34th ICUMSA Session 2025

Final Recommendations

GENERAL SUBJECT 1 – Raw Sugar

Referee: Tim Thys (The Netherlands)

Recommendations

  1. Update Method GS1-1 (2022) to include the use of Carrez reagents or other clarification agent alternatives to basic lead acetate.
  2. Update Method GS1-2 (2022) to ensure that an appropriate amount of filter aid is used. Specifically, modification of the current phrasing within the Method from “approximately 3.5 g Celite” to “if needed, add few grams of filter aid (up to 3.5g is recommended for turbid samples)”.
  3. Adopt the proposed particle size distribution method in Annex 2 for raw sugar.


GENERAL SUBJECT 2 – White Sugar

Referee:  Monique Steegmans (Belgium)

Recommendations

  1. The work to finalise the details for the determinations of sulphite in white sugar by an iodometric method shall be continued. The results should be validated against the ICUMSA® Method GS2-33 (2022).
  2. A draft method, based on Recommendation 1, shall be produced and sent to Associate Referees for comment.
  3. A collaborative study of the draft method of Recommendation 2 shall be organised.
  4. Further work shall be done to determine if ICUMSA® Method GS2-19 (2007) can be extended or adapted to be suitable for the determination of insoluble matter in raw sugar.


GENERAL SUBJECT 3 – Speciality Sugars

Referee:  Andreas Georg Degenhardt (Germany)

Recommendations

  1. The revised version of ICUMSA® Method GS9-8 (to be proposed at the 34th Session) should be evaluated to determine if it can be extended to sugar products with colour in solution values of more than 16,000 IU, such as Muscovado sugars. This requires coordination between the GS3 and GS9 Referees and the provision of sufficient test materials by the respective manufacturers.
  2. If the evaluation suggested in Recommendation 1 indicates Method GS9-8 can be extended to sugar products with higher colour in solution values than 16,000 IU, an international collaborative study should be performed to provide validation for the higher colour in solution range.
  3. Under the direction of the GS3 Referee, a method using an amino stationary phase, an HPLC method will be written in ICUMSA format and tested in collaboration with the Referees from GS4, GS6 and GS8 for the products sucrose syrup, invert sugar syrup, beet brei (pulp/mush), thick juice and molasses.
  4. If the results obtained from the Recommendation 3 work support the intended use of HPLC analysis for the defined products, the GS3 Referee should organise an international collaborative study to validate the analytical method according to ICUMSA® performance standards.


GENERAL SUBJECT 4 – Molasses

Referee: Sebastiaan van Berchum (The Netherlands)

Recommendation

  1. Method GS4-1 (2013) should be updated to include the use of Carrez as a clarification agent for molasses samples with a colour below 180,000 IU and a turbidity below 30,000 IU.
  2. Further investigation of the use of other filtration aids (e.g. Zinc powder/activated carbon) and clarification agents for molasses samples with a colour above 180,000 IU and a turbidity above 25,000 IU should be done, to enable the removal of the requirement to use Basic Lead Acetate for determination of polarimetric sucrose content from Method GS4-13.


General Subject 5 – Cane

Referee:  Mathilde Mellin (France)

Recommendations:

No new recommendations.


GENERAL SUBJECT 6 – Beet

Referee: Ulf Strijowski (Germany)

Recommendations

  1. Data on beet sampling and brei preparation should be collected using a questionnaire containing anonymised data.
  2. Sampling procedures for sugar beet and preparation of beet brei should be described and published as an ICUMSA® Specification and Standard.
  3. An international ring test for marc content in sugar beet brei should be performed, following the ICUMSA® regulations.
  4. An ICUMSA® method for the analysis of marc content in beet brei should be prepared for approval.


GENERAL SUBJECT 7 – Cane Processing

Referee: Gillian Eggleston (USA)

Recommendations:

  1. Conduct and complete an Inter-Laboratory analysis test of the Method GS7-36 (2024) Spectrophotometric Determination of Total, Soluble and Insoluble Starch in Cane Raw Sugars using Microwave-Assisted Neutralisation – Tentative.
  2. Draw up an ICUMSA® method on the “Determination of the Polarimetric Analysis for Cane Juices, Syrups, Molasses and Raw Sugars using an automatic filtration equipment – Tentative” and conduct an intra-laboratory analysis test.


