• Food Science and Preservation
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• v.18 no.5
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• pp.729-738
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• 2011

This study was conducted to investigate the effect of extruded pellets (EP) containing different levels of protein (51%-55%) and lipid (9%-15%) on flesh quality of flounder (Paralichthys olivaceus) comparing with raw fish-based moist pellet (MP). Two replicate groups of 40 fish per each tank (initial mean weight 106 g) were fed one of three experimental EP (EP1, EP2 and EP3) containing different protein and lipid levels, a commercial EP (EP4) and MP for 16 weeks. Moisture content of fish fed MP was significantly higher than that of fish fed all EP. Significantly higher contents of 16:1n-7, 20:4n-6, 20:5n-3 and lower 18:2n-6 were observed in fish fed EP4 and MP compared with fish fed EP1, EP2, EP3. The 22:6n-3 content was not significantly different among all groups. Taurine content of fish fed MP was significantly higher than that of fish fed all EP. Asparagine content of fish fed EP1 was significantly higher than that of fish fed EP2, EP, EP4 and MP. Significant difference were observed in lysine and serine contents of fish fed experimental diets. In nucleotides and their related compounds, ATP and AMP content was not affected by diets. Significant difference were observed in IMP contents of fish fed experimental diets. Textural properties, no significant difference was observed among the fish groups fed different diets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.720-726
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• 1995

Chemical components relevant to the characteristic taste of the Korean native persimmon(Diospyros kaki, Thumb) leaf tea were analyzed. Samples were processed by using three different methods ; SHT(steamed and then hot-air dried), DHT(dried in the shade, steamed and then hot-air dried) and RHT(roasted and then hot-air dried). The components analyzed were general compositions of dried perisimmon leaves and extracted solution. The composition of moisture, ash, crude lipid and total nitrogen did not show significant variation among different processing methods of the persimmonleaf tea. The contents of caffeine, tannin and vitamin C in persimmon leaf tea were in the range of $178.4~209.8{\mu}mol/g$, 29.1~38.5mg% and 325.3~2084.7mg%, respectively. The vitamin C content was significantly higher in the RHT than other treatments. The contents of caffeine, tannin and vitamin C in the tea extracted solution were in the range of $101.5~130.1{\mu}mol/g$, 15.4~25.9mg% and 111.0~1274.3mg%, respectively. The vitamine C in the tea solution was the highest in the RHT treatment and 61.1% of vitamin C in the leaf tea was extracted out in these processing methods. The major amino acids contained in the leaf tea were in decreasing order glutamic acid, aspartic acid, leucine and phenylalanine, these four amino acids consisting 38.9~39.8% of the total amino acid contained in the persimmon leaf tea. The major amino acids contained in the tea solution were glutamic acid, proline, histidine and arginine. Six kinds of 5'-nucleotides, CMP, AMP, UMP, IMP, GMP and hypoxanthine were detected and CMP was the most abundant component in fresh leaf, leaf tea and tea solution. The second highest 5'-nucleotides in both leaf tea and tea solutions were GMP, AMP and UMP in all processing method. The highest free sugar contained in the fresh leaf tea and tea solution was sucrose.

• Korean Journal of Rural Living Science
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• v.10 no.2
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• pp.60-70
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• 1999

Changes in the nutritional components of Toha-jeot, salt-fermented Toha shrimp (Caridina denticulata denticulata $D_EH_{AAN}$), which was salted with a low-salt group of 15% sodium chloride (L), a high-salt group of 23% sodium chloride (H), a 50% conventional soybean sauce group (S) during long fermentation were investigated. These three groups were refrigerated at ${4\pm}1^{\circ}C$ and then taken out for analysis at three month intervals during 9 month. Even in the process of a long fermentation, the moisture containment of Toha-jeot in group L and S is 76.0~73.6% and in group H it is 70.0%, which are similar in all three groups. In case of the salinity, there was no change in groups L, H but it was lowered in group S during the fermentation. In all groups there was no change of pH. The free amino acid contents in Toha-jeot, of which ornitine, glutamic acid, leucine, alanine, lysine and valine occupy the majority, in order of abundance, increased gradually up to six months of fermentation and decreased by nine months. But free amino acid contents of S group increased continuously during the fermentation process. Hypoxanthine was altered almost among other nucleotides. ATP was not detected, IMP and inosine had disappeared after the six months for mentation. ADP was not detected after the nine months fermentation. Monoene, polyene and n-3 fatty acids were increased and saturated fatty acids were decreased in L and H groups. However, no changes of fatty acid contents in S group during fermentation were showed. The fatty acid contents of three groups, of which $C_{18:1},\;C_{16:0},\;C_{16:1}$ and $C_{20:5}$ occupy the majority, Mineral content of Toha-jeot is mainly consisted of Na, Ca, K and Mg. In the Hunter values, the redness of L group was superior to that of other groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.48-53
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• 1995

