• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.21-29
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• 1988

This study was carried out to develop the powdered Katsuobushi (a kind of boiled, smoked, and dried fish product which is used for seasoning soup as it is.) using skipjack as a natural flavoring substance. The processing conditions of the powdered Katsuobushi and the changes of taste compounds during processing of the products were examined. In preparation of the powdered Katsuobushl, frozen skipjack was thawed, beheaded, gutted, filleted and then sliced to 1cm of thickness. The silted meats were boiled in skipjack extract for 20 minutes, and then it was smoked for, 3 times to $10\~12\%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked - dried meats were followed to be 50 mesh of particle size. The effect of slicing and boiling in skipjack meat extract on enhancing flavor and on preventing lipid oxidation of product during processing were observed. The moisture content and crude lipid content of the powdered Katsuobushi was in the range of 11 to $12\%$ and 4.3 to $4.8\%$, respectively. The taste compounds of the product were nucleotides and their related compounds, 1135.8mg/100g ; free amino acid and related compounds, 2210.2mg/100g ; non-volatile organic acids, 1148.0mg/100g ; and total creatinine. 592.1mg/100g on dry basis, and small amount of betaine and TMAO. The major elements of mineral in the product were found to be K, Mg, Na, and Ca. The content of IMP was 542.0mg/100g, and major free amino acids were found to be histidine, anserine, taurine, carnosine and alanine of which occupied to $83.6\%$ of total free amino acids. In non -volatile organic acids, major ones were lactic acid, succinic acid, pyroglutamic acid and $\alpha-ketoglutaric$ acid. From the results of the chemical experiments and sensory evaluation, we may conclude that the flavor of the product from present experiment is more desirable than that of conventional products although the processing time used were much shortened than that of conventional method, and it can be commercialized as a seasoning powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.267-273
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• 2010

The objective of this study was about physicochemical characteristic of puffer muscle and skin to promote the utilization of puffer as fish protein. In proximate composition, crude protein of dried puffer muscle and skin powders were 89.5% and 82.7%, respectively. Skin powders had higher lipid contents than muscle powders. Ash contents of muscle powders were higher than those of skin powders. In nucleotides and their related compounds, the contents of nucleotides were in order of IMP and ADP. The contents of saturated fatty acid in puffer muscle (83.9%) was higher than skin powders (66.3%). Oleic acid, mono-unsaturated fatty acid, in skin powder (25.9%) was higher than in muscle powders. Seventeen kinds of composition amino acids were detected in muscle powders, while 16 kinds of amino acids were found in skin powders. Total contents of amino acid in muscle powders (83,739 mg/100 g) were higher than those of skin powders (75,361 mg/100 g). In the muscle powders of puffer, glutamic acid was the highest amino acid with the concentration of 13,707 mg/100 g, and was in order of aspartic acid, lysine, leucine, arginine, alanine, valine and glycine. In skin powders, glutamic acid was the highest content with 14,843 mg/100 g followed by proline, alanine and arginine. Twenty five kinds of free amino acids were detected in dried muscle powders, while 22 kinds of free amino acids were found in dried skin powders. Taurine of dried puffer muscle and skin powders was the highest free amino acid with the concentration of 554.4 mg/100 g and 153.6 mg/100 g, respectively. The contents of total free amino acids of dried muscle powders were higher than those of dried skin powders. Especially, cysteine was only detected in dried muscle with the content of $159.3\pm1.8$ mg/100 g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.117-124
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• 1984

