prEN 18198
(Main)Algae and algae products — Nitrogen content measurement and protein content calculation for micro- and microalgae
Algae and algae products — Nitrogen content measurement and protein content calculation for micro- and microalgae
This document describes a method for determining the total protein content of algal biomass.
Therefore, an existing method for measurement and calculation will be adapted.
The method consists of the measurement of the nitrogen content by a practical test method and the calculation of the protein content by a coefficient.
The document will describe the test method for nitrogen measurement.
As the coefficient usually used for protein determination (6.25) is too high for algae, the document will give a recommendation for a coefficient which is more specific to algae and thereby more accurate.
Algen und Algenprodukte - Messung des Stickstoffgehaltes und Berechnung des Proteingehaltes von Mikro- und Makroalgen
Algues et produits à base d'algues — Mesure de la teneur en azote et calcul de la teneur en protéines des micro et macroalgues
Alge in izdelki iz alg - Merjenje vsebnosti dušika in izračun vsebnosti beljakovin v mikro- in mikroalgah
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2025
Alge in izdelki iz alg - Merjenje vsebnosti dušika in izračun vsebnosti beljakovin v
mikro- in mikroalgah
Algae and algae products - Nitrogen content measurement and protein content
calculation for micro- and microalgae
Algen und Algenprodukte - Messung des Stickstoffgehaltes und Berechnung des
Proteingehaltes von Mikro- und Makroalgen
Algues et produits à base d'algues - Mesure de la teneur en azote et calcul de la teneur
en protéines des micro et macroalgues
Ta slovenski standard je istoveten z: prEN 18198
ICS:
13.020.55 Biološki izdelki Biobased products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2025
ICS
English Version
Algae and algae products - Nitrogen content measurement
and protein content calculation for micro- and microalgae
Algues et produits à base d'algues - Mesure de la Algen und Algenprodukte - Messung des
teneur en azote et calcul de la teneur en protéines des Stickstoffgehaltes und Berechnung des Proteingehaltes
micro et macroalgues von Mikro- und Makroalgen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 454.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 18198:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General . 7
5 Kjeldahl nitrogen content . 7
5.1 Principle . 7
5.2 Reagents and materials . 7
5.3 Apparatus . 8
5.4 Sampling . 8
5.5 Preparation of test sample . 8
5.6 Procedure. 9
5.6.1 General . 9
5.6.2 5Test portion . 9
5.7 Determination . 9
5.7.1 Digestion of organic matter . 9
5.7.2 Distillation of ammonia . 9
5.7.3 Titration . 10
5.8 Blank test . 10
5.9 Check test . 10
5.10 Calculation of nitrogen content and expression of results . 11
5.10.1 Distillate collected in sulfuric acid. 11
5.10.2 Distillate collected in boric acid . 11
5.11 Precision . 11
5.11.1 Interlaboratory test . 11
5.11.2 Repeatability . 11
5.11.3 Reproducibility . 12
5.12 Test report . 12
6 Dumas total nitrogen content . 12
6.1 Principle . 12
6.2 Reagents . 13
6.3 Apparatus . 14
6.4 Sampling . 14
6.5 Preparation of test sample . 14
6.6 Procedure. 14
6.6.1 General . 14
6.6.2 Test portion . 14
6.6.3 Control of oxygen supply . 15
6.6.4 Calibration . 15
6.6.5 Determination . 15
6.6.6 Detection and data processing . 15
6.7 Calculation of total nitrogen content . 16
7 Precision . 16
7.1 Interlaboratory tests . 16
7.2 Repeatability . 16
7.3 Reproducibility . 16
8 Test report . 16
9 Difference between Kjeldahl and Dumas methods . 17
10 Calculation of the crude protein content . 17
11 Calculation of specific nitrogen-to-protein conversion factors . 18
Annex A (informative) Details on Interlaboratory study on two algae samples testing of
nitrogen content by Kjeldahl method and by Dumas method . 19
Annex B (informative) Examples of protein calculations . 22
Bibliography . 24
European foreword
This document (prEN 18198:2025) has been prepared by Technical Committee CEN/TC 454 “Algae and
algae products”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
Introduction
This document has been prepared by the experts of CEN/TC 454 'Algae and algae products'.
The European Committee for Standardisation (CEN) was requested by the European Commission (EC) to
draft European standards or European standardisation deliverables to support the implementation of
Article 3 of Directive 2009/28/EC for algae and algae-based products or intermediates.
This request, presented as Mandate M/5471, also contributes to the Communication on "Innovating for
Sustainable Growth: A Bio economy for Europe".
The former working group CEN Technical Board Working Group 218 “Algae”, was created in 2016 to
develop a work programme as part of this Mandate. The technical committee CEN/TC 454 'Algae and
algae products' was established to carry out the work programme that will prepare a series of standards.
The interest in algae and algae-based products or intermediates has increased significantly in Europe as
a valuable source including but not limited to, carbohydrates, proteins, lipids, and several pigments.
These materials are suitable for use in a wide range of applications from food and feed purposes to other
sectors, such as textile, cosmetics, biopolymers, biofuel, fertilizers and biostimulants. Standardisation
was identified as having an important role in order to promote the use of algae and algae products.
The work of CEN/TC 454 should improve the reliability of the supply chain, thereby improving the
confidence of industry and consumers in algae, which include macroalgae, microalgae, cyanobacteria,
Labyrinthulomycetes, algae-based products or intermediates and will promote and support
commercialisation of the European algae industry.
Determining the nitrogen content of algae and algae products is an important method in the algae
industry. It is needed to calculate protein content, biomass gross composition, nutritional value, and also
to evaluate mass balances along algae farming.
The goal of this document is to give algae producers and algae products industries recommendations for
analytical methods for nitrogen content
...
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