• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.161-168
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• 1988

The Stability of PSP extracted from the intoxicated sea mussel, Mytilus edulis was evaluated by the thange of heating conditions and pH of the PSP solution. Also the composition of the PSP extracted from the cultured sea mussel collected at Chungmu, Korea on March 12, 1986 was analyzed. The extracted PSP was stable over the range of pH 2.0 to 4.0, but it was unstable above pH 4.5. For example. the toxicity of extracted PSP of pH 3.0 was only decreased less than $20\%$ by the treatment at $121^{\circ}C$ for 15min or at 100 for 2 hours, but it was decreased more than $80\%$ by the same treatment when the pH of the PSP solution was adjusted to 6.0. The toxin was purified from the ethanolic extract of the digestive glands of the sampled sea mussel by Bio-gel P-2 and Bio-Rex 70 column chromatography. The toxic fractions obtained were analyzed by cellulose acetate membrane electrophoresis, TLC and HPLC. The compositional analytical results of the PSP, most of the toxins were certified as $GTX_{1-4}$, while the toxicity of STX was only about 1/40 of that of $GTX_s$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.37-45
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• 1975

The present study was ,conducted to evaluate the effects of condensed phosphates on the refeezing damage of Alaska pollack muscle. The fillets were dipped in such solution as 5 and $10\%$ sodium polyphosphate, 1 and $5\%$ mixture of sodium polyphosphate and sodium pyrophosphate (1:1, w/w) for 1 and 5 minutes, respectively, before refreezing. And fillets were frozen at $27^{\circ}C\~28^{\circ}C$ and stored for 15 days at $-18^{\circ}\~-20^{\circ}$. The degree of denaturation was estimated by determining amounts of drip relased, content of total solids, nitrogen, and DNA in the drip an cooking-weight-loss. Phosphorus absorbed in the muscle was also determined. Phosphorus absorbed in the fillets treated with loft solution of sodium polyphosphate for 5 minutes amounted to 101 mg/100g muscle as $P_2O_5$. The absorption was dependent on tile concentration of treating solution rather than on the dipping time. The increase of phosphorus absorption seemed to affect to reduction of drip. Among the treating conditions, $10\%$, 5 minutes and $10\%$ 1 minute with sodium polyphosphate appeared most effective ones on drip reduction. The effect of $5\%$, minutes with the mixture of sodium polyphosphate and sodium pyrophosphate did not show so benefitable effect in refrozen fillets. As a tendency total solids, nitrogen, and DNA in tile drip varied proportionally to the amount of drip released. And the content of DNA was lower than the amount. Treatment, at higher the concentration and longer the dipping time, resulted in the lower cooking-weight-loss and the better quality on organoleptic test of thawed fillets.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.419-430
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• 1987

The damage of plasmid DNA by lipid peroxidation and its inhibition were investigated through the model system of DNA and linoleic acid at $37^{\circ}C$. The degree of DNA damage increased in proportion to the increase of concentration and peroxidation of linoleic acid. DNA damage induced from linoleic acid peroxidation was greatly inhibited by the addition of active oxygen scavengers, especially, singlet of oxygen scavenge$(\alpha-tocopherol,\;cysteine)$ and superoxide anion scavenger(superoxide dismutase, ascorbic acid) in reaction system. These active oxygens, such as superoxide anion and hydrogen peroxide were rapidly generated in the early stage of peroxidation (POV below 100 mg/kg) and also scanvenged by the addition of superoxide dismutase and catalase, respectively. Hydroperoxide isolated from autoxidised linoleic acid showed DNA damage. Hydroperoxide induced-DNA damage was not inhibited by active oxygen scavengers. Lipid oxidation products, malonaldehyde and hexanal, also influenced on the DNA damage. Accordingly, it is speculated that DNA damage by lipid oxidation products is due to active oxygens such as singlet oxygen and superoxide anion formed in the early stage of peroxidation, direct action of hydroperoxide and formation of low molecular carbonyl compound-DNA complex. Furthermore, DNA damage induced by lipid peroxidation was remarkably inhibited by the addition of active oxygen scavengers and natural antioxidative fractions extracted from garlic and ginger. These antioxidative fractions also suppressed the generation of active orygens and linoleic acid oxidation. It is assumed that the inhibition of DNA damage by garlic and ginger extracts is due to the scavenging effect of active oxygens and the inhibition of hydroperoxide and oxidation products formation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.463-468
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• 1987

