• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.352-358
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• 2017

The object of this study is to assess physicochemical and microbiological hazards involved during the processing of shellfish products such as oysters, clam, and mussels. Samples including raw materials, intermediates, and final products in the processing process were collected from seven simple-processed shellfish facilities. In the samples obtained from the facilities, viable cell count and coliform group were detected less than that of the Korean Government guidelines. In addition, the high-risk bacterial pathogens such as Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes were not identified in raw materials and final products. However, the low-risk pathogens, Staphylococcus aureus and Vibrio parahaemolyticus, were detected in some final products. The level of heavy metal content in the final products tested in this study meets the recommendations by the Korean Government standard guidelines. No foreign materials in the final products were also observed. Considering these results, it was concluded that no significant food hazards exists in the processing process of simple-processed shellfish products. However, it is essential to improve the food safety control in the shellfish processing facilities since S. aureus, a personal sanitary indicative bacterium, was continuously detected over seven simple-processed shellfish facilities.

• Journal of fish pathology
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• v.34 no.1
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• pp.117-121
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• 2021

An ayu (Plecoglossus altivelis) farm in Korea recently experienced an epidemic of vertebral column deformities where about 90% of fry displayed a vertebral column that was grossly opaque along either the cranial part of the column or its entire length. Abnormal fish were lordotic, scoliotic and/or kyphotic about midway down the spine. Examination of serial sections of whole fish showed only histological lesions in the vertebral column and suggested some disturbance in the early development of the vertebral centrum. Such abnormalities included a frayed spinal or notochord sheaths with irregular thickening and compression, mal-absorbed notochord cells, thickening of around cell layer and hypercellularity on both facets of the notochord sheath. No parasites, fungi, or bacteria were detected. While this lesion has only been reported once in the past, this is the first report of histopathological findings.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.451-462
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• 2016

The molecular weight of proteins and protein hydrolysis products (PHP) in the fractionated post-production marinating brines left after herring marination process was determined by the HPLC. The proteins and PHP retention was evaluated in the three-stage purification process with the usage of polypropylene bag ($25{\mu}m$) and ceramic membranes with the cut-off of 150 and 1 kDa. It was found that the process of marination contributes to high participation of compounds in the post-production marinating brines. Those are characterised by low molecular weight, formed as a result of protein hydrolysis. Each stage of the scavenging process was reducing the content of proteins and PHP. The lowest retention was observed in the stage at which a PP bag was used, while the highest in the UF process, with the usage of 150 kDa membrane. The total retention of proteins and PHP differed according to the type of post-production marinating brines and reached the level of 16-22%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.425-430
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• 2022

This study was designed to verify the shelf-life of a freeze dried-block type of convenience food for rockfish Sebastes schlegeli seaweed soup product stored at different storing temperatures (25, 35, and 45℃) for 5 months. The polyunsaturated:saturated fatty acid ratio of the product stored at 25℃ was higher than that of products stored at 35℃ and 45℃ for 5 months. The colorimetric assessment indicated a noticeable decrease in the brightness of product color after 5months of storage at 35℃ and 45℃. Increased storage temperature and time negatively affected the product color. The products stored at 35℃ and/or 45℃ for more than 3 months tended to be more yellowish-red in color than those stored at 25℃ for shorter periods. No disease-causing microorganisms, including Escherichia coli and Staphylococcus aureus, posing health hazards to the human, were detected on food safety evaluation, regardless of storage conditions. Based on food visual shelf life simulator the shelf life of the rockfish seaweed soup was estimated approximately 22 months, considering the data from yellowness the safety factor of 0.7.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.169-173
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• 2010

This study evaluated the effects of gamma ray irradiation on the safety of dried seafood products. Dried salted squid, Engraulis japonica, Hizikia fusiformis, Mytilus coruscus, and Porphyra tenera were gamma-irradiated at doses of 0, 1, 3, and 5 kGy. The total bacterial populations were then enumerated on total plate count agar, and bacteria isolated from the samples were identified by 16S rDNA sequencing. In addition, the isolated strains were inoculated in the products to determine $D_{10}$ values. The total bacterial populations in the dried seafood products ranged from 3.40 to 6.59 log CFU/g, and those of yeasts and molds ranged from 2.21 to 4.56 log CFU/g. The sequence analysis identified Staphylococcus sp. as the most common species in the dried seafood products, except for dried P. tenera. The $D_{10}$ values of the contaminating bacteria were lower than 0.7 kGy, except for Deinococcus sp., which had a value of 1.39 kGy. This study demonstrated that gamma irradiation could be used to improve the safety of dried seafood products.

