• 한국환경과학회지
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• 제17권2호
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• pp.211-224
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• 2008

Characteristics of the esterification reaction between free fatty acid in rice bran oil and methanol was investigated in the presence of catalysts, such as PTS(p-toluene sulfonic acid), Amberlyst 15 dry and SCX(silica gel based strong cation exchange resin). While reaction temperature was kept constant at $65^{\circ}C$, initial feed content of free fatty acid was varied from 100% to 1% by addition of pure free fatty acid which was previously made from rice bran oil. Also, the effect of mole ratio of methanol to fatty acid on the final conversion was examined. When esterification of pure free fatty acid was catalyzed by several acids, final conversions were increased in order of Amberlyst 15 dry, SCX and PTS. Using PTS catalyst, initially the reaction proceeded in homogeneous 2nd oder reaction mechanism. However, phase of reaction mixture changed from homogeneous to heterogeneous along the reaction time and then reaction rate was retarded by mass transfer resistance of methanol. Final conversion of free fatty acid in reaction mixture was depended on initial feed content of free fatty acid, and had maximum value at 30% of initial feed free fatty acid content for all kinds of catalysts used. And the final conversion was increased with mole ratio of methanol by the improvement of reaction rate. When initial feed free fatty acid content below 10% and the reaction was catalyzed by PTS, concentration of free fatty acid in reaction mixture was increased in the middle of reaction time by hydrolysis of triglyceride in reaction mixture. Also, if silica gel was added into the reaction mixture which had initial feed free fatty acid content below 50%, final conversion was increased by the adsorption of moisture produced. The SCX catalyst made the esterification reaction of free fatty acid to progress like in case of PTS catalyst. However, when initial feed free fatty acid content below 10%, concentration of free fatty acid in. reaction mixture was decreased monotonically and not increased in the middle of reaction time on the contrary to the case of PTS. Thus, SCX catalyst accomplished more high value of final conversion than PTS catalyst for the initial feed fatty acid content range from 50% to 5% In case of initial feed free fatty acid content of 1% and mole ratio of methanol was 2, concentration of free fatty acid in reaction mixture increased over the initial feed free fatty acid content for all kind of catalysts used. Although SCX catalyst was added into reaction mixture which had 1% of initial feed fatty acid content, final conversion was hardly raised by mole ratio of methanol.

• Journal of Microbiology
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• 제42권2호
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• pp.133-138
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• 2004

This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bac-teria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree val-ues than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.

• 한국식품영양학회지
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• 제37권2호
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• pp.123-127
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• 2024

The fatty acid composition and free amino acid content of domestic soybean cultivars were analyzed to confirm the quality characteristics of protein and fat contained in soybeans. The saturated fatty acid content of soybeans included palmitic acid at 9.47~11.15%, followed by stearic acid and myristic acid. The total saturated fatty acid content in soybeans was 12.56~14.34%, with Taekwang having the lowest content, followed by Daewon, Seonyu, Cheonga, and Jinpung. The linoleic acid content, an unsaturated fatty acid, was 45.69~58.17%, with Taekwang showing the lowest composition and Jinpung showing the highest composition. Next was oleic acid at 14.69~33.86%. Jinpung had the highest linoleic acid composition, had the lowest and Taekwang which had the least linoleic acid, had the highest. The unsaturated fatty acid content was in the order of linolenic acid, eicosatrienoic acid, eicosadienoic acid, and eicosapentaenoic acid. The total free amino acid content was 217.28~456.66 mg%, with Daewon showing the highest free amino acid content, followed by Seonyu, Taekwang, Cheonga, and Jinpung. The free amino acid content varied depending on the cultivars, but in general, the free amino acids in the soybeans used in the experiment showed higher aspartic acid, glutamic acid, and proline contents than other amino acids.

