• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.201-205
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• 2001

As a series of studies on improving the processing suitability of imported Pacific saury, oxidative stability of seasoned-dried Pacific saury treated with liquid smoke (T2 product) was examined during storage, comparing with control (C, seasoning only) and T1 (treatment of 0.05% BHT instead of liquid smoke). The pH of T2 treated with liquid smoke was relatively lower than those of C and T1 during storage. The contents of volatile basic nitrogen in all products increased continuously during storage. In the changes of TBA and POV of products during storage, the POV of T2 was lower than that of T1, and the TBA values of T1 and T2 were lower than that of C product. The major fatty acids were 22 : 1n-11, 20 : 1n-11, 16 : 0, 14 : 0, 22 : 6n-3, 20 : 5n-3, 18 : 4n-3, 16 : 1n-7, 14 : 1n-7 and 18 : 1n-9 in the both C and T2 products. The contents of polyunsaturated fatty acids in hath C and T2 somewhat decreased with increasing storage period, while those of saturated and monounsaturated fatty acids increased.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.861-869
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• 2020

This study was conducted to investigate the suitability of frozen oysters as a raw material for the preparation of seafood products by measuring the concentrations of harmful microorganisms and chemicals in thawed flesh. The microbial concentrations in thawed oysters were 2.3-5.0 log CFU/g for viable cell counts, not detected (ND)-1.0 log CFU/g for coliform bacteria, and ND for Escherichia coli and pathogenic bacteria such as Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Enterohemorrhagic Escherichia coli (EHEC), and Clostridium perfringens. In frozen oysters, the heavy metal concentration for viable cell counts was ND-0.030 mg/kg, for lead was ND-0.393 mg/kg, and for cadmium was 0.021-0.597 mg/kg. Benzo(a)pyrene, shellfish poison (paralytic shellfish and diarrhetic shellfish poisons), and radioactivity were not detected in the thawed oysters. These results suggest that frozen oysters can be safely used as a raw material for the preparation of seafood products.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.26-38
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• 2022

This study used the big data method to analyze the chronological frequency of seafood appearance and variety mentioned by the veritable records of the Joseon dynasty. The findings will be used as a basis for Joseon Period's food cultural research. The web-crawling method was used to digitally scrap from the veritable records of the Joseon dynasty of Joseon's first to the twenty-seventh king. A total of 9,536 cases indicated the appearance of seafood out of the 384,582 articles. Seafood were termed "seafood" as a collective noun 107 times (1.12%), 27 types of fish 8,372 times (87.79%), 3 types of mollusca (1.28%), 18 types of shellfish 213 times (2.23%), 6 types of crustacean 188 times (1.97%), 9 types of seaweed 534 times (5.60%). Fish appeared most frequently out of all the recorded seafood. Sea fish appeared more frequently than the freshwater fish. Kings that showed the most Strong Interest Inventory (SII) were: Sungjong from the 15^thcentury, Sehjo from the 15^th, Youngjo from the 18^th, Sehjong from the 15^th, and Jungjo from the 18^th respectively. Kings of Chosen were most interested in seafood in the 15^th and 18^th centuries.

• Journal of fish pathology
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• v.37 no.1
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• pp.147-153
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• 2024

The World Organization for Animal Health (WOAH) recommends two protocols (ITS and COI) for conventional PCR of G. salaris diagnosis. However, ITS PCR protocol may yield false-positive results, leading to unnecessary countermeasures. It's difficult to distinguish between G. salaris and false-positive by similar amplicon size of PCR, since the amplicon size of ITS PCR in G. salaris and false-positive was 1,300 and 1,187 bp, respectively. The nucleotide sequences of ITS false-positive in rainbow trout is 99.7% identical to previously reported host genome sequences of rainbow trout (Oncorhynchus mykiss) and 95.3 to 89.1% identical to those of other salmonid fish species. To reduce false-positive PCR band, PCR was performed by the different annealing temperature, but PCR bands were still detected. In RFLP analysis by HaeIII, the PCR product of G. salaris was digested into four bands of 512, 399, 234 and 154 bp, while the false-positive was digested into seven bands of 297, 263, 242, 144, 93, 80 and 68 bp. In the RFLP patterns digested by HindIII, G. salaris showed two bands of 659 and 640 bp, while false-positive had one fragment of 1,187 bp without any digestion. Therefore, the RFLP method of ITS PCR with HaeIII and HindIII can be used for differentiation between G. salaris and false-positive. These results might provide important information on the improvement of PCR diagnostic method of G. salaris.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.129-136
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• 2024

Lactic acid bacteria (LAB) growth in processed meat products produces slime. In this study, 10 different biofilm-forming LAB, including Leuconostoc mesenteroides, Lacticaseibacillus paracasei, Levilactobacillus brevis, Lactiplantibacillus plantarum, Leuconostoc citreum, Weissella viridescens, and Latilactobacillus sakei, were isolated from various meat products and identified based on 16S rRNA gene analysis. To inhibit biofilm formation by LABs, Eisenia bicycles methanolic extract (EB) and ethyl acetate soluble fraction (EA) were used as antibacterial and antibiofilm agents, respectively. Furthermore, EA and EB were employed to synthesize gold nanoparticles (AuNPs) such as EB-AuNPs and EA-AuNPs, which could serve as antibiofilm agents against the isolated LAB. These findings demonstrate that EA, EB-AuNPs, and EA-AuNPs exhibit significant antibacterial activity against the isolated LAB. Furthermore, EB-AuNPs reduced L. citreum biofilm production, whereas EA-AuNPs inhibited L. mesenteroides and L. brevis biofilm formation. The current results suggest that EB-AuNPs and EA-AuNPs can be used as nanomaterials to inhibit LAB that form biofilms on meat products.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.542-547
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• 2015