Sarine scrap usually comprises about $40\%$ of the raw fish in processing. The purpose of this study is to establish the desirable methods for proteinaceous materials from the sardine scrap through autolysis or enzymatic digestion and to convert them into useful by-products such as sardine sauce. Sardine scrap was chopped and mixed with equal weight of water, and be hydrolyzed them by autolysis and/or by addition of commercial proteolytic enzyme and various concentrations of sodium chloride. The optimal conditions for hydrolysis of sardine scrap were revealed in temperature at $55^{\circ}C$ and 4 hours digestion with bromelain($0.4\%$) and commercial complex enzyme ($6.0\%$), and those conditions were also applicated in autolysis. The maximum hydrolyzing rate of protein and released amino nitrogen were $82.5\%,\;5.2\%$ through autolysis, $84.3\%,\;5.8\%$ by bromelain digestion and $92.5\%,\;5.9\%$ by complex enzyme, respectively. In the products prepared from sardine scrap through autolysis or bromelain digestion, hypoxanthine was dominant, as $17.4 {\mu}mole/g$, dry matter for autolysis and $16.0 {\mu}mole/g$, dry matter, for bromelain digestion among the nucleotidcs and their related compounds, respectively. The abundant free amino acids were leucine, glutamic acid, lysnie, valine and alanine. The contents of those amino acids were $51.3\%,\;48.3\%$ of the total free amino acids, respectively. And the contents of 5'-IMP and TMAO were negligible but total creatinine was developed in value from $9.2\%\;to\;10\%$ of total extracted nitrogen. The flavor of sardine sauce prepared from sardine scrap by autolysis or enzyme digestion were not inferior to that of traditional Korean soy sauce by sensory evaluation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.97-106
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• 1984

The Antarctic krill, Euphausia superba, is drawing attention over the world as the largest source of unutilized proteins in the ocean. For the use of krill as a human food, processing conditions of krill sauce by autolysis and/or commercial proteolytic enzyme digestion were examined. The krill was chopped and mixed with equal weight of water, and hydrolyzed by autolysis and/or commercial proteolytic enzyme digestion. The optimal conditions for hydrolysis of krill were $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by autolysis, $52.5^{\circ}C$, pH 6.3, 3hours by bromelain (0.5 %) digestion, and $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by commercial complex enzyme (5 %) digestion, respectively The maximum hydrolyzing rate of protein were 83.2 % by autolysis, 89.7 % by bromelain digestion, 92.7 % by commercial complex enzyme digestion. After krill meat hydrolyzed by autolysis at optimum condition, inactivated at $100^{\circ}C$ for 20 minutes and filtered with Buchner funnel. Two kinds of products were prepared with krill hydrolysate and preservatives: one contained 10 % of sodium chloride and 0.06 % of benzoic acid and the other 10 % of sodium chloride and 3 % of ethyl alcohol. These products were filled in the sterilized glass bottle and sealed. The pH, volatile basic nitrogen, amino nitrogen, color value (L, a and b values) and viable counts of bacteria were determined during storage at $37^{\circ}C$. The results showed that the products could be preserved in good condition during one month at $37^{\circ}C$. As a method to reduce the sodium level in krill sauce, it is convinced that sodium chloride could be replaced half in partially by potassium chloride. In the products prepared from krill by autolysis, bromelain or commercial complex enzyme digestion, hypoxanthine and 5'-IMP were abundant among the nucleotides and their related compounds as 15.3-20.4 ${\mu}mole/g$, dry solid, 2.2-2.5 ${\mu}mole/g$, dry solid, respectively. The abundant free amino acids were lysine, leucine, proline, alanine and valine. The contents of these amino acids were 67.4 %, 69.4 %, 69.8 % of the total free amino acids of each products. And TMAO, betaine and total creatinine were low in contents. The flavor of krill sauce prepared from krill by autolysis or enzyme digestion was not inferior to that of traditional Kerean soy sauce by sensory evaluation.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.440-449
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• 2007