• Natural Product Sciences
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• 제1권1호
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• pp.5-9
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• 1995

The metabolites of marine mollusk Mytilus edulis were isolated and characterized, revealing the presence of the rare free fatty acids and proteinogenic amino acids together with a non-proteinogenic free amino acid, taurine. The free fatty acids in this organism were particularly interesting for the presence of both unusual n-6 acid [20:4 (n-6)] and triple bond containing acid (2,5-octadecadiynoic acid). In addition to the proteinogenic amino acids commonly found in proteins, non-proteinogenic free amino acid taurine was isolated and the structure was determined by its physicochemical properties. Recently taurine has been given much interest in the molecular level because of diverse biological activities and the medicinal properties. Furthermore, the result of the analyses of analyses of free amino acids showed that glycine, glutamic acid, serine and alanine, which were considered to be related to the taste of this organism, are predominantly present.

• 한국식품영양과학회지
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• 제6권1호
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• pp.17-20
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• 1977

A. altissima 엽(葉)의 free amino acid 및 free organic acid의 함량(含量)을 측정한 결과는 다음과 같다. 1. free amino acid는 lysine, histidine, arginine, tryptophan, aspartic acid, glutamic acid, threonine, isoleucine, leucine, tyrosine, phenylalanine 등 17종(種)이 정량(定量)되었으며 이들 중 glutamic acid가 가장 많아 전(全)아미노산량의 48.3%를 차지하였다. 2. free organic acid는 formic acid, acetic acid, oxalic acid, maleic acid, succinic acid, fumaric acid, citric acid, tartaric acid 등 8종(種)이 정량되었고 sorbic acid는 미량(微量)이었으며, 이들 중 fumaric acid가 가장 많았다.

• 대한약리학회지
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• 제30권2호
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• pp.255-260
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• 1994

There are some reports about the influences of free fatty acids on the albumin binding of drugs. But they were concerned to the limited free fatty acids, mostly of azapropazone-warfarin bidning site bound drugs and determination of dissociation and association constants by stopped flow technique. These data were not enough to make conculsions for the general tendency of free fatty acid to albumin binding. Therefore the influence of various saturated fatty acids of $C_{10{\sim}20}$, oleic acid and linoleic acid as unsaturated fatty acids to albumin binding of warfarin and dansylsarcosine were studied by equilibrium dialysis. The concentration of free drug was determined by spectrophotometer according to the molar ratios of 0, 0.5, 1, 2 and 4 between free fatty acid and albumin. There were significant increasing in the free durg concentration of warfarin and dansylsarcosine when the molar ratio for capric acid, lauric acid and palmitic acid was 4. The free warfarin concentration was increased significantly at a molar ratio of 4 between oleic acid and albumin. Therefore the albumin binding of durgs can be variated significantly by increased free fatty acid of diabetics and cause to the pharmacokinetic variation between healthy and diabetics.

• 한국식품조리과학회지
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• 제14권3호
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• pp.250-254
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• 1998

A variation of free sugar and amino acid contents of pears during the ripening period was determined by HPLC and amino acid analyzer. The research results are as follws: Fructose, glucose and sucrose were present in the pears. The contents of fructose was the highest, followed by glucose and sucrose in order. The contents of total sugar in Shingo and Youngsan was similar, but the contents of frucose in Shingo was lower and the contents of sucrose was higher than that of Youngsan (p＜.001). During the ripening period, the contents of fructose and glucose gradually increased during the harvesting season and then somewhat decreased. The contents of sucrose increased continually, while the contents of total free sugar reached the maximum during the harvesting season, it was 10.41%, 10.29% in Shingo and Youngsan and then decreased gradually. The contents of total free amino acid in Shingo was higher than that of Youngsan. A variation ratio and the composition of amino acid in Shingo and Youngsan during the ripening period didn＇t make a significant difference. The major free amino acid of the pears was in the order of aspartic acid, serine, threonine, histidine, glutamic acid, valine, arginine, and alanine. During the ripening period, aspartic acid, threonin, serine, methionine, isoleucine, leucine, histidine, and Iysine increased gradually. Glutamic acid, alanine, valine, arginine didn＇t show much change. The contents of total free amino acid increased during the ripening period.

