• Title/Summary/Keyword: ${\alpha}$-amino Acid Esters

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Volatile Flavor Components in Cooked Black Rice (취반된 흑미의 휘발성 향기 성분)

  • Song, Seon-Joo;Lee, You-Seok;Rhee, Chong-Ouk
    • Korean Journal of Food Science and Technology
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    • v.32 no.5
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    • pp.1015-1021
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    • 2000
  • Volatile flavor components (VFCs) in cooked black rices (Suwon-415 and Chindo) were studied. The major reactions during cooking, which result in aroma volatiles, are the Maillard reaction between amino acids and reducing sugars, and thermal degradation of lipid. Black rices washed with water were soaked in 1.5 folds water and heated at $110^{\circ}C$ in oil bath for 30min. VFCs in cooked black rices were extracted for three hours by SDE and were analyzed by GC and GC/MS. A total of 91, 82 volatiles were identified in Suwon-415 and Chindo black rice, respectively. Suwon-415 was composed of 26 alcohols, 10 aldehydes, 5 acids, 11 esters, 15 ketones, 9 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 9 sulfur containing compounds. Chindo was composed of 28 alcohols, 9 aldehydes, 4 acids, 12 esters, 14 ketones, 5 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 4 sulfur containing compounds.

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Quality Characteristics for Doenjang Using Squid Internal Organs (오징어 내장을 첨가한 된장의 품질 특성)

  • Seo, Ji-Hyung;Jeong, Yong-Jin
    • Korean Journal of Food Science and Technology
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    • v.33 no.1
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    • pp.89-93
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    • 2001
  • The quality characteristics of doenjangs added with squid internal organs were evaluated. The contents of moisture, salt and amino type nitrogen were similar among traditional doenjang and squid doenjang(I, II, III). But the color values were different. pH and peroxide value(POV) were high in squid doenjangs. Squid doenjang(I, II, III) contained much taurine($53.26{\sim}170.90\;mg%$) and ${\alpha}-aminobutyric$ acid($35.17{\sim}151.00\;mg%$) which were not detected in traditional doenjang. Also aspartic acid and glutamic acid related to palatable taste, threonine, serine and proline related to sweet tastes were much more in squid doenjangs. Contents of isoleucine and leucine related to bitter taste were similar with traditional doenjangs. Comparing with traditional doenjang, volatile flavor components in squid doenjangs had high ratio of esters such as ethylbutylether and aldehydes such as 2-propanal, 3-methylbutanal in contrast with low alcohols. Especially ethylbutylether, 2-propanol, 3-methyl-1-butanal, 2,6,10,14-tetramethyl-pentadecane, ethyllinoleate were only in squid doenjangs. From the sensory evaluation after 4 weeks, squid doenjang(II) added with 10% squid internal organs obtained the highest scores for taste as differing from traditional soybean paste and squid doenjang(I). But the total acceptability was higher in traditional doenjang because of strong fishy smell and dark color in squid doenjang. After 8 weeks squid doenjang(I, II) obtained high scores for taste and low scores for color and flavor.

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Peptide Synthesis with Polymer Bound Active Ester III. The Effect of Spacer Arm in Peptide Synthesis with 1-Phenyl-3-methyl-4-oximino pyrazole Resin (고분자에 결합된 활성 에스테르에 의한 펩티드합성 III. 1-페닐-3-메틸-4-옥시미노피라졸레진을 이용한 펩티드 합성에서 Spacer Arm의 효과)

  • Wang, Young;Lee, Yoon-Sik
    • Applied Chemistry for Engineering
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    • v.4 no.1
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    • pp.132-143
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    • 1993
  • Aminomethyl polystyrene resins were prepared either from chloromethyl-resin(Merrifield resin) or from direct amidoalkylation of polystyrene resin. Two kinds of aminomethlyl resin were lengthened with spacer arms via sequential coupling of five ${\varepsilon}$-aminocaproic acids(ACA) respectively. In case of the resin prepared from the Merrifield resin, the amounts of free amino group of the resin were reduced by 25~30% after each coupling of ACA. But the one from direct amidoalkylation showed 3~5% loss after each coupling of ACA. 4-Nitroso-5-aminopyrazole resin was made by reacting ACA spacer arm resin, which was made from direct amidoalkylated resin, with 5-phenyl-7-methylpyrazole [4,3-c][1,2,4]oxadiazin-3-one. Several polymeric active esters of N-blocked amino acids were prepared from the 4-nitroso-5-aminopyrazole bound resins. In anchoring step of the amino acid derivatives on the resin, no substantial effect of bulkiness was found. 4-Nitroso-5-aminopyrazole bound active ester resins were found to be very reactive in N-acylation, The resulting peptides were obtained with 90~95% yield and characterized by NMR and other physical methods.

