• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.458-465
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• 1999

Distribution of the proteolytic activities of crude pretense extracted from the viscera of ten kinds of fish was examined. Their proteolytic activities on proteinous substrates (azocasein, hemoglobin, and casein) from the viscera of anchovy, bastard flatfish, mackerel and red sea bream were higher than those of other fishes, and the crude pretenses were further fractoinated with acetone or ammonium sulfate. Optimum concentrations for pretenses fractionation were $0\~55\%$ for acetone and $30\~70\%$ for ammonium sulfate. The fractionated viscera pretense of mackerel showed the highest proteolytic activity among four kinds of fishes. Activities of cathepsin D- and pepsin-like enzymes at pH 3.0, cathepsin L-, B-, H- and G-like enzyme at pH 6,0, and Hypsin- and chymotrypsin- like enzymes (pH 8.0) were detected in the fractionated viscera pretense, whereas activities of cathepsin L- and chymoeypsin-like enzyme were observed in commercial pretenses. Proteolytic activities of Alcalase, Protamex, and Aroase AP-10 for azocasein were slightly higher than the fractionated viscera pretenses, but their amidolytic activities at pH 6.0 and 8.0 toward synthetic substrates were lower than counterpart. The fractionated pretenses from fish viscera would be utilized as commercial pretenses.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.56-61
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• 2019

In this country, mackerel landing, sorting, and packing are mostly performed manually, which is time consuming and labor intensive. An unloading automation system saves time and labor by automating the landing, sorting, and packing processes. Casers are devices for manufacturing packing boxes for fish used by unloading automation systems. The caser design in this study is for mackerel packing boxes. This caser makes a packing box based on a press using the caser's slide crank. When the caser makes a packing box, the manufacturing sequence is determined by the caser's production guide and assisting rod. The caser design in this study is simulated using a multi-body dynamics program. The simulation is used to analyze the caser and to visualize the box-making sequence.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.458-464
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• 1993

In the present paper enzymatic properties of the trypsins from the four dark fleshed fish were compared with each other and thermal stabilities of the enzymes were also investigated. The trypsins from the dark fleshed fish showed their activity only in BA-p-NA substrate of the amide substrates such as BA-p-NA and SP-p-NA, and BAEE and TAME of the ester substrate such as ATEE, BAEE, BTEE, and TAME. The enzymes were strongly inhibited by the serine protease inhibitors such as antipain, leupeptin, TLCK, DFP and SBTI, and were also inhibited by such metal ions as Cu$^{2＋}$ and Hg$^{2＋}$, but fairly activated by $Mg^{2＋}$. Denaturation constants of the enzymes were 13.4$\times$10$^{-4}$ sec$^{-1}$ for anchovy trypsin, 47.18$\times$10$^{-4}$ sec$^{-1}$ for mackerel trypsin A, 34.06$\times$10$^{-4}$ sec$^{-1}$ mackerel trypsin B, 42.28$\times$10$^{-4}$ sec$^{-1}$ for yellowfin tuna trypsin and 16.6$\times$10$^{-4}$ sec$^{-1}$ for albacore trypsin at 55$^{\circ}C$. The activation energies of the trypsins at a temperature range of 3$0^{\circ}C$ to 5$0^{\circ}C$ were estimated to be 13.91 ㎉/mole for anchovy trypsin, 11.61㎉/mo1e and 8.43㎉/mole for mackerel trypsin A and for mackerel typsin B, 4.35㎉/mole for yellowfin tuna trypsin, and 3.76㎉/mole for albacore trypsin.