• Korea Trade Review
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• v.44 no.2
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• pp.109-126
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• 2019

Import refusals can be considered a new method of non-tariff barriers. This study aims to analyze reputation spillover effects on fish and fishery products imported from ASEAN countries to the U.S. FDA. The supply of aquatic products is not stable due to various factors such as reduction of fish stocks and climate change. Fish is a basic food ingested directly, but there are many ways to control the safety of aquatic products. ASEAN countries account for about 20% of U.S.imports in fish and fishery products. For Southeast Asian countries, fish and fishery products comprise a high proportion of exports revenue. Despite the large share of exports to the U.S., Southeast Asia countries have been receiving many import refusals from the United States. In this study, a theoretical model for examining import refusals is suggested using the negative binomial counting process. The reputation spillover effect, was divided into two spillover effects of 'neighbor reputation' and 'sector reputation'. Results show that there exists a neighbor reputation spillover effect. It can be said if there was a import refusal of the same product from neighboring countries in the preceding year, the home country have a possibility to experience import refusals of the same product. Therefore, it is interpreted that neighboring countries have good standard compliance can help home countries to effectively reach the target markets. Our findings have a important policy implication for ASEAN exporters of fish and fishery products.

• Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.70-74
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• 2006

DNA sequence-based typing is considered a robust tool for the discrimination of dinoflagellate species because of the availability of extensive rDNA sequences. Here, we present a rapid, cost-effective DNA-sequencing technique for various PCR products. This sequencing strategy relies on 'nested' or 'tailed' primer labeled with near-infrared dye, and uses a minimal volume of unpurified PCR product (ca. $5{\mu}L$) as the DNA template for sequencing reactions. Reliable and accurate base identification was obtained for several hundred PCR fragments of rRNA genes. This quick, inexpensive technique is widely applicable to sequence-based typing in clinical applications, as well as to large-scale DNA sequencing of the same genomic regions from related species for studies of molecular evolution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.77-84
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• 2004

The powder and liquid products of seasoned and smoked skipjack tuna (Euthynus pelamis) was manufactured by using small skipjack tuna (1-2 kg, 20-30 cm) captured in the East Sea, Korea. Smoking was done three times at $80^{\circ}C$ for 8 hrs to decrease the moisture content below $15\%.$ The seasoned and smoked skipjack tuna powder with liquid smoke showed the lower pH than the control. The pH, VBN, amino nitrogen content, and TBA value were increased slowly as storage period was increased at room temperature. Liquid smoke decreased the production of animo nitrogen and VBN. Vacuum packaging was efficient for inhibiting the deterioration and the microbial growth of the seasoned and smoked skipjack tuna powder product.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.79-85
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• 2009

Gelatin hydrolysates with a high inhibitory activity against angiotensin I-converting enzyme (ACE) were fractionated from Alaska pollock surimi refiner discharge. The ACE-inhibitory activity, expressed as $IC_{50}$ (mg/mL), was highest (0.49 mg/mL) in gelatin hydrolysates formed by sequential 2-hr treatments of Pronase and Flavourzyme. After fractionation through four different membrane filters with molecular weight cut-offs of 3, 5, 10, and 30 kDa, the highest ACE-inhibitory activity (0.21 mg/mL) was observed with the 3-kDa filtrate.

• Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.10.1-10.14
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• 2019

Fish skin waste accounts for part of the solid waste generated from seafood processing. Utilization of fish skin by bioconversion into high-grade products would potentially reduce pollution and economic cost associated with treating fish processing waste. Fish skin is an abundant supply of gelatin and collagen which can be hydrolyzed to produce bioactive peptides of 2-20 amino acid sequences. Bioactivity of peptides purified from fish skin includes a range of activities such as antihypertensive, anti-oxidative, antimicrobial, neuroprotection, antihyperglycemic, and anti-aging. Fish skin acts as a physical barrier and chemical barrier through antimicrobial peptide innate immune action and other functional peptides. Small peptides have been demonstrated to possess biological activities which are based on their amino acid composition and sequence. Fish skin-derived peptides contain a high content of hydrophobic amino acids which contribute to the antioxidant and angiotensin-converting enzyme inhibitory activity. The peptide-specific composition and sequence discussed in this review can be potentially utilized in the development of pharmaceutical and nutraceutical products.