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Studies on the Chemical Constituents of the New Zealand Deer Velvet Antler Cervus elaphus var. scoticus-(I)

  • Lee, Nam Kyung;Shin, Hyun Jung;Kim, Wan Seok;Lee, Jong Tae;Park, Chae Kyu
    • Natural Product Sciences
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    • v.20 no.3
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    • pp.160-169
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    • 2014
  • 44 compounds and 9 minerals were isolated from and detected in the New Zealand deer velvet antler Cervus elaphus var. scoticus L$\ddot{o}$nnberg. The chemical structures of (1 - 26) were identified on the basis of the spectroscopic methods and comparisons with literature, respectively. The structures were identified as cholesterol (CS, 6), 7-keto-CS (7), $7{\beta}$-hydroxy-CS (8), and $7{\alpha}$-hydroxy-CS (9), and included 12 steroid $3{\beta}$-O-(palmitic/stearic/myristic acid esters; PM/SA/MS) [CS-$3{\beta}$-O-PM (1 - 1), CS-$3{\beta}$-O-SA (1 - 2), CS-$3{\beta}$-O-MR (1 - 3), 7-keto-CS-$3{\beta}$-O-PM (2 - 1), 7-keto-CS-$3{\beta}$-O-SA (2 - 2), 7-keto-CS-$3{\beta}$-O-MR (2 - 3), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-SA (3 -1), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-PM (3 - 2), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-MR (3 - 3), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-SA (4 - 1), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-PM (4 - 2), and $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-MR (4 - 3)], dinonyl phthalate (5), 8 nucleic acids analogues [uracil (10), deoxyguanosine (11), deoxyuridine (12), uridine (13), deoxyadenosine (14), adenosine (15), inosine (16), and guanosine (17)], and the 9 free amino acids [L-phenylalanine (18), L-isoleucine (19), L-leucine (20), L-tyrosine (21), L-valine (22), L-proline (23), L-threonine (24), L-alanine (25), and L-hydroxyproline (26)]. Also, there are 8 kinds of amino acids [asparagine, serine, glutamine, glycine, histidine, arginine, methionine, and lysine], 2 sialic acids [N-acetylneuraminic acid (27), ketodeoxynonulosonic acid (28)], and 9 minerals [Na > K > Ca > Mg > Fe > Zn > B > Al > Cu] were detected from the autoaminoacid analyzer and ICP spectrometer, HPAEC-PAD/HPLC-FLD, respectively. 9 kinds of oxycholesterol-$3{\beta}$-O-fatty acid ester (2 - 1, 2 - 2, 2 - 3, 3 - 1, 3 - 2, 3 - 3, 4 - 1, 4 - 2, and 4 - 3) and 3 nucleic acids (12, 14, and 15) were isolated from the velvet antler for the first time. 6 kinds of steroids (7, 8, 9, 2 - 1, 3 - 1, and 4 - 1) were examined for their anti-proliferative effects against L1210, P388D1, K562, MEG-01, KG-1, MOLT-4, A549, HepG2, MCF-7, SK-OV-3, and SW-620 cancer cell lines. They showed anti-proliferative effects with $IC_{50}$ values of 0.06, 2.16, 2.42, > 50.0, 1.66 and $8.31{\mu}M$ against L1210, while the values were 24.05, 9.44, 5.22, 0.25. 9.48 and $49.77{\mu}M$ against P388D1, respectively. The others were inactive.

Comparative analysis of volatile and non-volatile flavor compounds in rice paste made by α-amylase according to cultivars (α-amylase를 이용하여 제조한 쌀 페이스트의 품종에 따른 휘발성비휘발성 향미성분 비교분석)

  • Son, Eun Young;Kim, Hye Won;Kim, Sun Ah;Lee, Sang Mi;Paek, Se Hee;Kim, Sun Hee;Seo, Yong Ki;Park, Hye-Young;Oh, Sea-Kwan;Kim, Young-Suk
    • Journal of Applied Biological Chemistry
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    • v.60 no.3
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    • pp.283-291
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    • 2017
  • Rice that the half of population in the world eats as a staple food is mostly produced and consumed in Asia. However, its consumption is nowadays decreasing mainly due to diet diversity. Accordingly, some attempts are in demand to enhance the utilization of rice. In this study, profiling of volatile and non-volatile flavor components in rice pastes obtained by ${\alpha}$-amylase was performed and compared according to nine different rice cultivars domestically cultivated in Korea using gas chromatography-mass spectrometry combined by solid phase microextraction and gas chromatography-time of flight-mass spectrometry after a derivatization, respectively. In total, 46 volatile compounds identified included 6 alcohols, 6 aldehydes, 4 esters, 4 furan derivatives, 4 ketones, 1 acid, 1 sulfur-containing compound, 7 hydrocarbons, 5 aromatics and 8 terpenes. The non-volatile flavor components found were composed of 12 amino acids, 6 sugars and 4 sugar alcohols. In principal component analysis, rice paste samples could be discriminated according to cultivars on the score plots of volatile and non-volatile flavor compounds. In particular, some volatile compounds such as pentanal and 4,7-dimethylundecane could contribute to distinguish Senong 17 white and Senong 17 brown, whereas ethanol, 6-methylhep-5-en-2-one, and tridecane could be highly related to the discrimination of Iipum from other cultivars. Among non-volatile compounds, some amino acids such as glycine, serine and ${\gamma}$-aminobutyric acid and some sugars such as sucrose and fructose were mainly responsible for the discrimination of Danmi from the other cultivars. On the other hand, galactose, arabitol and mannose were more closely related to Senong 17 white than Senong 17 brown.