• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1069-1075
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• 2009

Conger eel (Conger myriaster) is used as a well-being food in the foodservice industry in Korea. We analyzed not only the proximate composition but also the taste components affecting conger eel, which are fatty acids, nucleotides, amino acids, etc. Concerning the composition, the crude lipid was the lowest in summer at 3.2%, which is considered due to spawning period. The major fatty acids were $C_{16:0},\;C_{16:1},\;C_{18:0},\;C_{18:1},\;C_{20:5},\;and\;C_{22:6}$. The $C_{18:1}$ content was the highest among the fatty acids and the content varied between 36.76 and 45.11% by season. Seasonal change in the content of poly-unsaturated fatty acids was increased from spring to winter in conger eel. Among the nucleotides, the contents of IMP (3.617$\sim$5.524 $\mu$mol/g) and Hx (0.913$\sim$2.238 $\mu$mol/g), which is closely related to taste, and the concentrations of IMP and Hx were the highest (7.219 $\mu$mol/g) in winter, and HxR (0.625$\sim$1.652 $\mu$mol/g) was higher than ATP (0.058$\sim$0.083 $\mu$mol/g), ADP (0.145$\sim$0.161 $\mu$mol/g), and AMP (0.166$\sim$0.179 $\mu$mol/g). In conger eels, the major total and free amino acids were glutamic acid (14,178.7$\sim$7,802.6 mg%), aspartic acid (4,669.2$\sim$8,259.0 mg%), lysine (4,198.3$\sim$7,540.8 mg%), leucine (3,843.6$\sim$6,782.1 mg%), and histidine (199.6$\sim$644.4 mg%), glycine (94.8$\sim$152.2 mg%), alanine (35.3$\sim$71.2 mg%), glutamic acid (44.1$\sim$70.6 mg%), respectively, but the concentration of amino acids was different by season. The content of free amino acids, which is related to the taste component, was detected as high in summer and winter at 1179.2 and 1,605.2 mg%, respectively.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.700-707
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• 2013

The purpose of this study was to monitor physicochemical changes of olive flounder (Paralichthys olivaceus) muscle by iced water pre-treatment. Moisture content, crude fat content, nucleotide content, texture (hardness and toughness), and rigor mortis were assessed. The sensory evaluation was performed with a nine-point hedonic test. K-values, a parameter of fish flesh freshness, were also calculated from the content of nucleotides and their corresponding decomposition products. Pre-treatment of flounder flesh with iced water was found to be fresher compared to the control, as determined by a difference in the K-values. Iced water pre-treatment hastened postmortem stiffness, as judged from the rigor index, and increased inosine monophosphate (IMP), which is known to be a savory taste compound, more quickly as adenosine triphosphate (ATP) degradation proceeded.

• Korean Journal of Poultry Science
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• v.51 no.1
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• pp.11-19
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• 2024

This study was conducted to evaluate the potential of using laying hens as meat type chickens. Male broiler (Ross 308, R3), laying hens (Hy-Line Brown, HL), and Korean native chickens (Hanhyup-3, H3) were used, and 100 heads of each were prepared. Carcass characteristics, meat quality, and sensory quality characteristics were compared as analysis items. The rearing environment and feed for all treatments were identical to the broiler rearing manual, and the lighting system was maintained at 23L:1D. Feed and water were provided ad libitum. The test ended when the average weight of each treatment group reached 1.5 kg, and individuals of similar weight were randomly selected and compared. As a result of this study, the live weight of the selected individuals was approximately 1.5 kg, which was similar for all treatments (P>0.05). However, carcass weight and ratio and breast meat production were highest in R3, while HL had higher ratios of legs, wings, and neck (P<0.05). The H3 group showed high pH and WHC levels and low cooking loss, and R3 improved chicken meat color (P<0.05). In particular, the fat content in meat was lowest in HL (P<0.01). Nucleic acid substances ATP, Hx, ADP, AMP, and INO were abundant in R3, and IMP content was highest in HL (P<0.05). In sensory evaluation, all treatments showed similar characteristics and overall preferences (P>0.05). Based on the findings, it appears that HL, a male laying hen, produces meat with unique characteristics such as low fat content and high IMP content.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.772-787
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• 2000