• Journal of the Korean Professional Engineers Association
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• v.32 no.4
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• pp.104-118
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• 1999

Alaska Pollack (Theragramma), Mackerel (Socomber japonicus), yellow corvenia (Pseudosc iance manchurica) were dressed, and then meat was separated from the other parts through a fish meat separator. After dehydration, the meat was ground with a silent cutter, packaged in polyethylene bags, and stored at -15。C for days. Samples were taken at regular intervals throughout the storage period and investigated for changes in puality characteristics such as the amounts of nitrogenous compounds, degree of lipid oxidation, fatty acid composition, and organoleptic factors. The resrlts obtained in this study were as follows; 1. The volatile basic nitrogen[VBN] contents of Alaska pollack, and yellow corvenia meat pastes increased from 14.4, 11.2 and 10.8mg% to 41.6, 38.3 and 40.6mg%, respectively during a 120 day storage period, whereas the trimethylamine oxide nitrogen [TMAO-N] contents decreased from 117.2, 12.8 and 17.2mg% to 40.3, 2.6 and 7.1mg% during the same period. 2. The TBA value of the mackerel meat paste showed a maximum peak after 60 days, and then decreased gradually, whereas the TBAvalues of the alaska pollack and yellow corvenia meat pastes increased steadily during the same period. The acid values of the meat pastes increased during the storage period, while the iodine values decreased. 3. The fatty acid composition of the total lipid of the meat pastes changed considerably during ghe 120 days storage period : saturated fatty acids in the total lipid such as myristic, palmitic, and stearic acid increased, while unsaturated fatty acids such as linoleic, gadoleic, eicosapentaenoic, erucic and docosahexaenoic acid decreased steadily. The initial percentage contents of the unsaturated fatty acids in the total lipid of the Alaska pollack, mackerel, and yellow corvenia meat pastes were 87.2%, 63.9%, and 75.9% respectively. However, the contents decreased to 46.0%, 42.5% and 51.3% after the 120day storage period. 4. The color of the meat pastes changde gradually into dark brown. L values of the meat paste measured with a thistimulus colorimeter decreased steadily during the storage period, while a and b values increased during same period. 5. Judging from the results of organoleptic evaluation on the fish odor, color and overall acceptability, significant difference were found between the odor and color of the mackerel and those of the yellow corvenia meat pastes. Overall acceptability score of yellow corvenia was higher than that of Alaska pollack or mackerel meat pastes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.731-736
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• 2016

No freshness indicator for fish has yet been established. Thus, we investigated changes over time in mackerel quality in an effort to development useful indicators. Fresh whole mackerel Scomber japonicus were stored at $4^{\circ}C$ immediately after capture and quality changes were evaluated every 3 days for a total of 15 days. Whole fish were divided into ventral parts (VPs) and dorsal parts (DPs); we measured the trimethylamine (TMA) and volatile basic nitrogen (VBN) levels, pH values, and color values in/of these parts. The TMA and VBN levels tended to increase during storage and the TMA changes in VPs were higher than those in DPs. In particular, the VP TMA content attained a maximum of 3.68 mg/100 g at 6 days, and the VBN content attained a maximum of 20.88 mg/100 g at 9 days, suggestive of initial fish spoilage. The pH ranged from 5.99-6.17 over the first 3 days and from 6.17-6.38 from days 6-15. Surface color changes on VPs and DPs were explored. Significant decreases in both VP lightness and yellowness were evident after 3 days. The data suggest that both TMA level and lightness of the color are valuable indicators of freshness in the initial stage of mackerel retail.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.589-597
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• 2010

Monthly changes in the proximate and fatty acid compositions of chub mackerel (Scomber japonicus) muscle during cultivation from October 2007 to September 2008 were investigated. The lipid content increased gradually from the first stage of cultivation until March 2008 and then dramatically until May, before decreasing. The highest lipid content during cultivation was 21.6% in May, just before the fish spawns. There was a negative correlation (y=-1.1585x+87.741, $R^2$=0.9495) between the lipid and moisture contents during cultivation of chub mackerel. By contrast, the protein ($18.6{\pm}1.05%$) and ash ($1.18{\pm}0.11%$) contents were essentially unchanged during cultivation. Prominent fatty acids in chub mackerel muscle were 16:0, 18:0, 14:0 saturates, 18:1n-9, 16:1n-7, 18:1n-7 monoenes, and 22:6n-3 (docosahexaenoic acid, DHA), 20:5n-3 (eicosapentaenoic acid, EPA), and 18:2n-6 polyenes. The percentages of n-3 polyunsaturated fatty acids (PUFA), such as DHA and EPA, were higher during three months in the early stage of cultivation than they were subsequently. However, the PUFA (DHA+EPA) content (in mg/100 g of muscle) was lower in the early stage (740-796 mg/100 g muscle) than in the other stages. The highest PUFA (DHA+EPA) content was from April to May (2,749-2751 mg/100 g muscle). The PUFA content was positively correlated with the total lipid content of chub mackerel muscle during cultivation. The results indicate that cultured chub mackerel is a very good source of n-3 PUFA, such as DHA and EPA.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.465-474
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• 2014

This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an $IC_{50}$ value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ${\geq}2.5 $ MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HD-Cinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.

