• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.777-781
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• 2001

The effects of gamma-irradiation on the nutritional components of some Korean soybean-based fermentation foods were studied. Doenjang (soybean paste), kochujang (red pepper paste) and chungkukjang were prepared, irradiated at 0, 5, 10 and 20 kGy, and their compositions of free amino acid, free fatty acid and organic acid were determined. Compositions of free amino acid and free fatty acid in gamma irradiated sample were stable compared to non-irradiated control. Content of citric acid and succinic acid increased, while that of malic acid decreased in the gamma irradiated chungkookjang, but there were no significant changes in organic acid composition in organic and kochujang.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.241-247
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• 2014

To investigate the underlying mechanisms of C18 fatty acids (stearic acid, oleic acid, linoleic acid and ${\alpha}$-linolenic acid) on mast cells, we measured the effect of C18 fatty acids on intracellular $Ca^{2+}$ mobilization and histamine release in RBL-2H3 mast cells. Stearic acid rapidly increased initial peak of intracellular $Ca^{2+}$ mobilization, whereas linoleic acid and ${\alpha}$-linolenic acid gradually increased this mobilization. In the absence of extracellular $Ca^{2+}$, stearic acid ($100{\mu}M$) did not cause any increase of intracellular $Ca^{2+}$ mobilization. Both linoleic acid and ${\alpha}$-linolenic acid increased intracellular $Ca^{2+}$ mobilization, but the increase was smaller than that in the presence of extracellular $Ca^{2+}$. These results suggest that C18 fatty acid-induced intracellular $Ca^{2+}$ mobilization is mainly dependent on extracellular $Ca^{2+}$ influx. Verapamil dose-dependently inhibited stearic acid-induced intracellular $Ca^{2+}$ mobilization, but did not affect both linoleic acid- and ${\alpha}$-linolenic acid-induced intracellular $Ca^{2+}$ mobilization. These data suggest that the underlying mechanism of stearic acid, linoleic acid and ${\alpha}$-linolenic acid on intracellular $Ca^{2+}$ mobilization may differ. Linoleic acid and ${\alpha}$-linolenic acid significantly increased histamine release. Linoleic acid (C18:2: ${\omega}$-6)-induced intracellular $Ca^{2+}$ mobilization and histamine release were more prominent than ${\alpha}$-linolenic acid (C18:3: ${\omega}$-3). These data support the view that the intake of more ${\alpha}$-linolenic acid than linoleic acid is useful in preventing inflammation.

• Journal of Adhesion and Interface
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• v.22 no.4
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• pp.128-135
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• 2021

In this study, the acid polyols containing acid groups were synthesized, the novel polyurethane adhesive was developed by introducing the acid polyol by content. The acid polyols were introduced, the mechanical properties showed the maximum value when the acid content was 0.1 to 0.3 wt%, and it was confirmed that the mechanical properties and adhesive strength decreased at the content higher than 0.5 wt%. As the acid group, carboxylic acid and sulfuric acid were introduced to compare properties, and carboxylic acid showed stronger hydrogen bonding potential than sulfuric acid and improved mechanical properties. In addition, the correlation between particle size and mechanical properties was confirmed by introducing ZnO and CaCO₃. When ZnO and CaCO₃ were introduced, an ionic bond was formed with an acid group, and it was confirmed that mechanical properties were increased.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.4
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• pp.536-542
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• 2010

In this study, we determined the fat content, total fatty acid composition, trans fatty acid (tFA) content, and acid value of twenty samples of sweet-and-sour pork and fifteen samples of used frying oils collected from Chinese restaurants in Seoul. After the extraction of crude fat by the Folch method, the total fat content of the twenty sweet-and-sour porks ranged from 9.93 to 20.04%. The total unsaturated fatty acid content ranged from 50.05 to 81.22%, which mostly consisted of oleic and linoleic acid, while those of total saturated fatty acids were 18.06~49.26%. The tFA content of all of the twenty sweet-and-sour porks tested was less than 0.24 g per 100 g of food. The acid values of the fat extracted from the twenty sweet-and-sour porks ranged from 0.44 to 4.37. In the used frying oils, the ranges of the major compositional fatty acids were as follows: palmitic acid, 4.47~20.28%; oleic acid, 23.43~77.45%; linoleic acid, 5.6~53.06%; stearic acid, 1.81~7.38%. The tFA content in all of the fifteen used frying oils was less than 0.98 g per 100 g of fat, while the acid values of the fifteen used frying oils ranged from 0.27 to 2.41.