In this study, evaluation on the loaches from the various sources was carried out in respect of their taste compounds. The samples were classified by local, season and growing condition and evaluated in terms of composition, the refuse, contents of nucleotides and their related compounds, total and free amino acid, organic acid and fatty acid. Evaluation on the compositions revealed the fact that, in terms of the local, the imported loach contain a low level of fat and high level of ash, in comparison with Korean loach; in terms of growing condition, cultured loach contains a high level of fat and low level of moisture, in comparison with wild loach; and in terms of the season, the summer loach contains less moisture than the fall loath; but as for the contents of other component, the summer loach was superior. As for the refuse, the imported loach had a greater refuse than the Korean loach. In the growing condition, the wild loach had lower value than the cultured loach. There was no substantial difference in each season. Also nucleotide and these related compounds were detected in all of the samples, while ATP was not found. The content levels of such detected compound did not show a substantial difference in each condition. However, generally, the imported loach was poor in such compound and all of the samples were high in IMP. The samples were high in total amino acids. The local and growing conditions showed no substantial difference, while in the season, the summer loach had a higher content of total and essential amino acid than the fall loach. As for the contents of free amino acids, similar distribution of the composition was shown in each sample, even though there was little difference in their constituents. Also, total content of free amino acid varied with the conditions of the samples. As for total content of organic acid and the distribution of the composition, there was a little difference between each condition. In the season and growing condition, the summer loach was high in organic acid. As for the distribution of the fatty acid compositions, there was no substantial difference between each condition and each sample. In the case of the wild loach, the summer loach was high in ${\omega}-3$ polyunsaturated fatty acid and the fall loach was high in essential fatty acid. Similarly, in the case of the imported loach, the summer loach was high in ${\omega}-3$ polyunsaturated fatty acid and the fall loach was high in essential fatty acid.

• Journal of Nutrition and Health
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• v.14 no.1
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• pp.16-25
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• 1981

Commercially available duck-meat was subjected to proximate analysis. On a wet basis, the duck-meat contained 62.87, 17.05, 19.06 ana 1.02 percent of moisture, crude fat, crude protein and ash, respectively. Almost all the essential amino acids contained in the duck-meat protein, ana the tryptophan was the limiting one by amino acid analysis of GLC. An analysis of the fatty acid composition by GLC showed a relatively high concentration of oleic acid. There was also a considerable content of linoleic acid. The content of polyunsaturated fatty acids of duck-meat was 70.9% and the P/S ratio of fatty acids was 3.4. The cholesterol content in duck-meat was determined to be approximately 70. 5mg/100g ofm sample. According to blood analysis, it was understood that the content of phospholipids was relatively high, particulary in lecithin. ATP-phosphorus, at the higher temperature, was released faster than at the lower temperature, by two hours after postmortem. The ATPase activity of Myogibril was inhibited at the relatively high concentration of added EDTA and metallic ions, but the activity was very high in the lower concentrations. According to the cooking conditions, boiled duck-meat showed good digestion by pepsin. It was understood that the digestibility of duck meat was relatively high, so the duck-meat protein is good source of animal protein. Therefore, it is able to be recommended that duck-meat is good nitrogen source animal food.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.59-64
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• 2015

Lactic acid-producing bacteria such as Lactobacillus spp. function to ferment carbohydrates and produce ATP. Such Lactobacillus spp. are used for the production of commercial yogurts. Lactobacillus spp. are beneficial to the intestinal tract, and Lactobacillus acidophilus-containing yogurts have received considerable attention because of their preventive effects against early-stage cancer of the large intestine. In this study, lactic acid-producing bacteria were cultured from three different groups: commercial solid yogurt (for eating), commercial liquid yogurt (for drinking), and Lactobacillus acidophilus-containing yogurt. We first determined the optimum culture conditions for Lactobacillus spp. and then analyzed turbidity and pH in order to compare the growth abilities and lactic acid-production capacities among the groups. Finally, high-performance liquid chromatography was used to measure the lactic acid content in the culture supernatants, and the antibacterial activities against Staphylococcus aureus and Escherichia coli were compared among the three groups. The optimum culture conditions for Lactobacillus spp. were MRS medium at $25^{\circ}C$, for 24 h. The highest turbidity was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Similarly, the highest lactic acid production ability was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Culture supernatants from the three groups did not show any antibacterial activity towards S. aureus; however, supernatants derived from L. acidophilus-containing yogurt resulted in a 1.8 mm inhibitory zone against E. coli in a paper disk diffusion test. These results revealed the high level of lactic acid-production capacity and antibacterial activity in L. acidophilus-containing yogurt.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.185-190
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• 1993