This study was conducted to investigate the compositions of different cuts of Hanwoo bull beef. 10 cuts [Abjin (short plate), Bosup (top sirloin), Cheggt (striploin), Dngsim (loin), Guri (chuck tender), Hongduke (eye of round), Moksim (chuck roll), Sulgit (bottom round), Udoon (top round), Yangi(brisket)] were prepared from 10 Hanwoo bulls (-24 month old) slaughtered during 3 consecutive days. There were no significant differences in the calorie contents among the 10 cuts (p<0.05). In cholesterol content, Hongduke was significantly lower (26.74 mg/100 g) and Abjin was significantly higher (31.08 mg/100 g) than the other cuts (p<0.05). Free amino acid analysis revealed that there were high contents of glutamate (94.33-216.36 mg/100 g) and alanine (154.88-200.31 mg/100 g), followed by arginine, phenylalanine and lysine in the 10 cuts. In addition, Abjin, Bosup, Cheggt, Hongduke, Sulgit and Udoon had significantly higher inosine monophosphate (IMP) contents than Dngsim or Moksim (p<0.05). Inosine contents were highest in Bosup and Sulgit, whereas hypoxanthine contents were highest in Guri (p<0.05). Total collagen contents were significantly higher in Abjin followed by Yangi, Guri and Moksim (p<0.05). With regard to fatty acid composition, Dngsim had significantly higher $C_{18:0}$ than the other cuts, and Udoon had significantly higher $C_{20:4n6}$ than the other cuts (p<0.05). Total contents of saturated fatty acids (SFA) were significantly higher in Abjin, Dngsim and Yangi, whereas total contents of unsaturated fatty acids (UFA) were significantly higher in Hongduke than the other cuts (p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.41-51
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• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.

• Journal of Aquaculture
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• v.15 no.3
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• pp.157-163
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• 2002

Thirteen groups, each consisting of 25 juveniles (0.64 g) of the Korean rockfish, Sebastes schlegeli were reared in aquaria after period of one week conditioning. Each group was fed with one of the 13 diets at the rate of 7~10% body weight (on a dry-matter basis) 2 times a day for 6 weeks. Each diet was supplemented with one of the following amino acids at 3g/kg diet: Alanine (Ala), Arginine (Arg), Glycine(Gly), Glutamate (Glu), Histidine (His), Isoleusine(Ile), Lysine (Lys), Methionine (Met), Phenylalanine (Phe), Proline (Pro), Threonine (Thr), Tryptophan (Trp) or Valine (Val). Groups fed with Pro, Thr, Met or Gly-supplemented diet showed significantly (p<0.05) higher weight gain and faster specific growth rate than the groups fed on other diets, while those fed Pro, Thr, Met or Gly were not significantly different each other(P>0.05). Feed efficiency (FE) of fish fed Pro was significantly higher than those fed the other diets except that fed Thr (P<0.05). However, there was no significant difference between FE of fish fed Pro and Thr, and among FE of fish fed Thr, Met and Gly (P>0.05). The requirement of rockfish is higher for Met and Thr. Extra Pro and/or Gly may also stimulate biosynthesis of the nucleic acids (IMP, GMP) which are known as the feed stimulant in fish.

• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.78-88
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• 2013

Marinated beef galbi is a traditional Korean dish cooked with soy sauce, pear juice, onion, sesame oil, and sugar. However, there are many differences in beef galbi, including flavor and physicochemical aspects, depending on cooking conditions. Therefore, the physicochemical characteristics of marinated beef galbi prepared through various recipes was evaluated for its effects on pH, texture, aging, proteolysis, heating conditions, cooking time, and flavor compounds (pyrazines, IMPs, or FAAs). There were significant differences in salt concentration (0.8~3.03%), pH (4.89~6.22), and solid soluble contents (1.34-6.31 Brix) between recipes in this study. In the Pearson assay for sensory evaluation, overall preference correlated well with texture (a well-known sensory attribute in meat evaluation). Controlling the pH of meat through soaking in lemon solution, alkali water, phosphate, and baking powder solution, improved water holding capacity as much as 9 to 15% compared with the control. The myofibril index (MFI) of marinated meat stored at $4^{\circ}C$ increased 32% with 24 hours of aging and reached 39% at 48 hours of aging, and its fragmentation was observed through microscopy. SDS-PAGE showed hydrolysis of acid-soluble collagen by the pear juice, possibly related to meat tenderness. On the basis of surface temperature, the cooking time was estimated to be 8 minutes with pan heating at $170^{\circ}C$, 6 minutes at $270{\sim}300^{\circ}C$, and 4 minutes with charcoal at $700{\sim}900^{\circ}C$. Different pyrazine compounds, such as 2-methyl-3-phenylpyrrol(2,3-b) pyrazine (the typical product of the browning reaction) was mainly detected, and IMP (one of the main taste compounds in beef) was in higher amounts with the charcoal treatment, potentially related to its flavor preference among treatments. Our results demonstrate an effective case study and cooking system for beef galbi.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.75-83
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• 2001

