• Title/Summary/Keyword: acid values

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Studies on the Degradation of L-Tyrosine by Aspergillus oryzae (Aspergillus oryzae에 있어서 L-Tyrosine의 분해효소에 관한 연구)

  • Chung, Dong-Hyo;Park, Sung-Oh;Kim, Young-Jin
    • Applied Biological Chemistry
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    • v.14 no.2
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    • pp.131-135
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    • 1971
  • 1. L-Tyrosine-${\alpha}$-ketoglutaric transaminase and p-hydroxyphenylpyruvic acid oxidase are distributed in Aspergillus oryzae. 2. L-Tyrosine oxidation in extracts of acetone powder, cell free extract and culture liquid of Aspergillus oryzae cultivated in the shaking culture are considerably accelerated by the addition of ${\alpha}$-ketoglutaric acid and then formation of glutamic acid was identified by chromatography method. 3. The roles of ${\alpha}$-ketoglutaric acid and pyridoxal phosphate have been shown to be an amino group acceptor in a transamination reaction. 4. Enzyme systems of an extracts of acetone powder and cell free extract also rapidly oxidized L-tyrosine and p-hydroxyphenlpyruvic acid to homogentisic acid. 5. The optimum pH for L-tyrosine-${\alpha}$-ketoglutaric acid transaminase was pH values of 6.0 and 6.5, and that for p-hydroxyphenylpyruvic acid oxidase was at pH values of 7.5.

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Protein Hydrolysis with Formic Acid and Analysis of Amino Acid Using Butylthiocarbamyl - trimethylsilyl (BTC - TMS) Derivatives by Gas Chromatography

  • 우강융;이동선;김민철
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.3
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    • pp.320-324
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    • 2003
  • The protein hydrolysis with 6 M formic acid containing 0.3% tryptamine was a superior method for amino acid analysis of standard amino acid and protein than 6 M HCI containing 0.3% tryptamine. The recoveries of standard amino acid after acid hydrolysis were more accurate in the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially recovery of tryptophan showed higher values of 1.5 times than that of 6 M HCI hydrolysis. The results of analysis on the standard protein, bovine serum albumin, showed very similar values compared to the sequence analysis reported in the literature for the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially in the tryptophan recovery as standard amino acid recovery. Butylthiocarbamyl - trimethylsilyl (BTC - TMS) derivatives of 22 standard amino acids were successfully resolved DB-17 capillary column. Excellent reproducibility of standard amino acid recovery and composition of bovine serum albumin were obtained with BTC-TMS derivatives.

Changes in the Physicochemical Properties and Color Values of Salted and Fermented Shrimp (새우젓 발효 중 이화학적 특성 및 색도 변화)

  • Cho, Hee-Sook;Kim, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.1
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    • pp.69-76
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    • 2010
  • This study was performed to examine the effects of salt addition level on changes in the physicochemical properties and color values of salted shrimp during fermentation. Fresh shrimp were salted with different concentrations (8, 18, 28%) of Chunil salt and fermented at $20^{\circ}C$ for 160 days. In the 8% salted shrimp treatment, volatile basic nitrogen (VBN), amino nitrogen (AN), and trimethylamine (TMA) contents rapidly increased during the fermentation period, while in the 18 and 28% salt groups these increases were reduced throughout the 160 days of fermentation. Thiobarbituric acid (TBA) values increased rapidly for 120 days of fermentation and then decreased. The thiobarbituric acid values of the 18, and 28% salted and fermented shrimp groups were lower than the that of the 8% group. In addition, Hunter's color L, a, and b values decreased as the fermentation period increased.

Prediction of Digestible and Metabolizable Energy Content and Standardized Ileal Amino Acid Digestibility in Wheat Shorts and Red Dog for Growing Pigs

