• 한국식품과학회지
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• 제25권5호
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• pp.552-557
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• 1993

대두 펩타이드의 아미노산 조성 및 평균소수도가 혈청 콜레스테롤의 농도에 미치는 영향을 조사하기 위하여, 대두 단백질(ISP), 카세인(CNP), 이들 단백질을 펩신으로 가수분해하여 pH에 다른 펩타이드 침전 획분들(SHT, SH8, SH6, SH4, CHT) 및 각 단백질과 같은 조성의 아미노산 혼합물(SAA, CAA)을 흰쥐에 섭취시키고 혈청콜레스테롤 농도를 측정하였다. 각 펩타이드의 아미노산 조성을 분석하고, 이로부터 구한 Lys/Arg 비율 및 소수성 아미노산의 몰분율은 혈청 콜레스테롤의 농도와 상관관계가 없었으며, Tanford, Manavalan 및 Meirovitch법으로 구한 평균소수도와도 상관관계가 없었다. 그러나, Krigbaum법으로 구한 평균소수도와는 상관계수가 -0.736으로 음의 상관관계이어서, 식이 펩타이드의 krigbaum 평균소수도가 높을 수록 래트의 혈청 콜레스테롤 농도가 낮아졌다.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1502-1510
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• 2018

Organic solvent-tolerant (OST) enzymes are widely applied in various industries for their activity and stability in organic solvents, for their higher substrate solubility, and for their greater stero-selectivity. However, the criteria for identifying OST enzymes largely remain undefined. In this study, we compared the amino acid composition of 19 OST esterases with that of 19 non OST esterases. OST esterases have increased the ratio of Ala and Arg residues and decreased the ratio of Asn, Ile, Tyr, Lys, and Phe residues. Based on our amino acid composition analysis, we cloned a carboxylesterase (EstSP2) from a psychrophilic bacterium, Sphingomonas glacialis PAMC 26605, and characterized its recombinant protein. EstSP2 is a substrate specific to p-nitrophenyl acetate and hydrolyzed aspirin, with optimal activity at $40^{\circ}C$; at $4^{\circ}C$, the activity is approximately 50% of its maximum. As expected, EstSP2 showed tolerance in up to 40% concentration of polar organic solvents, including dimethyl sulfoxide, methanol, and ethanol. The results of this study suggest that selecting OST esterases based on their amino acid composition could be a novel approach to identifying OST esterases produced from bacterial genomes.

• Preventive Nutrition and Food Science
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• 제3권4호
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• pp.368-373
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• 1998

Plasma amino acid concentration and Urinary exretion of free amino acids were measured in health female vegetarians(n=20, 19.9 $\pm$0.43 years old ) and age-mateched imnivores(n=20, 21.9$\pm$0.38years old) in Korean. differences infasting plasma amino acid concentrations and plasma aminogram pattern were not spectacular between the vegetarian and omnivore controls. Compared to the omnivores, vegetarians showed significantly lower plasma levels of methionine , phenylalanine, $\alpha$-aminobutyrate, citrulline, phosposerine and tarurine, and significantly higher plasma concentrations of arginine, $\alpha$-aminobutyrate, cirtrulline, phosphosierine and taurine, and significantly higher plasma concentrations of arginine, $\alpha$-aminoadipate, asparagine, aspartate, glutamate and ornithine. Although these differences were statistically significant, they were all within the normal range (21~70% differences )for human adults. Most of the urinary amino acids (nmol/mg creatinine or $\mu$mol/24 hr urine) were excreted to significantly lesser degree in vegetarians than was the case in omnivore controls. For almost every individual free amino acid, plasma concentration did not significantly correlate with urinary excretion level. These results indicate that vegetarians excreted less amino acids in their urine than did dominivores, most probably in an effort to maintain amino acid homeostasis to an altered dietary protein intake level and/or amino acid composition of their diets.

