• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.769-776
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• 2003

Organic acids, nucleotides and their related compounds (NRCs) of kimchi prepared with salted-fermented fish products (SFFPs) and their alternatives were analyzed at each optimal fermentation (pH $4.2{\pm}0.2$, acidity $0.6{\sim}0.8%$) during fermentation at 20, 10 and $4^{\circ}C$, respectively. The pH and acidity levels of kimchi sharply decreased and increased, respectively until each optimal fermentation period. The levels of organic acids and NRCs in SFFP kimchi were affected by fermentation temperature and the type of additive. Compared with the control, organic acid levels were slightly higher in kimchi with alternative additives, as were NRC rates in kimchi with hydrolysates of oyster and Alaska pollack. Moreover, slightly higher levels of NRC were observed in kimchi with alternative additives than in kimchi with SFFPs. Consequently, these results show that fermentation temperature and the type of additive (SFFPs and their alternatives) affect not only fermentation, but the levels of organic acids and NRCs in kimchi.

• KSBB Journal
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• v.13 no.3
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• pp.295-302
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• 1998

Human Erythropoietin (EPO) gene is cloned in quail fibrosarcoma cell, QT35. Because molecular weight of EPO is similar to that of serum albumin, cell culture with serum containing medium makes purification of EPO very difficult. Using fractional factorial study, we have developed serum free medium for the recombinant QT35 cell lines, QT N4D4 and QT SY-IMP, which have cloned EPO with glutamine synthetase (GS) gene amplification system and with puromycin selective marker, respectively. Among the seven frequently used medium components, fibronectin, BSA, and EGF were the most important for EPO production. However, sufficient fibronectin supplement to the medium did not make any good attachment of QT35 to culture plate over 3 days. Therefore, to maximize EPO production, we attempted a medium-shift at confluence from serum containing medium to serum free medium(QT SFM6). Using the medium-shift protocol with QT SFM6, nearly the same productivity of EPO was achieved comparing with that without medium-shift. This result was true in both QT35 cell lines in three types of culture, i.e. T flask, microcarrier and roller bottle cultures.

• Korean Journal of Veterinary Service
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• v.19 no.3
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• pp.213-219
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• 1996

Seventy-nine strains of Enterobacteriaceae isolated from 117 slaughtered pigs (bile, urine, small intestine, cecum and rectum) in 1995 were examined for biotypes and susceptibility to 19 antibiotics with MicroScan WalkAway 40/96. The obtained results were as follows : 1. Among the twenty-two species isolated from the samples, Proteus mirabilis, E. coli and Enterobacter cloacae were commonly encountered. 2. The distribution frequency of isolates from cecum, small intestine, rectum, bile, and urine was 31(38.8%), 25(31.3%), 18(22.8%), 3(3.7% ), and 2(2.5% ), respectively. 3. A majority of isolates were sensitive to 16 antibiotics, singly or in combination. And these isolates were commonly susceptible to various antibiotics such as Cp, Ts, Azt, Caz, To, Gm, Cfz, Crm, Am and Cfx, in order. Whereas the Salmonella spp was susceptible to Cf, Ti and Pi, and Proteus mirabilis to Imp, Tim, Cft and Cz. Meanwhile, no effect was found to Cf, Ak and Cax. 4. Among the antibiotic resistant strains, a total of 17 reistant patterns was noted End of these Ak Tim 45(57.0%), Ak Am Cf Cfx Cfz Tim 8(10.1%) and Ak Ti Tim 6(7.6% ) were frequently encountered.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.366-371
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• 2004

Powder and liquid products of the seasoned and smoked fish were manufactured with small-sized skipjack tuna (Euthynus pelamis) captured in the East Sea, Korea. The property changes of nucleotides and their related compounds, amino acid, and sensory attribute during storage were analyzed. IMP content was the highest among the nucleotides and their related compounds followed by inosine in both powder and liquid products. Nucleotides and their related compounds of the powder product increased slightly as storage period increased, while those of liquid product were constant. Glutamic acid $(15.6{\%})$, aspartic acid $(10.7{\%})$, and lysine $(9.3{\%})$ were major amino acids of the power product, while histidine $(36.2{\%})$ and taurine $(10.6{\%})$ were high in the liquid product. Free amino acid contents of liquid product increased during storage periods. There was no significant difference In the concentration of nucleotides and their related compounds, and composition of free amino acid between the products with/without liquid smoke. Aroma and acceptance were good in both products, while bitterness and sweetness were poor.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.93-105
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• 2012

