Short Note: Nitrogen & Protein Determination in Salami & Sausage Using Kjeldahl

Protein determination is one of the key analyses performed in the food industry. The samples require digestion with sulfuric acid to convert nitrogen into ammonium sulphate. After conversion to ammonia through the alkalinization with sodium hydroxide, the sample is distilled into a boric acid receiver by steam distillation, followed by a titration with sulphuric acid solution. The nitrogen content is multiplied by a sample-specific factor to obtain the protein content. Please read the entire short note here.

BUCHI SpeedDigester K-436, K-439

BUCHI Kjeldahl Sampler System K-370/K-371  

Salami and Boiled Sausage Samples

Salami and Boiled Sausage Samples



Results: The glycine recoveries were 100.0 %, rsd 0.55 % (K-439) and 100.0 %, rsd 0.45 % (K-436). The determined protein contents are presented in the table below.




  Protein Content  K-439 [%] Protein Content K-436 [%]
Sausage  13.00 (0.52 %)  13.01 (0.90 %)
Salami  22.29 (0.49 %)  22.23 (0.28 %)


The determination of protein contents in salami and sausage according to Kjeldahl using SpeedDigester K-436, K-439, and Kjeldahl Sampler System K-370/K-371 provides reliable and reproducible results that correspond to the labelled values with low relative standard deviations. The total digestion time is approx. 90 min.