• Journal of Animal Science and Technology
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• 제59권12호
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• pp.28.1-28.8
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• 2017

Background: Major amino acids in pig diets are Lys, Met, Thr, and Trp, but little is known about the requirements for the other essential amino acids, especially on odorous compounds and microbial characteristics in feces of growing-finishing pigs. To this end, different levels of amino acid composition added to diets to investigate the effects of amino acid composition on microbial characteristics and odorous compounds concentration. Methods: A total eight (n = 8) barrows (Landrace ${\times}$ Yorkshire ${\times}$ Duroc) with an average bodyweight of $89.38{\pm}3.3kg$ were individually fed diets formulated by Korean Feeding Standards 2007 (old version) or 2012 (updated with ideal protein concept) in metabolism crates with two replication. After 15-day adaptation period, fresh faecal samples were collected directly from pigs every week for 4 weeks and analysed for total volatile fatty acids (VFA), phenols and indoles by using gas chromatography. The nitrogen was determined by Kjeldahl method. Bacterial communities were detected by using a 454 FLX titanium pyrosequencing system. Results: Level of VFA tended to be greater in 2012 than 2007 group. Among VFAs, 2012 group had greater (p < 0.05) level of short chain fatty acids (SCFA) than control.Concentration of odorous compounds in feces was also affected by amino acid composition in pig diet. Levels of ammonium and indoles tended to be higher in 2012 group when compared with 2007 group.Concentration of phenols, p-cresol, biochemical oxygen demand, and total Kjeldahl nitrogen, however, were lower (P < 0.05) in 2012 treatment group compare to 2007. The proportion of Firmicute phylum were decreased, while the Bacteriodetes phylum proportion increased and bacterial genera includingCoprococcus, Bacillus, and Bacteroides increased (p < 0.05) in 2012 compare to 2007 group. Conclusion: Results from our current study indicates that well balanced amino acid composition reduces odor by modulating the gut microbial community. Administration of pig diet formulated with the ideal protein concept may help improve gut fermentation as well as reduce the odor causing compounds in pig manure.

• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.411-415
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• 1990

The dabsylation of amino acids has been applied to resolve their optical isomers with the use of chiral mobile phase in high performance liquid chromatography. The dabsyl amino acids were successfully separated on reversed phase column($C_{18}$) by adding a chiral L-benzylproline-Cu(II) chelate to the mobile phase. The separation selectivity of the dabsyl amino acid enantiomers was not less than that of dansyl amino acids. The retention order of the dabsyl amino acid enantiomers was as those of the dansyl amino acid enantiomers except dabsyl threonine. The optical selectivity of the dabsyl amino acids increase with pH of the mobile phase and concentration of the chelate, but slightly decreases with concentration of buffer and organic solvent composition. However serine, methionine, valine, and leucine showed a slight decrease in the optical selectivity with increase in pH. The retention times of the dabsyl amino acids decreases with increasing pH and acetonitrile concentration but increases with the concentration of the chiral chelate added. The mechanism of the optical resolution is based on a stereospecific interaction including a intramolecular hydrophobic effect and SN-2 reactivity of the ligand exchange chromatography.It is advantageous to detect absorption at 436 nm, which is less interferent them the other detection systems. The derivatized dabsyl amino acids are stable for a month.

• 한국식품조리과학회지
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• 제6권1호
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• pp.33-40
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• 1990

As a series of investigation on the ex-N compounds, the amino acid composition of the naturally grown and cultured prawn meat extracts was analyzed according to the following extraction conditions: 70% ethyl alcohol extraction, alcohol treatment of the same concentration after hot water extraction for 30 min, and 5% TCA treatment. The Protein content and the level of pure protein was 22 .8% and 18.4% in naturally grown prawn muscle, and 21.8% and 15.3% in the cultured prawn muscle, respectively. None protein nitrogenous compounds of the extracts were 4.4% in the naturally grown prawn muscle and 6.5% in the cultured prawn muscle, respectively. According to the different extract condition, ex-N compounds and the amino acid composition and related compounds and the amino acid composition and related compounds showed high level from 5% trichloroacetic acid extraction. The content of ex-N compounds of the cultured prawn muscle was 1033.0mg%. whereas the content of amino acids and related compounds-N was 825.3mg%, nearly reached to 80% to the total extractive nitrogen. A common feature of the free amino acid composition in the extracts of the muscles of the naturally grown and cultured prawn was high contents of glycine, proline, taurine, alanine and hydroxyproline.

• 한국초지조사료학회지
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• 제42권3호
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• pp.183-187
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• 2022

Alfalfa is one of the most useful forage crops worldwide, containing a high level of amino acids that are essential to both human and animal health. However, amino acids and their concentrations may differ between plant parts. Hence, detecting amino acids in different plant parts would be useful in the development of diet supplements. The purpose of this study was to determine the amino acid content in alfalfa leaves, stems, and inflorescences using an amino acid analyzer. Asparagine and glutamic acid were the most abundant amino acids found in stems, leaves, and inflorescences than other amino acids. All parts of alfalfa had low concentrations of cysteine and methionine. All amino acids except asparagine were present in the highest concentration in leaves followed by inflorescences. Leaf had a rich amino acid content, namely asparagine, glutamic acid, leucine, proline, and lysine. However, the stem had a lower amino acid composition than the leaf or inflorescence. Overall, the data showed determining the amino acid content of forages provides a good approach to making animal feed with essential and specific amino acids and preventing excessive inclusion of amino acids.