The present paper was investigated to elucidate the nitrite-scavenging ability of vegetable extracts. Vegetable extracts possessed the scavenging ability of nitrite. By fractionatioh of vegetable extracts,nitrite-scavenging ability of garlic (Allitum sativum for. Pekinense), chinese pepper (Zanthexylum schinifolium), onion (Allium cepa), welsh onion (Allium fistulosum) and ginger (Zingiber officinale) extracts were effective in the water-soluble fraction, but carrot (Daucus carota uar. sativa) in the methanol-soluble fraction. Nitrite-scavenging ability of vegetable extracts was also pH-dependent, highest at pH 1.2 and lowest at pH 6.0. Particularly, nitrite-scavenging abilities of water-soluble fractions obtained from garlic and chinese pepper were similar to that of L-ascorbic acid at pH 1.2. After vegetable extracts were treated with sodium borohydride, nitrite-scavenging ability was remarkably decreased at pH 1.2. It is assumed that reducing powers of vegetable extracts participated in their nitritescavenging abilities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.469-475
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• 1987

The present paper was investigated to elucidate the nitrite-scavenging ability of seaweed extracts. Seaweed extracts possessed the scavenging ability of nitrite. By fractionation of seaweed extracts, nitrite-scavenging ability of laver(Porphyra tenera), sea lettuce(Enteromorpha compresa) extracts were effective in the water-soluble fraction, but sea mustard (Undaria pinnatifida), sea staghorn (Codium fragile) extracts in the methanol-soluble fraction. Nitrite scavenging ability of seaweed extracts was also pH-dependent, highest at pH1.2 and lowest at pH6.0. Particularly, nitrite-scavenging abilities of water-soluble fractions obtained from laver and sea lettuce were similar to that of L-ascorbic acid at pHl.2. After seaweed extracts were treated with sodium borohydride, nitrite-scavenging ability was remarkably decreased at pH1.2. It is assumed that reducing powers of seaweed extracts participated in their nitrite-scavenging abilities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.213-218
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• 1987

The DNA damage mechanism by fish oil peroxidation was investigated through the model system of a DNA-mackerel lipid at $37^{\circ}C$. Mackerel lipid peroxidation products induced a great DNA damage with the increment of its concentration, and such DNA damage in all systems examined occurred below $100millieq{\cdot}/kg$ in POV (peroxide value) Singlet oxygen $(^1O_2)$ and superoxide anion${\cdot}O_2^-$ greatly participated in the DNA damage during peroxidation of mackerel lipid, while hydrogen peroxide$(H_2O_2)$ and hydroxyl radical $({\cdot}OH)$ did little show the DNA damage. From the results of the addition of several active oxygen scavengers to the DNA-lipid systems, singlet oxygen ana superoxide anion greatly affected to the increase of POV ana to the DNA damage by mackerel lipid peroxidation, respectively. It indicates that there was a close relationship between the effects of active oxygens in the mackerel lipid peroxidation and its DNA damage mechanism.

• Tunnel and Underground Space
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• v.22 no.5
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• pp.321-329
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• 2012

