Protein is part of almost all foodstuffs and animal feed. The protein content is calculated with the protein factor (depending on the sample type) from the determined nitrogen content of a sample and is a decisive criteria for the quality and price of a product. Furthermore, it is part of the compulsory information on foodstuffs along with carbohydrates, sugar, fat, dietary fibre and sodium. As a result, this analysis is of great importance for the feed and food industry.
After an analytical examination, the products are labelled with corresponding nutritional information for the information of the consumer. This declaration is made obligatory for producers in national and transnational laws.
Since the protein content is calculated on the basis of the nitrogen content, the same methods are used for analysis as for nitrogen determination: Kjeldahl, Dumas and NIR.