• Food Science and Preservation
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• v.21 no.3
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• pp.381-387
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• 2014

Food irradiation is one of the successful modern techniques used to preserve food. However, it needs very careful control. Detection of irradiated food is of prime importance to facilitate global trade and consumer assurance, choice, and protection. This study was performed to evaluate the radiation-induced hydrocarbon content of dried squid and octopus by e-beam irradiation. The samples were collected from supermarkets all over South Korea and irradiated with an e-beam at 0, 1, 3, 5, 7, and 10 kGy doses. Lipids were extracted with soxhelt, and the hydrocarbons induced with irradiation were separated via solid phase extraction (SPE) and identified via gas chromatography mass spectrometry (GC/MS). The major induced hydrocarbons in the irradiated dried squid and octopus were 1-tetradecene and pentadecane derived from palmitic acid and 1-hexadecene and heptadecane from stearic acid. The concentration of hydrocarbons differed from the composition of the fatty acid at the same radiation and increased according to the level of the radiation dose. The hydrocarbons induced by e-beam irradiation, including 1-tetradecene, 1-hexadecene, and heptadecane, were confirmed to have been the irradiation marker compounds. Therefore, they can be used to distinguish the e-beam-irradiated dried squid and octopus from the non-irradiated ones.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.520-529
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• 2014

Experiment was set up to analyze bycatch and discards situation including snow crap Chionoecetes opilio of whelk trap. Four types of trap were used: drum type trap with PE net; drum type trap with PBS net; cylinder type trap with PE net; and cylinder type net with PBS net. Three funnels were attached in drum type trap and two funnels were used in cylinder type trap. A fleet of traps was consisted with one hundred traps. 25 traps of each type were set on a line in repeated sequence. Field experiments were conducted with 6 fishing operations in the Uljin waters, East Sea in July 2014. Catch of target whelks were 173,261 g and catch rate was 48.7% of total catch, while bycatch were 182,571 g, 51.3% of tatal catch. The catch rate of bycatch was 2.6% higher than that of target catch. Bycatch weight of snow crap was the highest as 142,987 g and formed about 40.2% of total catch, followed giant octopus, Enteroctopus dofleini, 31,762 g (8.9%). Bycatch rate of cylinder type trap was 2.3 times higher than that of drum type trap. Discard rate (discard/(discard+landing)) was 43.6%. Discard rate was the highest at cylinder type trap with PBS net as 63.1%, followed cylinder type trap with PE net as 47.9%, drum type trap with PE net as 33.4%, the lowest at drum type trap with PBS net as 22.1%.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.43-50
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• 2015

In this study, single PCR and multiplex PCR tests were examined for identification of four types of squid species (giant squid, cuttlefish, octopus, beka squid) purchased from fish market as well as aquatic processed products in Busan. To design the specific primers against each species, the nucleotide sequences of the mitochondrial 16s rRNA gene of Architeuthis dux, Todarodes pacificus, Enteroctopus dofleini, Enteroctopus megalocyathus, Uroteuthis chinensis, Uroteuthis duvauceli, Uroteuthis edulis groups were analyzed for the identification of each species registered in the GeneBank (www.ncbi.nlm.nih.gov) and have been used for comparative analysis. In order to obtain the size variation of amplified fragments on multiplex PCR, we designed KOJ-F, OJ-F, OCT-F, HAN-F, ALLR primers for each species. The optimal PCR conditions and primers were selected for four types of squid species to determine target base sequences in its PCR products. In the case of single PCR, giant squid was only amplified by KOJ-F/ALLR primer; cuttlefish was only amplified by OJ-F/ALLR primer; octopus was only amplified by OCT-F/ALLR primer; and beka squid was only amplified by HAN-F/ALLR primer. For multiplex PCR, the mixture of four kinds of genomic DNA (giant squid, cuttlefish, octopus, beka squid) been prepared as a template and used together with the mixture of KOJ-F/OJ-F/OCT-F/HAN-F/ALLR primers in the reaction. By the multiplex PCR, it is confirmed that four samples are correspond to multiple simultaneous amplicon. Finally, we validated the established methods of multiplex PCR in the aquatic processed products. Although the mitochondrial 16s rRNA primers used in this study was useful as a marker for detection of each species among them, the study indicated that the established multiplex PCR method can be more useful tool for monitoring the processed products.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.87-91
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• 2003

Experimental fishing was carried out to investigate the survival rate of fishes discarded after hauling from the trawl and to develop the fishing gear and method for fisheries management which can improve the survival rate of young fishes escaped from the trawl codend in offshore korean southern sea and off Cheju Island of Korea. The young fishes were bred in fish cage on the board to measure the sustainable survival time for fishes escaped from grid panel and codend. The obtained results are summarized as follows' 1. Japanese flying squid(Todarodes pacjficus), mitra squid(Loligo chinesis), hair-tail( Trichiurus lepturus), john dory(Zeus japonicus), spanish mackerel(Scomberomorus niphonius), redlip croaker (Pseudosciaena polyactis) and blackthroat seaperch(Doederliinia berycoides) were dead instantly after hauling. 2. Survival rate of tiger shark(Galeocerdo cuvier), conger eel (Conger myriaster), red skate (Dasyatis akajei), black scraper(Navodon modestus) and japanese fan lobster(Ibacus ciliatus) might be high after discarding because they survived for long hours in fish cage. 3. Blotched eelpout(Zoarces gili) escaped from the escapement device(grid) was dead within 6 hours in the water tank installed on the board but 97% of tiger shark and 72% of conger eel survived over 72 hours. 4. Red skate escaped from trawl codend was dead within 60 hours in the water tank installed on the board but sustainable survival time of 25% of octopus(Paroctopus dofleini) and 100% of black scraper was over 72 hours. 5. Compared with the survival rate of rosefish(Helicolenus higendorfi) escaped from the escapement device(grid) and trawl codend, all of the rosefish escaped from the grid was dead within 7.2 hours but 8.3% of the rosefish escaped from the codend survived over 72 hours. 6. In comparison with the survival rate of japanese fan lobster survived over 72 hours, survival rate of japanese fan lobster escaped the codend was much higher as 75% than 33% of japanese fan lobster escaped from the grid.