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, May 11, 2019 - Health & Fitness - 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 acetate-acetic acid buffer Acetic acid acetylacetone add water added with formaldehyde amino acid nitrogen Ammonia-nitrogen standard stock analysis of hygienic brewed or prepared color developer consumed determination of amino dilute to 100 ethanol Evenly stir formaldehyde solution grain paste grams g hydroxide standard solution hydroxide standard titration linear regression magnetic stirrer measure the absorbance milliliters mL mL of ammonia-nitrogen mL of formaldehyde mL of sodium mL of water mL volumetric flask number of milliliters pH meter indicates Pipette potassium hydrogen phthalate reagent blank test record the number reference potassium hydrogen refrigerator below 10°C sample dilution solution sauce sodium acetate-acetic acid sodium hydroxide solution sodium hydroxide standard solution 1 mol/L solution pH 4.8 solution to titrate soy sauce specified by GB/T standard curve standard solution c(NaOH standard titration solution stock solution 1.0 titration solution c(NaOH volume of sodium water bath water to dilute water to dissolve wavelength of 400