Laboratory tests for measuring absorption, porosity, P-wave velocity and uniaxial compressive strength (UCS) were performed to examine weathering characteristics of ilmenite by microorganism. Physical property changes were quantitatively estimated with comparing culture period on the condition of abiotic oxidation without microorganism and biooxidation with microorganism. As a result, the measured pH during 45 days was distributed in the range from 3.82 to 4.26, on the other hand, biooxidation showed the range from 2.20 to 2.57. The measured absorption according to microorganism and culture period represented 0.052% at final stage in the case of abiotic oxidation and 0.073% in the case of biooxidation. Porosity showed 0.206% at final stage in the case of abiotic oxidation and 0.281% in the case of biooxidation. In general, the values by biooxidation showed higher than that by abiotic oxidation. Change range of P-wave velocity with culture period showed that the measured value as 1410 m/s at final stage in the case of biooxidation was lower than 1886 m/s of that in the case of abiotic oxidation. The UCS was decreased with increasing culture period in all specimens and represented 241.1 MPa at final stage in the case of abiotic oxidation and 140.0 MPa in the case of bioxidation. In conclusion, it implies that influence of physical property on ilmenite by biooxidation related with microorganism was larger than that by abiotic oxidation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.191-198
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• 1982

Histamine has been known to be one of the causative materials of allergy-like food poisoning from the dark-fleshed fishes. In the early stage of spoilage, the dark-fleshed fishes have been known to be accumulated the level of 100mg/100g associated with outbreak of allergy-like poisoning. The present paper was conducted to elucidate the changes of histamine content in the canned boiled dark-fleshed fishes, such as common mackerel, Scomber japonicus, and sardine, Sardinops melanosticta, under different condition of processing and storage. Additionally, histamine content was determined in the canned boiled common mackerel, sardine and mackerel pike purchased from the supermarket. The results summarized are as follows : Changes of histamine content during storage of the canned fishes were nearly not found. The both factors of the storage time and temperature were not to the histamine content. Histamine was detected in concentrations of 7.24 to 14mg/100g in the canned sardine, 11.38 to 28. 8mg/100g in the common mackerel, and 13.88 to 21mg/100g in the canned mackerel pike purchased from the supermarket. The amount of histamine in the canned dark-fleshed fishes is less than that of inducing allergy-like food poisoning, and from the viewpoint of food hygiene these canned fishes are assessed to be safe.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.551-556
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• 1992

To develop natural antioxidant from spices and control thermal oxidation of edible soybean oil, the available antioxidative compounds of various spices were extracted with edible soybean oil. The storage stability of the oil mixed with purified sardine oil and soybean oil containing that extracts at $37^{\circ}C$ were investigated. Furthermore the antioxidative activity of petroleum ether soluble fractions(PESF) obtained from rosemary on the thermal oxidation of edible soybean oil during heating at $180^{\circ}C$ were also investigated. By mixing with refined sardine oil and soybean oil extracts of rosemary, sage of herb spices and mace of seed spices, the oxidative stabilities were remarkably increased. The thermal oxidation of edible soybean oil was also supressed by the addition of 1.0%(w/w) of PESF obtained from rosemary. Rosemary extract exhibited higher antioxidative activity on thermal oxidation of edible soybean oil than butylated hydroxytoluene.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.875-881
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• 1998

To develop functional food material with angiotensin converting enzyme (ACE) inhibitory peptides, muscle protein of anchovy, Engraulis japonica was hydrolyzed during 48 hrs by digestive pretenses such as pepsin, trypsin, $\alpha$-chymotrypsin, and commercial proteases such as papain, bromelain, complex enzyme, Elavourzyme, Novozym, Neutrase, Protamex and Alcalase. The only $50\%$ ethanol soluble hydrolysates were tested for inhibitory activity against ACE and yield of $50\%$ ethanol soluble peptide-nitrogen ($ESPN_{50}$). ACE inhibition effects and yield of $ESPN_{50}$ occurred as hydrolysis time increased to 8 hrs, Among those pretenses tested, hydrolysates by Alcalase and $\alpha$-chymohypsin had greater ACE inhibitory activity (80 and $74\%$, reipectively) with eletated levels of $ESPN_{50}$ (48 and 58 mg/ml, respectively), while Protamex hydrolysates had greater ACE inhibitory activities ($73\%$) with reduced levels of $ESPN_{50}$ (7.2mg/ml) than others. Amino acid compositions of $50\%$ ethanol solubles obtained from those hydrolysates were rich in glutamic acid, aspartic acid, cysteine and leucine.