This study was carried out to prepare anchovy hydrolysates by using Alcalase, Neutrase and Protamex, and to investigate its quality characteristics. The major free amino acids were glutamic acid and lysine. The total amino acid content of anchovy hydrolysate were glutamic acid(12.6%), lysine(8.56%), valine(7.06%), aspartic acid(5.73%). Major nucleotides content of anchov hydrolysate were 5'-IMP (22.462 mg/100g), 5'-GMP (18.674 mg/100g) and 5'-UMP (1.25 mg/100g). Histamine content of anchovy hydrolysate was 18.1 mg/100g. These results suggested that anchovy hydrolysate could be used as a sauce of basic seasoning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.131-138
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• 1985

The preservative effect of modified-atmosphere storage on the shelf-life of packed semi-salted and dried mackerel, Scomber japonicus, was examined. The semi-salted and dried mackerel fillets were packed in laminated plastic film bags (polyester/nylon/casted polypropylene: $12{\mu}m/15{\mu}m/60{\mu}m,\;15{\times}16cm$) filled with air (control, C), nitrogen gas (N), deoxygenized air (O) prepared by using free-oxygen absorber enclosed in the bag, in vacuum(V), and stored at $5^{\circ}C$. The quality of packed sample during the storage were examined in terms of viable cell counts of bacteria, thiobarbituric acid(TBA) value, perozide value(POV), volatile basic nitrogen(VBN), trimethylamine(TMA), adenosine triphosphate(ATP) and its related compounds and sensory evaluation. The results obtained are as follows: The pH of all the samples was in the range of $6.1{\pm}0.2$, and the contents of VBN and amino nitrogen of them increased during storage. In color values, L value(lightness) decreased while a and b values (red and yellow) revealed a tendency to increase during storage. The viable cell counts of the control sample(C) increased to $3.0{\times}10^6/g$ after 15 days storage but those of the other samples(V, N and O)were in the range of $2{\sim}6{\times}10^5/g$ after 20 days storage. The content of TMA increased during storage, but the histamine content showed a little change during storage and its content of all samples were less than 16 mg/100g. The inosinic acid(IMP) was rapidly degraded while inosine and hypoxanthine increased during storage. The TBA value of the control(C) reached a peak in 9 days and then decreased gradually while that of the sample(O) showed a little change during storage. The changes in POV of all the samples during storage showed a similar tendency to the TBA value. Fatty acid composition of raw mackerel consists of $35.6\%$ of saturated acid, $30.3\%$ of monoenoic acid and $34.2\%$ of polyenoic acid. The major fatty acid of the sample products were oleic acid($C_{18:1}$), palmitic acid($C_{16:0}$), docosahexaenoic acid($C_{22:6}$). The contents of polyenoic acid such as $C_{22:6},\;C_{20:5}$ decreased during storage while the other fatty acids showed a little change. From the results of sensory evaluation, the shelf-life of the control sample(C) was about 7 days and that of sample(V), (N) and (O) was about 15 days. It was concluded that deoxygenized atmosphere(free-oxygen absorber enclosed in the bag) was a good condition for preserving the quality of semi-salted and dried mackerel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1210-1214
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• 2009

Early postmortem ATP level is known as a good predictor of pork quality. Pork carcasses were divided into two; one was electrically stimulated (ES) to simulate poor quality pork and the other was left untreated and served as a control normal pork. Fractions of longissimus were excised from carcasses regularly for 2 hours after death and deep-frozen ($-80^{\circ}C$) until analyses. The ATP level of normal untreated control pork decreased from 5.00 to 2.04 ${\mu}mole$/g within 2 hours postmortem. The decrement of ATP was approximately 60% of its initial content. In the meantime, ES poor quality pork had a more drastic rate of ATP decrease. Electrical stimulation itself decreased ATP level from 4.70 to 3.50 ${\mu}mole$/g, by approximately 25%. ATP level of ES pork dropped to 1.71 ${\mu}mole$/g within 1 hour postmortem and was further plunged to 0.26 ${\mu}mole$/g and almost exhausted during the next hour. The level of IMP increased from 0.49 to 3.17 ${\mu}mole$/g and it became the dominant nucleotide within 2 hours postmortem. Electrical stimulation prompted the increase of IMP from 0.69 to 3.19 ${\mu}mole$/g and its level went up to 6.64 ${\mu}mole$/g within 2 hours postmortem. The level of ADP also decreased from 1.45 to 0.67 ${\mu}mole$/g for 2 hours after death and ES also accelerated ADP breakdown. The AMP levels were lower than those of other nucleotides and increased from 0.16 to 0.31 ${\mu}mole$/g within 2 hours postmortem. The increase of AMP was accelerated between 60 and 90 minutes after electrical stimulation. Early postmortem electrical stimulation prompted a drastic rate of changes in contents of 4 nucleotides during 2 hours postmortem. In the meantime, the ATP levels for ES poor quality pork were much lower than those of normal pork.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.427-431
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• 2002