• Journal of Aquaculture
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• v.6 no.3
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• pp.213-219
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• 1993

Two studies were carried out: to compare commercial flounder diets (C1-C6) with a laboratory-formulated diet (S), and to evaluate moist pellet (MP) prepared with or without raw fish for olive flounder culture. In experiment I, three replicates of 20 fish (42 g in average) each were fed S or each of C1-C6 for four weeks at $17^{\circ}C. For experiment 2, three replicates of 400 fish (78 g in average) each were fed $100\%$ laboratory-formulated grower diet (G), 50\%\;G+50\;%$ frozen mackerel containing $70\%$ moisture or $50\%\;C6$ (the same diet as that used in Exp. 1) +$50\%$ frozen mackerel for six weeks. Weight gain of fish fed S was significantly (P< 0.05) higher than that of fish fed C2 or C3 (26.7 vs 15.4 or 17.5g/fish over the 4-week period, respectively). Feed efficiency was significantly (p<; 0.05) lower in fish fed C2 than in fish fed S but was not different (P> 0.05) between the fish fed Sand the other commercial diets. No significant differences in weight gain were found among the fish fed $100\%\;G,\;50\%\;G+50\%$ frozen mackerel or $50\%$ C6+frozen mackerel. The results of our studies indicate that most of the commercial flounder diets can be improved for better growth, when we compared these diets with a laboratory-formulated diet, and the growth of flounder fed MP containing no raw fish was as good as that of those fed MP prepared with raw fish.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1030-1035
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• 2002

Despite health benefits derived from fish oil, polyunsaturated fatty acids (PUFAs) contained in fish oil are susceptible to lipid oxidation. To determine the optimum condition for maintaining good quality cooked fish during storage, mackerels were broiled with salt or soysauce condiments, and the lipid oxidation during 12 days of storage at refrigerated condition was measured. Peroxide value of broiled mackerel group with salt significantly increased after immediate cooking and maintained higher value throughout the storage period compare to the soysauce-added group, but showed similar value to the control group. Conjugated diene content in the soysauce-group was lower than the control and salt-added groups. Malondialdehyde content of broiled mackerel increased twofold and showed similar values in soysauce-added and the control groups during storage, whereas increased in the salt-added group significantly. Fatty acid compositions of the three mackerel groups changed after cooking, whereas that of the control group was almost stable during storage. In comparison with raw mackerel, the ratio of PUFA and saturated fatty acids decreased significantly, and the content of n-3 family fatty acid decreased from 25.53 to 20.63% in salted broiled mackerel. Soysauce group showed no reduction of PUFA with increasing storage time and showed the highest ratio of n-3/n-6 among the three groups at 10 days storage. Results reveal soysauce condiment protects against lipid peroxidation of broiled mackerel. Maillard reaction products (MRPs) found in soysauce might be responsible for the inhibitory effect and is a good condiment for extending storage life of cooked fish containing high amount of PUFA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.933-938
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• 1994

A study was amino acid contents by heating conditions of mackerel, pacific saury , yellow croaker, and brown sole investigated. In fresh fishes, total amino acid contents showed higher amount in brown sole and yellow croaker, than those of pacific saury and mackerel. The amino acid contents among the tested samples were higher Glx , leucine, lysine and arginine in order. During heating of samples the amino acid contents decreased. There appeared to be a proportional relationship of the heating temperature to decrease of amino acid. The amino acid contents of steamed samples significantly decreased than those of others. During warming and rewarming samples after storage at 4$^{\circ}C$ for 24 hours , amino acid contents slightly decreased.