• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.197-201
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• 2014

This study was performed to identify and assess food hazards during dry laver processing. Samples including raw materials, intermediates, and finished products during dried-laver processing were collected from seven dried-laver processing facilities, and microbial analyses were conducted. Microbial levels such as total coliforms and total viable cell count (TVC) increased as the processing steps progressed. TVC and total coliforms ranged from <30 to $9.1{\times}10^7$ CFU/g and <18 to 27,600 MPN/100 g for intermediates and finished products obtained during dried-laver processing, respectively. However, no fecal coliform was detected in the samples. Additionally, food-borne bacteria including Bacillus cereus, Listeria monocytogenes, Salmonella sp., Staphylococcus aureus, and Vibrio parahaemolyticus were not identified in finished products. For heavy metal content, arsenic ranged from 30.18 to 39.05 mg/kg, mercury from 0.005 to 0.009 mg/kg, and cadmium from 0.076 to 0.318 mg/kg dry mass in all finished products. However, lead was not detected in samples tested in this study. In conclusion, dried-laver products were safe based on the levels of food-borne bacteria and heavy metal contents. However, it is important to reduce total viable cell counts and total coliforms during dried-laver processing.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제50권4호
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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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• 제21권3호
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• pp.247-257
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• 2008

To understand the activity of non-specific defence factors in cultured Sebastes, the antibacterial effect of the serum, skin mucus and homogenate of various organs from cultured oblong rockfish (Sebastes oblongus) and rockfish(Sebastes schlegeli) against pathogenic bacteria, Aeromonas hydrophila, Edwardsiella tarda, Vibrio anguillarum, and Streptococcus sp. was compared with that of flounder(Paralichthys olivaceus) and seabass(Leteolabrax japonicus). And the activities of proteolytic enzyme, chitinolytic enzyme and haemolycin as non-specific defence factor were investigated on the oblong rockfish and rockfish. Samples from oblong rockfish showed the highest antibacterial activity by lysoplate assay on agar plate mixed with pathogens, followed in descending order by rockfish, seabass, and flounder. Turbidimetric assay was carried to evaluate the lysozyme activity of fish samples against lyophilized cells of Micrococcus lysodeiktikus. The serum, kidney, liver, stomach, intestine and eyeball of oblong rockfish and the mucus and gill of rockfish appeared to have the highest lysozyme activity among the fish strains investigated. All samples except skin mucus, liver, and eyeball of oblong rockfish and rockfish showed proteolytic enzyme activity. Chitinolytic enzyme activity was showed in random sampling and haemolytic activity was remarkable in oblong rockfish. Therefore, Sebastes strain was proved to have effective defense mechanisms based on the antibacterial activities, and lysozyme, proteolytic enzyme, chitinolytic enzyme, and haemolycin were considered to act as the non-specific defence factor of Sebastes.

• Korean Journal of Food Science and Technology
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• 제38권1호
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• pp.68-74
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• 2006

To utilize sea tangle single cell detritus (SCD) as food additive, SCD noodle was developed using mixture model. Flour improved, whereas water decreased texture of SCD noodles. Texture of SCD noodle decreased initially and then increased as SCD content increased. Flour and SCD increased, whereas water decreased $L^*$ and $b^*$ values of dried and cooked noodles. Flour decreased $a^*$ values of dried and cooked noodles, while SCD increased $a^*$ value of cooked noodle. Response constraint coefficient showed SCD influence on texture, and $L^*$ and $b^*$ values of dried and cooked noodles was higher than those of flour and water, whereas water influence on $a^*$ value was higher than those of flour and SCD. Texture and color values fitted nonlinear model with interaction terms for flour-water, flour-SCD, and water-SCD. Optimum mixing ratio value of flour : water : SCD was 63.3 : 31.0 : 3.7%. Sensory evaluation value of SCD noodles was lower than those of industrial and electrolyzed SCD noodles.