Alkali treatment following acidic hydrolysis (ATAH) is a commonly used practice for reducing the levels of monochloropropanediol in commercial Korean soy sauce. This study investigated the chemical compounds produced in commercial Korean soy sauce made by ATAB. The levels of amino-N, total acidity, pH, salinity and Brix of the soy sauce were 6.66%, 2.52%, 19.81%, 4.57 and 35.01, respectively. The major fatty acids were C18:2n-6, C16:0, Cl8:ln-9 and C18:3n-6. The concentration of polyunsaturated fatty acids were especially high, with of C18:2n-6 (49.8%) being the highest followed by C18:3n-6 (3.8%) and C18:3n-3 (2.4%) in that order. Among the non-volatile organic acids, the concentration of levulinic acid (1,206.28 mg/100 g) was the highest, while the taste value of citric acid was the highest. Among the ATP related compounds, IMP concentration (31.19 mg/100 g) was highest followed by AMP, hypoxanthine and GMP in that order. The concentrations of free and total amino acids in soy sauce were 6,136.94 mg/100 g and 8,702.76 mg/100 g, respectively. On the other hand, the taste value of glutamic acid, a major amino acid flavor determinant in soy sauce, was highest of all the amino acids, which is desirable since most free amino acids such as methionine, histidine and phenylalanine have a bitter taste that detracts from the flavor of soy sauce.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.285-292
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• 1993

For the enzymatic conversion of 5'-XMP to 5'-GMP, partially purified XMP aminase from Escherichia coli was coupled with the yeast, Saccharomycrs cerevisiae, capable of ATP regeneration through glycolytic pathway. In order to elevate the level of XMP aminase in E. coli, $guaB^{-}(IMP\;dehydrogenase-less)$ mutant were introduced, and the yeast used as ATP supplier was treated by some method to increase its membrane permeability. The optimum conditions for efficient conversion reaction by energy-coupled system were investigated. As the results, a CH 41, $guaB^-$ mutant of E. coli K-12, showed 2.75 fold increase in the level of XMP aminase, compared with its parent cell. And the lyophylized yeast was the most effective at the ATP supplier. The optimum temperature and pH of conversion reaction were $40{\circ]C$ and pH 7.4, and the highest conversion ratio was shown under the reaction condition of 100 mM glucose, 100 mM inorganic phosphate and 6 mM AMP. When 36 units/ml XMP aminase used under the above conditions, the amount of 60 mg/ml yeast was sufficient to be used. Under the optimum condition, 71% of 1.8 mM(65.6 mg/100 ml) 5'-XMP was converted to 5'-GMP within 8 hr.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.75-78
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• 2000

The present study was conducted for the data of toxicity and taste components of the pufferfish, Sphoeroides annulayus (bull's eye fuller), transported from Mexico. All other parts including muscle and skin were nontoxic ranging below $10\;{\mu/g$ except gonad, The amounts of IMP and ADP were $5.6\;{\mu}mol/g\;and\;2.7\;{\mu}mol/g$, and the ratio to the total ATP and its related compounds was $41.1{\%}$. The great portion of free amino acids in the muscle of the puffer was occupied by L-glycine, L-alanine, L-anserine, L-threonine and L-valine. Their amounts were $233.5 mg/100 g, 169.0 mg/100 g, 149.1 mg/100 g, 135.7 mg/100 g and 132.3 mg/100 g$. Their concentration ratio to total free amino acids were $14.28{\%},\;10.33{\%},\;9.12{\%},\;8.30{\%}\;and\;8.09{\%}$, respectively. The content was $50.12{\%}$ of the total free amino acids. In addition, the amounts of taurine and L-histidine were 119.3mg/100 g and 14,7 mg/100 g.