified for mutagenicity assay against S. typhitnurium TA98 by the simultaneous distillation extraction (SDE) method (Lee et al. 1955). Mutagenicity of sample was expressed number of revertant per 25 g dry sample. Number of revertant from unheated mussel sample was appeared to be 135, relative to 22 from unheated surf clam sample. Mutagenicity of both shellfish was strongly affected by heat treatment, but a lesser extent by storage conditions, even at 25$\circ$C for 6 months. Revertants of the mussel sample dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C was found to be 227, 779, and 883, respectively. Similar, but lower, mutagenicity was observed from the sample of surf clam dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C than mussel. Mutagenicity of canned pacific saury and mackerel samples was not influenced by storage conditions. Number of revertant from pacific saury was 175 which was relatively higher than 5 from mackerel. Mutagenicity of fresh pacific saury and mackerel samples was significantly higher than that of their counterparts from canned products. These results indicate that mutagenicity of the shellfish was affected by heat treatment (40$\circ$C, 50$\circ$C, or 60$\circ$C) used for drying process, but not much by storage for 6 months at 4$\circ$C or 25$\circ$C and the mutagenicity of canned products of red-muscle fish was not influenced by storage, even at 25$\circ$C for 6 months.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.708-713
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• 1997

Various chemical indices were analyzed to clarify the tendency of rancidity during the repeats of heating so called roasting heating and/or reheating in dark muscled fish (mackerel and pacific saury). The total lipid contents of fresh mackerel and pacific saury were $36.7\%\;and\;28.4\%$ in saturated fatty acid, $33.0\%\;and\;20.2\%$ in monoenoic acid, and $29.9\%\;and\;49.7\%$ in polyenoic acid, respectively. The ratios of unsaturated fatty acid (UFA)/Saturated fatty acid (SFA) were 1.7, 2.5 and content of total lipid was $16.5\%\;and\;13.7\%$, respectively. Peroxide content gradually increased after roasting heating and reheating in mackerel while it decreased after reheating in pacific saury. Thiobarbituric acid value also increased during roasting and heating in all the samples but decreased after reheating. Acid value increased after roasting heating and reheating in all samples, particularly it was high in pacific saury which have a high composition of UFA. More conjugated dienes were formed when the meat was roasted at $180^{\circ}C$ than at $200^{\circ}C\;or\;220^{\circ}C$, and in the filet with skin than the skinless.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.1
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• pp.36-41
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• 1987

In the refrigerated storages of fishery products, the lipid oxidation of the meats had been the major deterioration factor. For the effective utilization of mackerel, Scomber japonicus, and yellow corvenia, Pseudosciaena manchuria, which are major costal fish in Korea, and were studied about oxidative rancidity during the refrigerated storage at $-18^{\circ}C$ and the effect of different temperatures upon the cooked meat. We detected the results followed. 1. The Induction period of refrigerated storages had 20 days for fresh meat and 60 days for cooked meat. 2. Peroxide and TBA value of cooked meats had half amount values In the comparison with those of fresh meats, 3. Values of mackerel had double amount than those of yellow corvenia in peroxide and TBA value as if the different values come from different fish species, 4. The rancidative degree of the different temperatures on the samples had the least amount at $-5^{\circ}C$ among several kinds of storage temperatures.

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