Tilapia cultured in fresh water were acclimated in sea water with daily increase of $5%_{\circ}$ of salinity and it was completely terminated at the 7th day (0 week). Each three tilapia acclimated were examined weekly based from 0 week to elucidate changes of chloride cells in gill, mineral contents and physical properties in muscle and biochemical characteristics in myofibrils. Chloride cells existed in gills were gradually developed in number and size by acclimation to sea water and became to almost constant state at the third week. Shearing value, compressing strength and content of minerals such as Mg, Na and K in muscle were showed remarkable increase by acclimation to sea water in comparison to those of muscle from tilapia reared in fresh water. Myofibrillar $Mg^{2+}-,\;Ca^{2+}-$ and $K^+(EDTA)-ATPase$ activities of tilapia acclimated in sea water also increased showing significant statistic difference (p<0.01) from those of tilapia reared in fresh water However. thermostability of myofibrils was dropped by acclimation to sea water. The increase of shearing value and compressing strength in the muscle of tilapia by acclimation to sea water would be attributed to the increase of myofibrillar ATPase activities which act to accelerate the decomposition rate of ATP. Therefore, it is suggested that this phenomenon associated with muscle contraction could be brought an improvement of texture of tilapia acclimated in sea water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.666-673
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• 2012

The effects of bamboo salt on quality of traditional Jeju fermented fish, $Jari-Jeot$ were investigated. Bamboo salt suppressed the activity of microorganism more effectively than salt. pH of $Jari-Jeot$ prepared with both of salt and bamboo salt increased gradually during storage. During fermentation there were little changes in color between salt and bamboo salt fermented $Jari-Jeot$. Salinity did not show obvious differences between samples. Water content increased in salt and bamboo salt fermented $Jari-Jeot$ due to the decrease of salinity. Hypoxanthine was the major component of ATP-related compounds in both salt and bamboo salt fermented $Jari-Jeot$. In $Jari-Jeot$ fermented with salt or bamboo salt, lysine, glutamic acid, proline, alanine, leucine, isoleucine, arginine and histidine were dominant amino acids which marked 69%~74% of total free amino acids, while trace amounts of taurine were detected.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.466-472
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• 2006

In order to develop materials of crab-like flavorant, taste compounds including physicochemical characteristics were analyzed in red snow crab cooker effluent(RSCCE) and hepatopancreas. The $30\;^{\circ}Brix$ was a suitable condition in from 1.5 to $40\;^{\circ}Brix$ RSCCE by sensory evaluation. Lactic acid and succinic acid were major compounds in non-volatile organic acids detected in both $30\;^{\circ}Brix$ RSCCE and hepatopanceras. The 5 compounds such as AMP, HxR, IMP, ATP and GMP were major in ATP related compounds of $30\;^{\circ}Brix$ RSCCE, whereas 3 compounds including IMP, GMP and Hx in hepatopanceras. The content of total free amino acids in hepatopancreas was 5.6 times higher than in $30\;^{\circ}Brix$ RSCCE. The major compounds in $30\;^{\circ}Brix$ RSCCE were followed by methionine, lysine, arginine, valine, histidine, alanine, hydroxy proline, and glycine in that order, whereas methyl histidine, leucine, alanine, glutamic acid, glycine, valine, threonine, taurine, isoleucine, and serine were followed in hepatopancreas. By adding 0.5%(w/w) hepatopancreas in $30\;^{\circ}Brix$ RSCCE, crab meat-like odor was kept high level by sensory evaluation.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.541-546
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• 1992

In order to develop low salt fermented hen clam sauce with high stability, the effects of citric acid pretreatment and fermentation temperature were examined. The VBN contents of surf clam sauce treated with citric acid (SCA) were lower than those of control and the same sauces added alcohol at two temperature conditions ($5^{\circ}C$ and room temperature) during fermentation. The maximum $NH_2-N$ contents of control and SCA during fermentation at $5^{\circ}C$ were 501.3 and $618.4{\sim}691.6\;mg/100g$, respectively, and the pH of those showed $5.61{\sim}6.24$ and $2.43{\sim}3.21$. The total creatine contents of control and SCA, respectively, were $36.8{\sim}27.6\;mg/100g$ ranges. As the time of treatment with citric acid was longer, the degradation of ATP, ADP and AMP in the SCA was faster. In the control, the Ala content was $19.6{\sim}23.02%$ and was highest level among all free amino acids. As fermenting term was longer, among the free amino acids, Ala and Gly were large amounts in control and SCA, respectively, and Gly was slowly increased in SCA during fermentation. As the results of organoleptic test, the tastes of SCA showed good score than control.