• Applied Biological Chemistry
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• 제29권4호
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• pp.346-351
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• 1986

이조대맥의 맥아제조시 유리 및 결합지질과 중성지질의 함량변화와 구성지방산의 변화를 조사하였다. 1. 이조대맥의 지질함량 27.9mg/g-d.w.중 유리지질과 결합지질이 각각 22.6, 5.3mg/g-d.w.으로서 유리지질이 대부분을 차지하였으며, 맥아제조시 발아일수가 경과함에 따라 다 같이 감소하였다. 2. 이조대맥의 중성지질의 함량은 21.0mg/g-d.w.으로서 전지질의 75% 정도 차지하였으며, 맥아제조시 발아일수가 경과함에 따라 감소하였다. 3. 이조대맥의 주지질인 중성지질의 조성은 triglyceride가 54.6%로 대부분을 차지하였으며, 다음으로 free fatty acid, free sterol, 1,2-diglyceride, 1,3-diglyceride순이었고, 이들 중 triglyceride는 발아기간중 감소하였으며, free fatty acid와 sterol ester는 증가하였다. 4. 유리지질 및 결합지질의 구성지방산은 다같이 linoleic acid가 50% 이상을 차지하였으며, 다음으로 palmitic acid, oleic acid 등이 주지방산이었다. 그리고 주지방산인 linoleic acid는 발아기간 중 증강이 뚜렷하지 않았으나 palmitic acid는 유리지질에서 증가하는 반면에 결합지질에서는 감소하였고, oleic acid는 유리지질에서 감소하는 반면 결합지질에서 변화하지 않아 뚜렷한 차이를 나타내었다. 5. 중성지질의 구성지방산 조성은 유리지질과 결합지질은 다같이 linoleic acid가 주지방산이었고 다음으로 palmitic acid, oleic acid순이었다. 발아과정중의 구성지방산의 변화는 palmitic acid가 증가하는데 비하여 주지방산인 linoleic acid나 stearic acid가 다소 감소하는 경향이었다.

• 동아시아식생활학회지
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• 제4권3호
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• pp.103-109
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• 1994

Changes in taste components of Backilju, an traditional alcoholic beverage of Korea, were investigated. Ethanol(17%) was the most abundant, and then isoamylalcohol(23mg%) and methanol(8mg%) were also detected in a small amount in Backilju. Major non-volatile organic acids were lactic and malic acid, followed by citric, fumaric and succinic acid. Arginine, phenylalanine and glutamic acid were major free amino acids and essential amino acid content was 230∼560 mg%, which was 45∼48% of total free amino acids. The major fatty acid of total lipid was palmitic acid(37∼43%). It has been found that the Backilju contained more free amino acids and alcohols than other Korean Yokjus.

• 한국식품영양과학회지
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• 제1권1호
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• pp.37-50
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• 1972

An analysis of the free amino acid contained in the plasma and erythrocytes of the six groups of Wistar Strain male adult rats(body weight 200-300g) having fasted for sixteen hours was made by means of the HITACHI Amino Acid Autoanalyzer and the result of which was corrected with RC-24 B TOMY Micro Hematocrit Centrifuge. There was a depression of the plasma and erythrocytes free amino acid level on the noprotein diet with ad libitum feeding. But on the 20% casein diet there was an elevation in the levels of free amino acid and consequently alanine, glysine, lysine, serine and arginine level in the erythrocytes and threonine glutamic acid and taurine level in the plasma increased on the high protein diet. There was more plasma and erythrocytes free amino acid level on the 5% casein-30% fat diet than on the 5% casein-no fat diet with pair-feeding. In comparison, on the low calorie diet more free amino acids were found in plasma than in erythrocytes, but on the higher calorie diet more free amino acids were found in the erythrocytes than in the plasma. On the 20% casein-30% fat diet with pair-feeding the erythrocytes free amino acids level increased but in plasma free amino acids level decreased. Such as an opposite result was given in plasma and erythrocytes free amino acids level. In the pair-fed four groups, erythrocytes per plasma generally increased in the rate of less than 10.0 as the calorie increased. The essential amino acid per non essential amino acid generally increased in the ratio as protein level and calorie increased, and that ratio range was from 0.2 to 0.7. And essential amino acid per non essential amino acid of plasma was higher than that of erythrocytes.