• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.319-327
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• 2022

An eight-week feeding trial was conducted to evaluate the effects of a diet consisting of different onion juice processing by-product (OJPB) levels on juvenile black rockfish Sebastes schlegelii growth, feed utilization, and, lysozyme and antioxidant enzymes activities. Juvenile rockfish (2.2 g) were randomly distributed into 15 flow-through tanks (30 fish/tank). Five experimental diets were prepared in triplicate. The experimental diets were supplemented with OJPB at different levels of 0 (control), 0.25, 0.5, 0.75 and 1% (designated as OJPB0, OJPB0.25, OJPB0.5, OJPB0.75 and OJPB1, respectively). At the end of the feeding trial, the results revealed that the fish that were fed the OJPB0.75 and OJPB1 diets showed enhancement in growth (weight gain and specific growth rate) and feed utilization (feed efficiency and protein efficiency ratio) compared with the fish that were fed other diets. Plasma lysozyme, glutathione concentration, and superoxide dismutase and catalase activities significantly increased in the fish that were fed the OJPB0.75 and OJPB1 diets. In conclusion, dietary supplementation of 0.75-1% OJPB in juvenile rockfish diet improved the growth performance and antioxidant status.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.4
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• pp.489-496
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• 2024

This study has investigated ten different organic acids in 67 types of seasoning Jeotgal (seasoning salted fermented product, SSFP) and Sikhae (seasoning salted fermented product with rice, SSFPR) collected from the market. The levels of organic acids varied significantly depending on the raw materials used for the SSFP and SSFPR. The acetic acid and lactic acid content ranged from being not detected (ND) to 5,667.15 mg/kg for acetic acid in the SSFP, ND to 34,837.89 mg/kg for lactic acid in the SSFP, and 53.47 to 2,089.55 mg/kg for acetic acid in the SSFPR, and 10.69 to 1,733.27 mg/kg for lactic acid in the SSFPR. The range for succinic acid was 57.92 to 2,793.09 mg/kg in the SSFP and 21.21 to 453.32 mg/kg in the SSFPR. Propionic acid content ranged from 8.42 to 277.83 mg/kg in the SSFP and 13.21 to 133.07 mg/kg in SSFPR.The most abundant organic acids were succinic and lactic acid, comprising 48% of the seasoning Jeotgal (succinic acid) and more than 72% in Sikhae (lactic acid). Furthermore, this study suggests that the differences in the organic acid content of samples, based on their raw materials can be discriminated by principal component analysis (PCA).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.1
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• pp.1-10
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• 2012

The objective of this study was to investigate the sanitary and nutritional requirements for the industrialization of commercial kwamegi from Pacific herring Clupea pallasii (CK-PH). The proximate composition of CK-PH was 46.4-47.2% moisture, 24.7-25.6% crude protein, 23.6-25.2% crude lipid, and 2.5-2.9% ash, which differed significantly from that of commercial kwamegi from the Pacific saury Cololabis saira. According to the volatile basic nitrogen content, heavy metal content, and viable cell and coliform group counts, products K and F (prepared by a general process) maintained their freshness, whereas product T (treated with green tea extract) did not. Products K and F contained five types of biogenic amine: agmatine sulfate (2,596 and 2,067 mg/kg, respectively), putrescine dihydrochloride (8.5 and 8.0 mg/kg, respectively), cadaverine (3.7 and 3.9 mg/kg, respectively), histamine (17.0 and 12.4 mg/kg, respectively), and spermidine (8.7 and 8.0 mg/kg, respectively). Product T contained six amine types: tyramine (12.5 mg/kg), agmatine sulfate (2,723 mg/kg), putrescine dihydrochloride (29.4 mg/kg), cadaverine (321.6 mg/kg), histamine (45.3 mg/kg), and spermidine (13.6 mg/kg). The total amino acid content of product K (22.16/100g) was 5.8% lower than that of product F. The major amino acids of products K and F were aspartic acid, glutamic acid, leucine, and lysine. No difference was found in the fatty acid composition of products K and F. The major fatty acids in products K and F were 18:1n-9, 20:5n-3, and 22:6n-3. Based on the recommended daily dietary allowances for Koreans, the significant minerals in products K and F were calcium, phosphorus, and magnesium.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.291-297
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• 1982

In this part of the studies on dielectric dehydration of foamed fish-starch paste, qualify stability and shelf-life of the product of which the preparation formula and processing conditions were described in previous report (Lee et al, 1982) were determined by means of accelerated reaction test. The product was stored for 50 days under the conditions of temperatures at 35, 45, and $55^{\circ}C$ in steady state and various water activities of 0.44, 0.52, 0.65, and 0.75, respectively. The loss of available lysine, extent of TBA value, and development of browning during the storage were measured and reaction kinetically analysed to assess quality stability and shelf-life of the product for the storage at room temperature of $25^{\circ}C$. Extent of browning was accelerated with the increase of water activity and temperature marking the time to reach a limit of color and flavor deterioration, or to reach brown color density of 0.17 O.D./g at 420 nm, 106 days at aw=0.44, $35^{\circ}C$, and 41 days at aw=0,65, $55^{\circ}C$, These reaction rates resulted in a prediction of shelf-life, 130 to 110 days in the storage at aw=0.44 to 0.75, $25^{\circ}C$. The quality limit assessed by TBA values and sensory evaluation of rancidity was 87 days at aw=0.44, $35^{\circ}C$, and 30 days at aw=0.75, $55^{\circ}C$ which gave a predicted shelf-life, 128 to 113 days . at aw=0.44 to 0.75, $25^{\circ}C$ storage.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.48-53
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• 2002