• Journal of fish pathology
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• 제4권2호
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• pp.87-94
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• 1991

In the late summer of 1990 and 1991, mass mortality occured among cage-cultured grouper, Epinephelus septemfasciatus in south cost of Korea. The moribund fish didn't feed and became pale or dark chestnut colour and irregularly swimmed due to the loss of equilibrium, finally the diseased fish fell down side away on the bottom or the surface of cage showing the bent of body and died. The diseased fish showed the extensive hemorrahge in brain, the swelling of spleen and bile duct as the specific syptoms of internal organs. So the gill, skin and other organs of the diseased fish were examined for the presence of pathogenic parasites and bacteria. The parasitic Trichodina sp. were detected only from the gill lamella of the diseased fish, but these parasites seemed to be not a direct causative agents that induced the gross mortality of the cultured grouper. because these parasites were also observed in normal grouper, yellowtail, red seabream and rock bream co-cultured with the diseased grouper in same or near cages. In the viral examination, although isolation of the causative agent by the use of estabilshed cell Lines, RTG-2 and CHSE-214, was not succeed, the normal grouper inoculated intramuscularly with the filtered homogenate of the organs of the diseased fish showed the same external and internal signs with the naturally infected grouper. They died within a week. By using the naturally and the artificially infected fishes, electron microscopic observation revealed numerous hexagonal or polygonal particles in the cytoplasm of liver cells. Based on the these results, we suggest that the mass mortality of the cultured grouper would be occurred by the infection of a viral agent.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제32권1호
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• pp.62-67
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• 1999

Infection rates of oyster ovarian parasite, Marteiliodes chungmuensis and productivity of the oyster shellstock infected with the parasite were investigated at the main seed collection areas in the southern coast of Korea where the extreme bad seed collection of oyster occurred in 1992 and 1993 to evaluate the cause of the bad seed collection. Additionally, the bacterial flora of the sea water and oyster lana were examined to identify the shellfish larva pathogenic bacteria like Vibrio sp. and Pseueomonas sp. In August 1992 to September 1993, infection rate of oyster ovarian parasite, M. chungmuensis at Tongyong, Kyongsangnam province, and Yosu, Chollanam province where the bad seed collection occurred, were $11.8\~100\%$ and $14.3\~100\%$, respectively. But the parasite was not detected in the shellstock collected at Daechon, Chungchongnam province. While a virus-like particle was identified in the cytoplasm of the egg infected by the parasite. The parasite infected egg was not able to fertilize completely. Uninfected egg in the gonad contaminated by the parasite could be able to fertilize but showed an abnormal development till D-shaped larva and then, died of necrosis after D-shaped lana. And some lana developed from low lipid content egg could not develop to the spat and died after the early umbo stage. The predominant bacteria in the oyster lana collected at bad seed collection areas were Pseudomonas sp. and Pseudomonas like bacteria and the occupancy rates were $53.3\~87.1\%$.

• Journal of the Korean Society of Food Science and Nutrition
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• 제38권10호
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• pp.1430-1437
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• 2009

Functional bread was manufactured with single cell detritus (SCD) of sea tangle. The optimum ingredient formula for SCD bread was determined based on mixture model. Flour and water reduced max weight, strength, hardness and specific loaf volume, whereas the increased SCD reversed the volume change of dough. Flour increased $L^*$ and $b^*$ values of SCD bread, while SCD decreased. Flour and water decreased $a^*$ value, while SCD increased. Max weight, strength, hardness, specific loaf volume, $b^*$ value and water holding capacity (WHC) were linear model on ANOVA table, whereas distance, volume change of dough, $L^*$ and $a^*$ values were nonlinear model. The response constraint coefficient showed that SCD influenced texture of SCD bread more than flour and water did, whereas water influenced the volume change of dough, specific loaf volume and WHC more than flour and SCD did. Moreover, flour influenced color value more than did water and SCD. Distance and $a^*$ value fitted nonlinear model with interaction terms for flour-SCD and water-SCD. Optimum ingredient formula for SCD bread was: flour, 48.25%; water, 30.89%; SCD, 3.86%. Sensory evaluation of SCD bread was a little lower than industrial bread and electrolyzed SCD bread.