• Applied Biological Chemistry
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• v.44 no.1
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• pp.20-23
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• 2001

Several unusual fatty acids including myristic acid (14 : 0) and lauric acid (12 : 0) were investigated in the Iris family and other related plants. Especially the roots of Iris tecorum contained 75.9% myristic acid in total fatty acid contents and that of Iris germanica contained 57% myristic and 15.5% lauric acid (12 : 0) whereas 10.7% lauric acid and 9.5% capric acid (10 : 0) were detected in the roots of iris ensata as compared to the total fatty acid contents. The total fatty acid contents in the seeds of Foeniculi fructus and Torilis japonica was relatively higher 193.3 mg/g dry wt and 128.2 mg/g dry wt, respectively. 64.5% linoleic acid (18 : 2) and 48.9% ${\alpha}-linolenic$ acid (18 : 3) were observed in the seeds and leaves of iris tectorum whereas its lateral roots contained 9.5% caprylic acid (8 : 0) and 8.6% capric acid. The percentage of myristic acid of the total fatty acid in the immature seeds of iris tectorum and Iris germanica was 10.8% and 15.6%, respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.36-44
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• 1999

Samjangs which were prepared using magjang, traditional doenjang, and mixture of traditional doenjang and magjang were stored. Characteristics of the stored samjangs were investigated. Maximum titratable acidity was shown in traditional doenjang after 30 day of storage. Total sugar in samjangs decreased while reducing sugar increased to $11.45{\sim}12.35%$ from $8.44{\sim}9.29%$ after 40 days. Amino type nitrogen predominantly increased to $337.3{\sim}381.1\;mg%$ after 40 days from $48{\sim}53\;mg%$ of initial period of preparation. Among the free amino acids the content of glutamic acid $(202.6{\sim}464.6\;mg/100g)$ was highest and others were not too much changed. Forty two components including 7 alcohols, 4 esters, 13 acids, 6 aldehydes, 5 phenols, 3 pyrazines and others were found in samjangs. Ethanol, acetic acid ethyl ester and 2-phenylethanol were found in all treatments and ethanol, acetic acid ethyl ester, phenylacetaldehyde, butanoic acid, acetic acid, 3-methyl butanoic acid and 2,4-hexadienoic acid might be major volatile components considering of high peak area. 2-Phenylethanol, butandioic acid ethyl ester, butanoic acid and 2-methyl-2-butenoic acid were higher than other components in samjang with magjang while ethanol, acetic acid, 2,4-hexadienoic acid were in samjang with traditional doenjang and 3-methyl butanoic acid, acetic acid ethyl ester and methyl pentanoic acid were in the mixed treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.120-125
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• 2005

This study was carried out to investigate the changes in components of salted eggplant (chukyang) during storage. The contents of total and reducing sugar were decreased during storage, and the tendency was lower in the salted eggplants of vacuum packing storage than in the salted eggplants of rice bran immersion storage. The organic acids of salted eggplants were acetic acid, citric acid, lactic acid, and malic acid. And acetic and malic acid contents were much higher than the others. The content of acetic acid was increased during storage, but malic acid was decreased. Major amino acids of eggplants were valine, aspartic acid, glutamic acid, glycine, and alanine. The content of total amino acid was 1,488.18 mg/100 g in eggplant packed vacuum film at 20 days of storage, and higher than those in fresh eggplant. The content of total amino acid in eggplant immersed in wet rice bran was 745.42 mg/100 g at 20 days of storage, and decreased during storage. The contents of aspartic acid, alanine, cystine, and proline in free amino acids of salted eggplants were higher than other amino acids. The contents of phosphoserine, taurine, ${\gamma}$ -aminoisobutyric acid and hydroxyproline were higher than others. Posphoserine content was decreased during storage, but ${\gamma}$ -aminoisobutyric acid content was increased during storage.