Changes in the contents of sugar, organic acid, free amino acid and uncleic acid-related compounds of leaf mustard-Kimchi during fermentation at 5~7$^{\circ}C$ were investigated. The leaf mustard-Kimchi was formulated with 4kg leaf mustard, 120g garlic, 80g ginger, 540ml salted anchovies, 1kg green onion, 200g red pepper powder, 200g ground red pepper, 60g whole sesame and 600ml glutinous rice paste. Changes in pH and acidity were relatively slow. Major free sugars were glucose(0.13%) and maltose(0.42%), and residual sugars(0.03-0.04%) were also detected after 32 days of fermentation. Major free amino acids containing more than 26.5mg% were proline, glutamic acid, alanine and histidine. Contents of total free amino acids increased from 244.8 to 397.2mg% by 24 days of fermentation. Of non-volatile organic acid, lactic acid was the most abundant(119.3mg%), and its content increased markedly after 10 days of fermentation. Other organic acids(below 53.1mg%) observed were malic, oxalic and citric acid. Contents of nucleic acid-related compounds were high in the order of hypoxanthine(22.8mg%), IMP(8.3mg%) and GMP(6.9mg%). Hypoxanthine content increased by 10 days(27.3mg%) and decreased thereafter, while the others decreased gradually during the overall period of fermentation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.154-160
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• 1989

To obtain basic data on food components of triploid fish, we undertook the analysis of free amino acid, nucleotide, total creatinine, betaine, trimethylamine oxide(TMAO) and their related compounds in diploid and triploid carps(Cyprinus carpio). The contents of total free amino acid and its related compounds in belly and dorsal muscles of triploid carp were 346.1mg/100g and 333.4mg/100g. Histidine occupied $45.1\%\;and\;46.9\%$ in belly and dorsal muscles, and followed by taurine, lysine and glycine in order. As for the compositions of nucleotide and its related compounds in those muscles of triploid carp, IMP were revealed $73.9\%\;and\;65.8\%$ of total nucleotide and its related compounds. The major component of the other organic base in those muscles of triploid carp was total creatinine, but betaine and TMAO were poor. The contents of taste compounds such as free amino acid, nucleotide, total creatinine, betaine, TMAO and their related compounds were less in triploid carp than in diploid carp of nonspawning season, while were more in triploid carp than in diploid carp of spawning season. Total amino acid contents were more in diploid carp of nonspawning season than in triploid carp, but mineral contents were more in triploid carp than in diploid carp of spawning season. Therefore, it is believed that triploid carp is very worthy for a tasty and nutritional food source.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.1-16
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• 1981

Fermented trepang entrails, Stichopus Japonicus, is widely used and occupied an important position in foods of this country. But little study on its taste compounds has been reported. This study was attempted to establish the basic data for evaluating taste compounds of fermented trepang entrails. Changes of free amino acids, free sugars, nucleotides and their related compounds as taste compounds during the fermentation of trepang entrails were analyzed by amino acid autoanalyzer and high speed liquid chromatography. Glutamic acid, alanine, glycine and proline were dominant amino acid in the fresh extracts, having 32.3%, 16.4%, 12.0% and 10.5% of the total free amino acid content, respectively. The content of leucine, valine, phenylalanine, isoleucine, methionine and tyrosine were low. The free amino acid were not changed in composition but changed in amounts during the fermentation of trepang entrails. Glutamic acid, alanine, glycine, proline, lysine, arginine and leucine were abundant in both fresh sample and fermented products. Free sugars in fermented trepang entrails, the results showed that galactose(933.7-988.0 mg%) was dominant and the content of arabinose, xylose were 78.7, 55.2-771mg% on moisture and salt free base respectively but glucose was detected in trace amount. Nucleotides and their related compounds were increased during the fermentation and hypoxanthine(47.1-$62.5{\mu}mole/g$, on moisture and salt free base) were dominant, IMP was abundant in fermented trepang entrails. TMA was increased while TMAO was decreased during the fermentation. The content of TMAO nitrogen in fermented trepang entrails was 30.0mg% on moisture and salt free base. The content of betine was increased during the fermentation and was ranged from 734.2 to 934.2mg% on moisture and salt free base. It is believed that such amino acids as glutamic acid, alanine, glycine, lysine, proline, arginine, leucine, such free sugars as galactose, arabinose, xylose, glucose, such nucleotides and their related compounds as IMP, hypoxanthine play an important role as taste compounds in fermented trepang entrails.