• Journal of Life Science
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• 제25권11호
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• pp.1319-1323
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• 2015

Aquaculture continues to be an ever-growing sector. However, high-density farming increases disease outbreaks due to deteriorating water quality and internal stress. To prevent disease, the most common method chemotherapy is using antibiotic administration. In this study, probiotic bacteria were isolated from Korean traditional foods, such a Gochu pickle and cutlassfish salted seafood. Various bacteria were isolated, and their 16S rDNA sequences were analyzed. The antimicrobial activities of four isolates from Gochu pickle and seven isolates from cutlassfish salted seafood were assayed, in addition to the antibacterial activity of culture pellet and supernatant. The antibacterial activity of the pellet was higher than that of the supernatant. Isolate JKM-2 showed the highest antibacterial activity against Streptococcus iniae (43 mm), S. parauberis (40 mm), S. mutans (35 mm), and Vibrio vuinificus (26.5 mm). The sequences of the isolated strains were compared with those of Bacillus subtilis (97.71%), B. tequilensis (97.71%), Brevibacterium halotolerans (97.71%), B. subtilis (97.63%), B. subtilis (97.63%), B. mojavensis (97.54%), B. vallismortis (97.46%), B. nanillea (97.45%), B. methylotrophicus (97.37%), and B. ssiamensis (97.37%). Future through analysis and new strains confirmed the bacterial cell material investigation of JKM-3, and to ensure sufficient stability, it is desired to verify the utility value as a substitute material for antibiotics by application to the form of the industry.

• Korean Journal of Food Science and Technology
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• 제38권3호
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• pp.337-341
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• 2006

The quality characteristics of a surimi-based product with sea tangle single cell detritus (SCD) were studied in order to utilize SCD from sea tangle as a food additive. Mixture design and regression models were applied to optimize the processing conditions and to investigate the interaction between surimi and the other ingredients. Surimi and SCD decreased hardness and cohesiveness of surimi gels, and then increased them. Water increased hardness and then decreased it, whereas cohesiveness was reversed. Surimi and water increased gumminess and brittleness of surimi gels, but SCD decreased them. SCD increased water retention ability (WRA) and whiteness of surimi gels, whereas water decreased it. Hardness and cohesiveness fitted nonlinear models by ANOVA, but gumminess, brittleness, WRA and whiteness fitted linear models. The response constraint coefficient showed that surimi influenced hardness and whitenessmore than water and SCD, whereas water influenced WRA more than surimi and SCD. Moreover, SCD influenced cohesiveness, gumminess and brittleness more than surimi and water. Hardness and cohesiveness fitted nonlinear models with interaction terms for surimi-SCD and surimi-water, respectively. Optimum mixed ratio values of surimi, water, and SCD were 36.80, 57.07 and 4.14%, respectively, by mixture model.

• Korean Journal of Food Science and Technology
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• 제27권1호
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• pp.86-91
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• 1995

In order to expand the utility of alginic acid in the food industry, we have investigated to prepare low viscous alginic acid using a method for degradation of alginic acid with the enzyme system of Vibrio sp. AL-145. The enzyme showed maximum activity at pH 8.0 and $37^{\circ}C$, and was stable in the pH range 7.5 to 8.5 and at temperature up to $30^{\circ}C$, and 0.5M NaCl needed for the enzyme activity. The viscosity of alginic acid decreased with the reaction time courses regardless of alginic acid and enzyme concentration, and 90% of viscosity decreased with 60 min of reaction time, but the changes of reducing sugar not exhibited. The soluble concentration of partially degradated alginic acid(PDA) in water was about 10%(w/v), and adsorption capacity of $Ca^{2+}$ ion increased with increasing the concentration of PDA. The alcohol concentration on precipitation of PDA was higher than Na-alginic acid.