• Journal of Animal Science and Technology
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• v.51 no.1
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• pp.15-24
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• 2009

Two experiments were conducted to compare the effects of different organic acids on growth performance and apparent nutrients digestibility in weaned pigs. In both the experiments, 180 pigs were assigned to four treatments with three replicates comprising of 15 pigs in each. Formic acid, ammonium-formate, lactic acid, and acid mixture were added to diets at 0.50% (Exp. 1) and 0.30% (Exp. 2) as dietary treatments for 5 and 6 wk feeding trial, respectively. The acid mixture was prepared by mixing formic acid and lactic acid at 50:50 ratios. To investigate the apparent ileal amino acids digestibility, twelve pigs (3 per treatment) were used and fitted with simple ileo-caecal T-cannula for both experiments. In Exp.1, growth performance was comparable (P>0.05) among pigs fed different organic acids, while acid mixture had higher (P<0.05) weight gain than that of lactic acid in Exp.2. The apparent ileal digestibility of amino acids was highest (P<0.05) in pigs fed acid mixture and lowest (P<0.05) in pigs fed formic acid diets in both experiments. These results indicated that supplementation with acid mixture (formic acid and lactic acid) improved performance and ileal amino acid digestibility in weaned pigs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.78-84
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• 1993

This study was conducted to investigate the effect of various polyethylene (PE) film packaging on the quality of strawberry during storage at low temperature. Gas composition in film was changed rapidly at early stage of storage and then kept at the level of 5~10% $CO_2$and 1~3% $O_2$. Weight loss and decay rate were low at 0.08mm PE film packed strawberries. Titratable acidity, pH and soluble solids were changed slightly during storage but its large difference according to film thickness was not observed. Decrease of flesh firm-ness and a value was restrained by PE film packaging. Free sugar of strawberry was composed of glucose and fructose in similar content and it was decreased a little during storage but the difference according to film thickness was not observed. The organic acids in strawberry were citric acid, malic acid, succinic acid, ascorbir acid, oxalic acid, tartaric acid and pyruvic acid and the major organic acid was citric acid. The contents of citric acid, malic acid, succinir acid and ascorbic acid were decreased and oxalic acid and tartaric arid were not changed during storage but pyruvic acid was increased in early stage and then decreased. These changes of organic acid were slight in packaged with 0.08mm PE film strawberry.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.226-232
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• 1985

Changes in lipid and fatty acid composition in Korean native Meju were investigated at one week interval over 6 weeks of fermentation. For the systematically, salicic acid column chromatography and gas liquid chromatography were used. Following results were obtained. 1. The lipid fraction obtained from the soared soybean and the cooked soybean were mainly composed of $72.47%{\sim}92.35%$ of neutral lipid, phospholipid and glycolipid were 4.64% and 4.88%, respectively. During fermentation period, lipid content decreased to 80.59%, but glycolipid and phospholipid contents increased. 2. The triglyceride contents of nonpolar lipids prepared from the cooked soybean and the soaked sobean was 89.66% and 87.83% respectively. Free fatty acid, diglyceride and sterol contents increased during fermentation, whereas triglyceride content decreased. 3. Lipids extracted from the soaked soybean and the cooked soybean were composed of 54.58% linoleic acid, $22{\sim}20%$ oleic acid, $10{\sim}12%$ palmitic acid and $3{\sim}5%$ stearic acid. 4. During the Korean native Meju fermentation in palmitic acid decreased from the second week and stearic acid through $3rd{\sim}4th$ week. Oleic acid and linoleic acid content decreased gradually, but linolenic acid content increased. 5. During the fermentation, myristic acid content of glycolipid fraction increased. Lipase activity reached to the maximum at the 3rd week.