• 한국식품영양학회지
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• 제18권1호
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• pp.63-71
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• 2005

인삼의 생산과정에서 부산물로 얻어지는 인삼엽을 건강 기능성 식품의 소재로 활용 가능성을 모색하기 위하여 인삼엽차를 건조법(DRT), 숙성법(AGT), 열처리법(HPT)등 3가지 방법으로 제조하고 화학적 조성의 변화를 조사하였다. 인삼엽차의 제조방법에 따른 일반성분 함량은 거의 유사하였으나 조지방, 환원당 함량은 HPT에서 감소되는 경향을 나타내었다. 유리당 함량은 DRT가 6.07%로 가장 많았으며 sucrose, fructose, glucose순이었다. 유리아미노산의 조성은 serine 이 309.6∼336.6 mg%로 가장 높았으며 valine, leucine, isoleucine, aspartic acid 순으로 그 함량이 높았고 DRT에 비하여 ACT, HPT에서 감소되는 추세를 나타내었다. 무기질 함량은 Ca 가 2,115 mg%로 가장 많았고 K, Mg, P, Na, Mn, Fe, Zn, Cu 순으로 제조방법 사이에 차이는 나타나지 않았으나 찻물의 무기질 함량을 좌우하는 침출율은 HPT가 가장 우수하였다. 특히 Zn, Mn, Mg등은 면역체계를 유지하며 체내 유해 활성산소의 제거에 관여하는 무기질로서 이들 함량이 높다는 점은 인삼엽차의 우수성의 하나로 평가된다. 인삼엽차의 총 비타민 C 함량은 HPT가 424.4 mg%로 가장 많았으며 침출율도 가장 높았다. 지방산 조성은 제조방법간 차이는 나타나지 않았으며 palmitic acid가 가장 높았고 linoleic acid, linolenic acid, oleic acid, stearic acid 순이었다. 한편 인삼엽차의 색도는 DRT에 비해 AGT, HPT 에서 L값이 감소하고 a값은 증가하여 갈색 물질의 증가를 나타내었다. 이상의 결과를 종합해볼 때 인삼엽차의 제조방법은 열처리법(HPT)에서 가장 우수한 품질을 나타낸 것으로 생각한다.

• 한국식품영양학회지
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• 제31권1호
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• pp.89-93
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• 2018

In this study, we investigated the nutritional composition including proximate, amino acid, vitamin, minerals, and the antioxidant activity of green tea (Camellia sinensis) pollen grains collected by Apis mellifera bees, for use as a health food. The crude protein and fat content was estimated at 26.14% and 3.49%, respectively. Eighteen amino acids were identified in green tea pollen, including 8 essential amino acids and 10 non-essential amino acids. The predominant amino acids were glutamic acid, proline and aspartic acid accounting for about 33.3% of total free amino acids. The concentration of vitamin C was the highest value of 35.7%, followed by $B_3$ and $B_2$ among the detected vitamins. The predominant minerals were potassium (790.32 mg/100g), followed by phosphorus (707.52 mg/100g) and sulfur (302.67 mg/100g), whereas copper, zinc and sodium were detected as minor elements. The antioxidant activity and phenolic content accounted for 33.8% at $500{\mu}g/mL$ extract and $2.55 {\mu}g/mg$, respectively.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.175-179
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• 1998

Some functional properties and nutritive value were determined for the protein concentrated fractionated from chrysanthemum flower in orer to renew interest in the flowers as food. Proximate components of chrysanthemum flower protein concentration (FPC) showed 61.2% protein, 2.0% fat and 35.2% carbhydrate on a dry basis. In amino acid composition of FPC, glutamic acid was the highest in the content, follwoed by aspartic acid, leucine and lysine. The ratio of essential/ total amino acids(E/T) was 0.42, showing a higher level of essential amino acids compared to the FAO reference protein. Digestibility of chrysanthemum FPC by pepsin and trypsin was lwoer than that of casein and was negatively correlative to both water and fat absorptions. Similar characteristics were determined between chrysanthemum FPC and milk casein in their emulsifying activity and emulsion stability. This results indicate that flowers or petals of chrysanthemum might be developed as a good source of protein.