• Food Science and Preservation
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• v.20 no.3
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• pp.404-418
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• 2013

This study was conducted to investigate changes in the physicochemical properties (proximate compounds, reducing sugar, organic acid, ATP and related compounds, and free amino acid) of beachu kimchi (BK) with octopus, abalone, squid and webfoot octopus added during its storage at $4^{\circ}C$ for 35 days. The crude protein content of the seafood Kimchi, 1.98~3.41%, was higher than that of the BK. The organic acid level did not significantly differ in the four kinds of seafood during their fermentation, and their malate and succinate contents decreased while their lactate content increased. The levels of the ATP and related compound substances of the hypoxanthine contents were high but decreased during their fermentation. However, $3.40{\mu}mol/g$ of IMP was detected in the Kimchi with octopus added; $0.67{\mu}mol/g$ in the Kimchi with abalone added; and $1.80{\mu}mol/g$ in the Kimchi with squid added after they were fermented for 21 days, but the same were not detected in the BK. The taurine and ${\gamma}$-amino-n-butyric acid contents of the free amino acids in the seafood Kimchi were approximately two to 10 times and 1.5 to three times higher than in the BK, respectively.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.8-17
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• 1985

Followings are the obtained results from the experiment of changes in content of proximate composition, free amino acid and nucleotides in soup prepared from beef brisket, leg bone, tripe and small intestine according to the diverse heating times-3, 6, 12, 18, 24, 30 hrs. The content of moisture in each sample is decreased from 97∼99％ in 8 hours heating to 95∼97% after heating 30 hours. On the contrary, the content of crude protein and crude fat are gradually increased in proportion to the length of heating times and it showed a rapid increasement when it was boiled 6∼12 hours long. We can extract the most protein from the soup stock of tripe among all samples ana the most crude fat from the leg bone. The contents of free amino acids is gradually increased in proportion to the length of heating times. Especially after being boiled longer than 18 hours it is increased obviously. In the soup stock prepared from the brisket, the lysine and alanine were contained the most. In leg bone soup stock, glutamic acid and histidine were extracted the most but bone soup stock, glutamic acid contents were decreased a little in longer heating. In the soup stock of tripe, glutamic acid which is contained very little in a raw material was extracted more as increasing times. In the soup stock of small intestine, lysine and glutamic acid were extracted the most. The least content in free amino acid from each sample was cystine which is sulphur-containing amino acid. These result suggest that, in order to get enough extraction of amino acid, crude fat, 18 hours heating is the most useful while 5’-IMP, which is the taste compound of meat, is extracted at 3 hours heating.

• 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.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.437-443
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• 1998

This research is to establish the basic data of the nutritive value and improve our diet. In the part of the leaf and stem of the wild and cultivated horned rampion (Phyteuma japonicum Mig), the components such as chemical compositon, vitamin C, free sugar, mineral, nucleotide and its related compounds, composition and free amino acid were analyzed one after another. Content of the crude lipids and proteins was determined much higher in its wildness than in its cultivated horned rampion; while, that of carbohydrates was higher in the former than in the latter. The content of vitamin C was retained higher in the leaf than in the stem horned rampion. And the content of calcium among the detected minerals was outstanding in all of the samples collected, and potassium and magnesium was the next ones in its order. The main components of free sugars in both the wild and cultivated horned rampion were glucose and fructose, and their content was higher in the stem than in the leaf. Nucleotide and its related compounds were identified with 5 kinds of nucieotides such as CMP, UMP, IMP, AMP and hypoxanthine (Hx), and the content of Hx and AMP was the highest I the wild and cultivated samples, respectively. In the composition amino acid of the wild horned rampion, glutamic acid, aspartic acid and phenylalanine was outstandingly abundant; while, such amino acid as methinone and proline was small and besides cysteine couldn't be detected in the stem. Total amounts of composition amino acid in the leaf was 2118.0 and 1120.1mg% in the wild and cultivated sample, respectively. In the free amino acid of horned rampion, the total amount ranged from 8.5 to 50.1mg.%, which were lower level than that of composition amino acid. But the number of free amino acid was 29 kinds, which was bigger in its number than that of composition amino acid detected 17 kinds.