• Title/Summary/Keyword: TNBS-method

Search Result 5, Processing Time 0.073 seconds

Comparison of Determination Methods of Amino Nitrogen in Salt-Fermented Anchovy Sauce

  • Cho Young-Je;Kim Tae-Jin;Choi Yeung-Joon
    • Fisheries and Aquatic Sciences
    • /
    • v.4 no.3
    • /
    • pp.144-149
    • /
    • 2001
  • In other to establish the exact determination method of amino nitrogen (AN) in salt-fermented fish sauces, we determined the AN in fish sauces according to the measuring methods and also investigated the main factors influencing on determination method of AN. AN in salt-fermented anchovy sauce increased linearly as fermentation progressed, and was shown the highest amount measuring by the Formol method, followed by the trinitrobenzene sulfonic acid (TNBS) method and the Copper-salt method. AN concentration in anchovy sauces fermented for 12 months was $88.2\%$ and $77.6\%$ for the TNBS method and the Copper-salt method, respectively, on the basis of Formol method. The ratio of AN/total nitrogen (TN) in anchovy sauce fermented for 12 months was higher than that in commercial anchovy sauces. The determination of AN in anchovy sauce by the TNBS method was not affected by salt concentration, and slightly affected by heating. The effect of MSG on AN contents by Copper-salt method was shown higher than those by the Formol method and the TNBS method. The TNBS method was adaptable to measure the content of AN in fish sauce by this study.

  • PDF

Estimation of Amino-nitrogen Content in Salt-fermented Sand Lance Sauce (까나리액젓 중의 아미노태질소 측정)

  • Cho, Young-Je;Song, Min-Woo;Im, Yeong-Sun;Choi, Yeung-Joon
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.12 no.2
    • /
    • pp.213-223
    • /
    • 2000
  • In order to establish the exact determination method of amino nitrogen in fish sauces, we compared the amino-nitrogen content in salt-fermented sand lance sauces according to the measuring methods and investigated influencing factors on the procedure of measuring. Amino-nitrogen content was increased in both sand lance sauce during fermentation periods and commercial sand lance sauces. Amino-nitrogen in fermented sand lance sauces for 12 months occupied 88.7% and 75.2% for the trinitrobenzene sulfonic acid(TNBS) method and the Copper-salt method, compare to the Formol method. The ratio of amino-nitrogen/total nitrogen in fermented sand lance sauce for 12 months was higher than in commercial sand lance sauces. The determination of amino-nitrogen by the TNBS method was influenced by concentration of salt in sand lance sauce. The amino-nitrogen content was the highest in the Formol method and followed by the TNBS method and the Copper-salt method without the influence of heating time and monosodium glutamate(MSG) concentration. We concluded that the determination of amino nitrogen in fish sauces was correct to measure with the TNBS method.

  • PDF

Rapid Determination of Degree of Hydrolysis for Hemoglobin by Osmometry (Osmometry에 의한 Hemoglobin 가수분해도의 신속한 측정)

  • Chae, Hee-Jeong;In, Man-Jin;Kim, Dong-Ho;Kang, In-Kyu;Oh, Nam-Soon
    • Applied Biological Chemistry
    • /
    • v.44 no.3
    • /
    • pp.143-147
    • /
    • 2001
  • An osmometrical method for determination of the degree of hydrolysis (DH) of hemoglobin was comparatively examined through TNBS (trinitrobenzene) sulfonic acid) method using two experimental variables $({\alpha}\;and\;{\beta})$, which were chosen based on correlation curves between hydrolysis equivalents (h) and $leucine-NH_2$ equivalents. DH values measured through osmometry and TNBS method highly correlated with $R^2$ values of $0.974{\sim}0.991$, irrespective of the reaction pHs and types of enzyme used. $DH_{osm}/DH_{TNBS}$ was >$1.438{\sim}1.656$ depending on the hydrolysis pH $7.5{\sim}10.0)$. Correlation euqations were well fit for measuring DH of Hb hydrolysate at different pH conditions. $DH_{osm}/DH_{TNBS}$ for co-treatment system using Esperase and Flavourzyme was 1.658, in good agreement with that of 1.656 for the single enzyme (Esperase) system. Thus, the osmometrical method was suggested to be a convenient, reliable, and rapid method for determination of DH of hemoglobin hydrolysates.

  • PDF

Conditions of Quantitative Analysis for free Amino Acid in Fermented Proteins (발효단백질의 유리아미노산 정량)

  • Ryu, Hong-Soo;Moon, Jung-Hye;Lee, Kang-Ho
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.17 no.2
    • /
    • pp.136-143
    • /
    • 1988
  • This study was performed to provide the optimal conditions of quantitative analysis for free amino acid in fermented protein foods. The water extractable free amino acid from dairy fermented foods was extracted effectively at $75^{\circ}C$ for 40 min., while it were extracted from fermented soy products at $40^{\circ}C$ for 3 hours. A close results of free amino acid content to those from amino acid analyzer were obtained using OPDA method with lysine standard after deproteinizing with 1% picric acid. 95% ethanol used as a deproteinizing reagent could give a comparable results to those from picric acid treatment in determining free amino acid content using OPDA method. Therefore, ethanol treatment was more recommendable than picric acid treatment which has some troubles in removing excess picric acid through Dowex resin column. The most desirable precipitation method for free amino acid determination using TNBS method was 95% ethanol treatment among the various deproteinizing procedure. The copper salt method was not suitable owing to its lacking reproducibility and pronounced discrepancy in determining free amino acid.

  • PDF

Detection of Gelation in Ultra-high Temperature Treated Milks During Storage (초고온 멸균유의 저장중 겔 형성의 추적)

  • Park, In-Duck;Hong, Youn-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.25 no.4
    • /
    • pp.404-406
    • /
    • 1993
  • In order to detect the gelation of ultrahigh temperature (UHT) treated market milks during storage at 20+1C, the free amino groups were quantified with 2,4,6-trinitrobenzene sulfonic acid, and the measurement of pH values and the alcohol test were monthly carried out. The average tree amino groups were $0.94{\sim}1.11{\mu}M$ at 1 month, $1.95{\sim}2.17{\mu}M\;at\;5{\sim}6$ month and $4.95{\sim}6.36{\mu}M$ at 12 month. The pH values at the same time as above were $6.72,\;6.49{\sim}6.55\;and\;6.14{\sim}6.16$, respectively. The alcohol test showed positive results at $5{\sim}6$ month, which could indicate the casein instability and beginning of gelation. These results suggest that the gelation of UHT market milks could he predicted through checking some chemical parameters weekly and be helpful for quality control.

  • PDF