GB 5009.235-2016 Translated English of Chinese Standard. GB5009.235-2016: National Food Safety Standard - Determination of Amino Acid Nitrogen in Foods
https://www.chinesestandard.net, 11 mai 2019 - 10 pages
This Standard specifies the method for determination of amino acid nitrogen in soy sauce, grain paste and soybean paste. Method 1 of this Standard applies to the determination of amino acid nitrogen in soy sauce which is brewed or prepared from grain and its by-products such as bean cake and bran, sauce which is made from grain, AND soybean paste products which are made from soybean and wheat flour. Method 2 applies to the determination of amino acid nitrogen in soy sauce which is brewed or prepared from grain and its by-products such as bean cake and bran.
100 mL volumetric accurately acetate-acetic acid buffer acetylacetone add water amino acid nitrogen amount bottle calculate calculate the total color developer Compare concentration consumed cooled determination of amino dilute to 100 ethanol follows formaldehyde solution further titrate grain paste grams g hydroxide standard solution hydroxide standard titration magnetic stirrer mass measure the absorbance Method for analysis milliliters mL milliliters of sodium mL of formaldehyde mL of sodium mL of water mL volumetric flask number of milliliters pH meter indicates pH reaches 9.2 potassium hydrogen phthalate Preparation reagent blank test record the number reference potassium hydrogen result room temperature sample diluent sauce scale shake sodium acetate-acetic acid sodium hydroxide solution sodium hydroxide standard solution 1 mol/L solution to titrate standard curve standard solution c(NaOH standard titration solution titration solution c(NaOH transfer volume of sodium wash water bath water to dilute water to dissolve wavelength of 400 Weigh 5.0 g