This study is to investigate biochemical compositions of two species of marine microalgae, Chlorella ellipsoidea of Chlorophyta and Tetraselmis suecica of Prasinophyta, and to assess their potential antimicrobial activities. Crude protein, lipid and carbohydrate for C. ellipsoidea were $43.15\%$, $12.63\%$ and $13.09\%$, respectively, and those for T. suecica were $44.95\%$, $4.80\%$ and $24.05\%$, respectively. The major amino acids of the two micro algae were aspartic acid, glutamic acid, glycine, alanine, valine, leucine, lysine and proline, and no significant difference between the amino acid compositions of both micro algae was observed. The major sugars for both microalgae were glucose, galactose and mannose, and glucose contents showed the highest level, $58.70\%$ for C. ellipsoidea and$57.86\%$ for T. suecica. The major mineral contents of both micro algae for 100g were Ca (3,114mg in C. ellipoidea and 3,389mg in T. suecica) and followed by Na (2,881mg), K (548mg) and Mg (545mg) for C. ellipsoidea and Na (1,832 mg), Mg (1,510mg) and K (548mg) for T. suecica. In the content of ATP-related compound, hypoxanthine in C. ellipsoidea and IMP in T. suecica were absolutely dominant compounds. The highest content of fatty acid in C. ellipsoidea was 20:4, $27.15\%$ and that in T. suecica was 18:3 (w-6), $18.10\%$. In case of physiologically important polyunsaturated fatty acids like eicosapentaenoic acid (20: 5) and docosahexaenoic acid (22: 6), both microalgae possessed just trace amounts but was rich in arachidonic acid (20: 4). Vitamin content in both microalgae was significantly high in choline and inositol. In antimicrobial activity by water- and fat-soluble fraction of the micro algae, hexane extract in the fat-soluble fraction of C. elliposidea inhibited the growth of Bacillus subtilis by $96\%$ bactericidal activity and tetrachlorocarbon extract of T. suecica indicated relatively excellent antimicrobial activity $(81\%\;bactericidal\;activity)$ against Escherichia coli. Hot water extract among water-soluble fraction of both micro algae almost suppressed the growth of Staphylococcus aureus by $96\%$ bactericidal activity.

• Journal of the Korean Society of Food Culture
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• v.17 no.4
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• pp.482-495
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• 2002

Changes in ATP and related compounds, TMAO, TMA, creatine and creatinine were analyzed to establish the processing conditions for rapid- and low salt-fermented liquefaction of anchovy(Engrulis japonica) extracts during fermentation. Experimental sample A: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 10% NaCl. Sample B: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 13% NaCl. Sample C: chopped whole anchovy adding 13% NaCl. Sample D: whole anchovy adding 17% NaCl. ATP, ADP, AMP and IMP were broken down during fermentation period, while inosine and hypoxanthine or hypoxanthine were detected in each fermented liquefaction of anchovy. However the amounts of them were varied from collection to collection according to the pretreatment methods. Possibly ATP and their related compounds will not make a great contribution to the umami taste in fermented liquefaction of anchovy. The contents of TMAO were decreased during fermentation period, ranging from 3 to 15 mg/100g in the fermented liquefaction of anchovy after 180 days. The TMA contents were increased slowly during fermentation period, ranging from 60 to 114 mg/100g in the 180 days specimens, however their contents were varied from sample to sample. The contents of creatine and creatinine were increased during early fermentation period, and then they were decreased in the last period. As for distribution of nitrogen in the anchovy extracts, the contribution of creatine and creatinine to the extractive nitrogen was occupying 6.8, 5.7, 4.6 and 5.7% in the experimental sample A, B, C and D, respectively. The contribution of ATP and related compounds to the extractive nitrogen was occupying 2.1, 2.4, 2.2 and 2.7% in the experimental sample A, B, C and D, respectively. The contribution of TMAO and TMA to the extractive nitrogen was very low as they are occupying $0.7{\sim}1.2%$ in the four experimental samples.