The HACCP (hazard analysis critical control point) concept becomes an important aspect of Good Manufacturing Practices (GMP) in safe food production. The HACCP plan was developed with food safety objective. The authors already carried out hazards analysis on Changran Jeotgal manufacturing process in a previous report. In this study we developed a HACCP plan on the manufacturing process of Changran Jeotgal. We could decide two CCPs those were salt concentration and eliminations of foreign materials before packaging. Foreign materials should be certainly checked out with laser detector just before packaging. Salt should be maintained more than $8\%$ to inhibit pathogenic bacteria in end product. On the Jeotgal process free water is removed after salting and Jeotgal is seasoned with several subsidiary materials such as com syrup. In result end products have $8\%$ salt with water activity 0.82. Most bacteria are inhibited but some can live in this condition. Materials on the working may be contaminate by pathogens, chemicals or physical hazards. It will be decreased by SSOP (standard sanitary operating program). The SSOP needed in Jeotgal plants is nearly same as other general food manufacturing plants but essential to fulfill HACCP program.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.43-47
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• 2002

Jeotgal, salt- fermented sea food, is a kind of Korean traditional foods. We carried out hazard analysis on Changran (stomach and intestine of Alaska pollack) Jeotgal and squid Jeotgal through the whole processing procedures at H Co. located at Guryongpo from April 2000 to September 2001. During this studying period, we educated employee regularly and analyzed hazards on the whole process and then could conclude that pathogenic bacteria and metal particles were most important hazards in Jeotgal. Metal particles in end-product will be eliminated by laser detector before packaging. But bacteria must thoroughly manage through the whole process. Bacteriological qualities of the end products were much improved after education for the employees and by effort for HACCP (Hazard Analysis and Critical Control Point) program introduction. Pathogenic bacteria such as pathogenic Escherichia coli, Salmonella spp., coagulase positive Staphylococcus aureus and Vibrio parahaemolyticus were not detected from not only raw materials but also end products. The falling bacteria in the places such as thawing area, packaging area, seasoning area, fermenting room, subsidiary materials room and storage room were less than 30 CFU per plate for 30 minutes during working time. But those were increased more than 10 times during the resting time. It means that special measures are needed during the break time such as lunch time or exchanging working teams.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.136-140
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• 2002

Every year fish skin, bone and intestines are discarded as processing waste material. The use of fish processing waste material is more economical and environmental-friendly. The leather-like material was produced using shark intestine. Physical charactistics such as tensile strength, elongation, tongue tearing strength, and bursting strength of the leather-like material were measured, and compared with those of a commercial leather product. The values of tensile strength, elongation, tongue tearing strength, and bursting strength of the leather-like material were $3.3kg/mm^2$, $53\%$, 13.0kg/mm and $18kg/cm^2$, respectively. Elongation $(l09\%)$ of the leather-like material coated with lacquer was higher than that of a commercial leather material, and the other factors were similar. The tensile strength and tongue tearing strength of the leather-like material was higher than those of shoes leather, but bursting strength was lower. These results suggested a potential value to use the leather-like material from shark intestines as a substitute for commercial leathers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.93-102
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• 1992

In order to reduce long preparating time for alkali pretreated B-type gelatin, enzyme pretreatment was tried on flounder(Limanda aspera) skin for I-type gelatin. The optimal extraction conditions of the B-type gelatin were 9 folds of added water with material(w/w), 3 hrs of extraction time, $60^{\circ}C$ of extraction temperature and pH 5. The maximum amount of I-type gelatin was extracted at $60^{\circ}C$ for 3 hrs using water controlled to pH 6.0(material : water= 1:9, w/w). The yields of the B- and E-type gelatin were $64.2\%\;and\;59.2\%,$ respectively. The B-type was superior to the B-type in physical properties such as jelly strength, viscosity and electric conductivity. Molecular weight of B-type was so far larger than that of the E-type due to different pretreatment method. Hydrolysis ratio of the E-type was higher than that of the B-type because of its molecular weight. Results suggest that B-type product would be better than I-type as fish skin gelatin but E-type was desirable in hydrolyzate preparation.

• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.13.1-13.8
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• 2018

Amyloid plaque, also called senile plaque, the product of aggregation of ${\beta}$-amyloid peptides ($A{\beta}$), is observed in brains of the patients with Alzheimer's disease (AD) and is one of the key factors in etiology of the disease. In this study, hydrolysates obtained from the sea hare (Aplysia kurodai) were investigated for ${\beta}$-secretase inhibitory peptide. The sea hare's muscle protein was hydrolyzed using six enzymes in a batch reactor. Trypsin hydrolysate had highest ${\beta}$-secretase inhibitory activity compared to the other hydrolysates. ${\beta}$-secretase inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. ${\beta}$-secretase inhibitory peptide was identified as eight amino acid residues of Val-Ala-Ala-Leu-Met-Leu-Phe-Asn by N-terminal amino acid sequence analysis. $IC_{50}$ value of purified ${\beta}$-secretase inhibitory peptide was $74.25{\mu}M$, and Lineweaver-Burk plots suggested that the peptide purified from sea hare muscle protein acts as a competitive inhibitor against ${\beta}$-secretase. Results of this study suggest that peptides derived from sea hare muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.317-322
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• 1998

Generally, the conventional fish size grading methods just adopt the mechanical technique. So the grading methods have a problem such that the graded fish is easy to hurt on the skin and in the internal organs. In this paper, a fish size grading machine is developed using an image processing method. The grading method is based on the principal axis theorem. The length and projected area of a fish are obtained by getting the principal axis and the product of inertia moment on the captured image of a target fish. The developed machine uses an uncontact technique that the target fishes go through the front side of the CCD camera. So the above stated problem can be improved. The performance of this method is discussed with the experimental results.