This method describes how to determine the total nitrogen in malt.
Malt intended for use in beer brewing or elsewhere in the food industry.
The determination of nitrogen content according to Kjeldahl is divided into the following steps:
a. Digestion of the sample (oxidation of substances H2O, CO2, NH3)
b. Distillation (distillation of NH3 over into a boric acid solution)
c. Titration (determination of the amount of NH3 present in the receiver after distillation)
a. Digestion → 2 NH3 + H2SO4 → (NH4)2SO4
b. (NH4)2SO4 + 2 NaOH → Na2SO4 + 2 NH3 + 2 H2O
3 NH3 + H3BO3 → (NH4)3BO3
c. 2 (NH4)3BO3 + 3 H2SO4 → 3 (NH4)2SO4 + 2 H3BO3