  • Huang, Q.;Piao, X.S.;Ren, P.;Li, D.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.12
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    • pp.1748-1758
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    • 2012
  • Two experiments were conducted to evaluate the effects of chemical composition of wheat shorts and red dog on energy and amino acid digestibility in growing pigs and to establish prediction models to estimate their digestible (DE) and metabolizable (ME) energy content and as well as their standardized ileal digestible (SID) amino acid content. For Exp. 1, sixteen diets were fed to thirty-two growing pigs according to a completely randomized design during three successive periods. The basal diet was based on corn and soybean meal while the other fifteen diets contained 28.8% wheat shorts (N = 7) or red dog (N = 8), added at the expense of corn and soybean meal. Over the three periods, each diet was fed to six pigs with each diet being fed to two pigs during each period. The apparent total tract digestibility (ATTD) of energy in wheat shorts and red dog averaged 75.1 and 87.9%. The DE values of wheat shorts and red dog averaged 13.8 MJ/kg (range 13.1 to 15.0 MJ/kg) and 15.1 MJ/kg (range 13.3 to 16.6 MJ/kg) of dry matter, respectively. For Exp. 2, twelve growing pigs were allotted to two $6{\times}6$ Latin Square Designs with six periods. Ten of the diets were formulated based on 60% wheat shorts or red dog and the remaining two diets were nitrogen-free diets based on cornstarch and sucrose. Chromic oxide (0.3%) was used as an indigestible marker in all diets. There were no differences (p>0.05) in SID values for the amino acids in wheat shorts and red dog except for lysine and methionine. Apparent ileal digestibility (AID) and SID values for lysine in different sources of wheat shorts or red dog, which averaged 78.1 and 87.8%, showed more variation than either methionine or tryptophan. A stepwise regression was performed to establish DE, ME and amino acid digestibility prediction models. Data indicated that fiber content and amino acid concentrations were good indicators to predict energy values and amino acid digestibility, respectively. The present study confirms the large variation in the energy content and amino acid digestibility in wheat shorts and red dog, and describes the factors that influence this variation and presents equations based on chemical composition that could probably be used to predict the DE and ME values as well as the amino acid digestibility of wheat shorts and red dog.

The Quality Characteristics of Sulgidduk Prepared with Green Tea or Rosemary Powder (녹차 및 로즈마리 가루를 첨가한 설기떡의 품질특성)

  • Gwon, So-Young;Moon, Bo-Kyung
    • Korean journal of food and cookery science
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    • v.25 no.2
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    • pp.150-159
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    • 2009
  • The purpose of this research was to improve the quality of Sulgidduk by additions of green tea or rosemary powder to enhance its functional properties and antimicrobial effects. The green tea or rosemary powders were added to the Sulgidduk at different levels (1 or 3%), and color values, textural characteristics, sensory qualities, pH values, and acetic acid values were evaluated. With higher amounts of green tea or rosemary powder, the L-values of samples decreased and a-and b-values increased. Texture profile analyses indicated that hardness was significantly different among all the samples. The sensory evaluation results showed that the 1% addition of green tea or rosemary powder did not cause significant differences in overall acceptability, flavor, or taste. During storage, pH values decreased in all groups and the control group showed the lowest value. Acetic acid values increased during storage and the control group showed the highest value in the last stage of storage. Finally, the L- and a-values of samples did not change significantly during storage.

A Study on the Antioxidative Effect and Quality Characteristics of Cookies Made with Lycii fructus Powder (구기자를 첨가한 쿠키의 품질특성과 항산화효과)

  • Park Bock-Hee;Cho Hee-Sook;Park Sun-Young
    • Korean journal of food and cookery science
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    • v.21 no.1 s.85
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    • pp.94-102
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    • 2005
  • The purpose of this study was to investigate the antioxidative effect and quality characteristics of cookies made with Lycii fructus powder(LFP). The cookies were stored at $50^{\circ}C$ for 40 days. The LFP additive increased the moisture, ash, crude protein and volume of the cookies. When LFP was added at $5\%$ into the cookies, the spread ratio was higher than for the control, the $10\%$ and the $20\%$ LFP cookies. As more LFP was added, the L-value decreased, and the a--values and b-values increased for the color values. For the textural characteristics, springiness and cohesiveness of the control cookies were the highest among the samples, the other side, brittleness and gumminess were higher in cookies made with LFP than in the control cookies. Overall, the cookies made with $5\%$ LFP were preferred more than the other cookies, as tested forby sensory evaluation. The cookies made with LFP contained mostly palmitic acid (C16:0) followed by oleic acid (C18: 1) and stearic acid (C18:0). The acid value, peroxide value, and thiobarbituric acid value were lower in cookies made with $5\%$ and $10\%$ LFP than in those cookies made with $20\%$ LFP and the control cookies.