Since the oil price has been significantly jumped for several years, a heavy oil of low quality has been mainly used in the diesel engine of the merchant ship. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal were welded with GTAW method in the cast steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. Furthermore, the corrosion current density of the weld metal zone revealed the lowest value, having the highest value of hardness. The corrosive products with red color and local corrosion like as a pitting corrosion were considerably observed at the base metal zone, while these morphologies were not wholly observed in the weld metal zone. In particular, the polarization characteristics such as impedance, polarization curve and cyclic voltammogran associated with corrosion resistance property were well in good agreement with each other. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the Inconel 625 electrode.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.261-265
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• 1994

To detect naturally occurring bioactive compounds in unused marine resources such as marine by-products and algae, the screening test for the antimicrobial compounds containing in Asterina pectinifera, Halocynthia rotetzi skin, Nototodarus sloani ink. Anthocidaris crassispina skin, and four algae(Sargassum horneri, Agarum cribrosum, Odonthalia corymbifera and Desmarestia ligulata) was carried out. The minimum inhibitory concentrations(MIC, ${\mu}g/disk$) of ether and methanol fractions extracted from Sargassum horneri against Bacillus subtilis were 80 and 70 ${\mu}g/disk$, respectively. The MICs of the ether, acetone and methanol fractions extracted from Sargassum horneri against Staphylococcus aureus were 160, 180 and 70 ${\mu}g/disk$, respectively. In addition, the MICs of ether and acetone fractions extracted from Odonthalia corymbifera against Staphylococcus aureus were 50 and 170 ${\mu}g/disk$, respectively. These nonpolar fractions showed the strongest antimicrobial effect among several fractions extracted from tested marine resources.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1020-1025
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• 2004

In previous paper, contaminations of food-borne pathogenic bacteria of Saengshik was found to occur during processing, because detection rates of food-borne pathogenic bacteria in final products were higher than those of raw materials. In this study, methods to reduce food-borne pathogenic bacteria and improved manufacturing process were developed for microbial safety of Saengshik. Food-borne pathogenic bacteria in raw materials were reduced to about 0.5-2.0 log cfu/g when seven kinds of raw materials were washed with electrolyzed water and ozonated water, but food-borne pathogenic bacteria could not be removed completely. After improvement of manufacturing process, numbers of food-borne pathogenic bacteria were same or decreased to levels of raw materials. Gaseous ozone and Biocon could control air-borne bacteria under $1{\times}10^1$ cfu/1000 L of air in pulverization and mixing rooms.

• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.197-202
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• 2012

This study examined and compared the exopeptidase and endoprotease activities of the hepatopancreas (HP) of cuttlefish, squid, and octopus species. The protein concentration in crude extract (CE) from octopus HP was 3,940 mg/100 g, lower than those in CEs from squid HP (4,157 mg/100 g) and cuttlefish HP (5,940 mg/100 g). With azocasein of pH 6 as a substrate, the total activity in HP CE of octopus was 31,000 U, lower than the values for cuttlefish (57,000 U) and squid (69,000 U). Regardless of sample type, the total activities of the CEs with azocasein as the substrate were higher at pH 6 (31,000-69,000 U) than at pH 9 (19,000-34,000 U). With L-leucine-p-nitroanilide (LeuPNA) of pH 6 as the substrate, the total activity of the HP CE from octopus was 138,000 U, higher than values from both cuttlefish HP (72,000 U) and squid HP (63,000 U). Regardless of sample type, the total activities of the CEs with LeuPNA as the substrate were higher at pH 6 (63,000-138,000 U) than at pH 9 (41,000-122,000 U). With LeuPNA as the substrate, the total activities of the CEs from octopus HP and cuttlefish HP were higher at pH 6 than at pH 9. However, there was no difference in total activity between pH 6 and 9 for squid HP CE with LeuPNA as the substrate. These results suggest that the octopus HP is superior to the cuttlefish HP and squid HP as a potential resource for extracting exopeptidases. Exopeptidases from octopus HP have potential industrial applications and their use might aid in reducing pollution related to the octopus industry.

• Journal of fish pathology
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• v.37 no.1
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• pp.61-69
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• 2024

In this study, bacterial disease monitoring was conducted from July to November 2022 for three representative bacterial species (Streptococcus parauberis, Vibrio spp. and Edwardsiella piscicida) to investigate the occurrence of bacterial diseases in farmed olive flounder (Paralichthys olivaceus) on Jeju. Over a period of five months, 3,146 olive flounders were tested. The average length and weight of the olive flounder that were sampled for the disease were found to be 32.1 cm and 357.9 g, respectively. Bacteria were detected in 1,228 olive flounders, of which 24.6% were identified as Vibrio spp.. S. parauberis and E. piscicida were identified in 6.3% and 3.2% respectively, and 3% were unknown strains that could not be identified. Also, 41 (1.3%) olive flounders were found to have both S. parauberis and Vibrio spp. and 23 (0.7%) olive flounders were found to have both E. piscicida and Vibrio spp.. In particular, S. parauberis, Vibrio spp. (V. scophthalmi) and E. piscicida were detected simultaneously in one olive flounder. In fish infected with E. piscicida, the most obvious external signs were hernias and ascites.