The Effect of Salt Concentrations on the Production of Volatile Organic Acids by Zygosaccharomyces rouxii, a Soy Sauce Yeast (간장에서 분리한 Zygosaccharomyces rouxii의 휘발성 유기산 생성에 미치는 식염농도의 영향)

  • 권동진;하덕모
    • Microbiology and Biotechnology Letters
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    • v.22 no.2
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    • pp.120-125
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    • 1994
  • By using a synthetic medium simulated on the amino acid composition of soybeam, the effect of salt concentrations on the production of volatile organic acid by the strains of Zygosaccharomyces rouxii So-3101, a soy sauce yeast, was studied at the concentrations of 12.5, 18.0, 22.0 and 28.5% NaCl. The growth, consumption of glucose, and production of alcohol, total acid and volatile organic acid, showed the highest values at a concentration of 12.5% NaCl, and those values were decreased with an increase in the salt concentration. The ratio of volatile organic acid to total organic acid was remained at approximately the same level within the range of salt concentrations between 12.5~22.0%, whereas the ratio was decreased at a salt concentration of 28.5%. After incubation for 16 days, 8 volatile organic acids, i.e. acetic, propionic, n-butyric, isobutyric, isovaleric, isocaproic, n-caproic, and heptanoic acids, were detected by gas chromatography. Among the volatile organic acids, acetic acid was produced in the appreciable amiunt and its ratio to the other volatile acids was increased with an increase in the salt concentration.A small amount of isocaproic, propionic, isobutyric and isovaleric acids were produced, and n-caproic, n-butyric and heptanoic acids were detected only at the lower salt concentration.

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Determination of Organic Acids in Tobacco Leaves by HPLC (HPLC를 이용한 잎담배 중 유기산 함량 분석)

  • Min, Hye-Jeong;Jang, Seok-Su;Kim, Ick-Joong;Shin, Jun-Won;Kim, Yong-Ha;Min, Young-Keun
    • Journal of the Korean Society of Tobacco Science
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    • v.28 no.2
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    • pp.130-135
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    • 2006
  • This study was carried out to improve the analytical methods for determination of organic acids in tobacco leaf by HPLC. The samples for HPLC analysis were pre-treated by means of SPE. The calibration curve for each acid was linear and $R^2$ values ranged from 0.9990 to 1.0000. The limit of detection were obtained from the calibration curves and their values were between 1.39 to $4.87{\mu}g/mL$. Recovery rates of organic acids were between 88.6 % to 98.5 %. The concentrations of organic acids among the various tobacco leaves were compared to the concentration of organic acids, were in the order oriental, burley, flue-cured tobacco. In the case of flue-cured and oriental tobacco leaves, the order of concentration of organic acids was malic acid, oxalic acid, citric acid. But in the case of burley tobacco leaves, the order of concentration of organic acids was citric acid, oxalic acid, malic acid.

Effect of addition of lactic acid bacteria on quality of rye silage harvested at early heading stage

  • Kuppusamy, Palaniselvam;Choi, Ki-Choon;Srigopalram, Srisesharam;Ilavenil, Soundharrajan;Park, Hyung-Su;Jung, Jeong Sung
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.285-285
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    • 2017
  • This study is aimed to analyze the effect of lactic acid bacteria inoculants (LAB) on quality of rye silage fermentation, harvested at early heading stage. The nutritive values were similar between the control and LAB inoculated silages. The pH of rye silage in LAB inoculation significantly decreased as compared to control (p<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (p<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (p<0.05). Therefore, we suggest that rye silage could be improved by novel lactic acid inoculation.

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The Measurement and Estimation of Lower Flash Point for 2-Propanol+Acid Systems Using Cleveland Open Cup Apparatus (클리브랜드 개방식 장치를 이용한 2-propanol+acid류 계의 하부 인화점 측정 및 예측)

  • Ha, Dong-Myeong;Lee, Sung-Jin
    • Fire Science and Engineering
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    • v.21 no.4
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    • pp.32-37
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    • 2007
  • An accurate knowledge of the flash point is important in developing appropriate preventive and control measures in industrial fire protection. The lower flash points for the 2-propanol+acetic acid and 2-propanol+-n-propionic acid systems were measured by Cleveland open cup apparatus. The experimental data were compared with the values calculated by the Raoult's law, the Wilson equation and the NRTL(non random two liquids) equation. The calculated values based on the Wilson and NRTL equations were found to be better than those based on the Raoult's law. And the predictive curve of the flash point prediction model, based on NRTL equation described the experimentally-derived data were more effective than the case of the Wilson equation.