GENERAL SUBJECT 8 – Beet Processing

Referee: Florian Emerstorfer (Austria)

Recommendations:

  1. The proposed revision of Method GS8-19 “The determination of dextran in beet raw juice and thick juice by a modified alcohol haze method – Tentative” should be adopted and the status changed to “Accepted” with respect to Raw Juice.
  2. Organisation of coordinated cooperation between GS7 and GS8 with respect to use of a dextran antibody test kit to be arranged to enable discussion of suitability of use and application.
  3. Review of all GS8 ICUMSA® Methods, including frequency of use, to be via a questionnaire to the GS8 Associate Referees.


General Subject 9 – Plantation White Sugar

Referee: Vasudha Shirish Keskar (India)

Recommendations

  1. Based on the single laboratory method validation data presented at the 33rd Session of ICUMSA and findings of the 2025 GS9 report, Method GS2-33 (2022) “Sulphite in White Sugar by the Rosaniline Colorimetric Method“, should be updated to include details required for testing of plantation white sugar.
  2. The proposed revision to Method GS9-8 (2011) “The Determination of Sugar Solution Colour at pH 7.0 by the MOPS Buffer Method – Official (Reference)”, should be adopted to replace the current published method.
  3. The work on alternative method to GS2-19 (2007) “The Determination of Insoluble Matter in White Sugar by Membrane Filtration – Official “should be continued for plantation white and specialty sugar.


SUBJECT 1 – Articles of Association and By-Laws

Referee: Martijn Leijdekkers (The Netherlands)

Recommendations

No new recommendations.


SUBJECT 2 – Method Format, Collaborative Testing and Statistical Treatment of Data

Referee: N.N.

Recommendations

No report; No recommendations.


SUBJECT 3 – Colour, Turbidity and Reflectance Measurement

Referee: Christiane Lakenbrink (Germany)

Recommendations

  1. Further work must be done to find an alternative to replace the PTB as independent institute for calibration of the ceramic tiles nominated in method GS2-13.
  2. The finalised document containing an overview of ICUMSA®’s current analytical methods and the associated EU provisions should be published on the ICUMSA® webpage.


Subject 4 – Physical Methods

Referee: Mathis Kuchejda (Germany)

Recommendations

  1. Finalise the revised version of SPS-1 after discussion of all the issues raised, so that it can be published after the calculations have been double-checked by at least two persons. The format of the SPS-1 will be finally decided by the ICUMSA® Officers and the Publication Committee.
  2. Update all ICUMSA® Methods that relate to determination of polarimetric sucrose content with the relevant information from the agreed revision of SPS-1 (Recommendation 1).
  3. Continue monitoring USP and EP regarding the use of polarimetry, refractometry and density.


Subject 5 – Chemical Methods

Referee: Maciej Wojtczak (Poland)

Recommendations

  1. ICUMSA® Method GS4-2 (2002), “The Determination of Sucrose by Gas Chromatography in Molasses and Factory Products – Official; and Cane Juice – Tentative” should be rewritten as GS4-2, “Sucrose by Gas Chromatography in Molasses – Official”.
  2. If there is sufficient interest in an ICUMSA® Method that uses gas chromatography for determination of sucrose in other factory products, such a Method should be written.
  3. Further investigations of dextran analysis methods should be conducted in cooperation with GS8 and GS7.
  4. ICUMSA® Method GS2-54 (2017), “Determination of Non-Ionic Surfactants in White Sugar, Molasses and Dried Beet Pulp – Tentative”, should be updated to replace the requirement to use chloroform.
  5. Further development of titration methods towards automatic endpoint determination should be considered in cooperation with referees of GS1, GS2, GS3, and GS4.


Subject 6 – Microbiological Methods

Referee: Michael Klingeberg (Germany)

Recommendations

  1. The new format rewrite of ICUMSA® Method GS2-45 is done. The Method should be extended to include the Mayeux-Sandine-Elliker (MSE) medium and be published as GS2-45 (202x) “Slime-forming Bacteria in White Sugar by Membrane Filtration or Pour Plating – Accepted”.
  2. The ICUMSA® Method GS2-50 “Thermophilic Acidophilic Bacteria (TAB) and Guaiacol producing TAB (GP-TAB) in Sugar Products should be extended by the determination of TAB and GP-TAB in those products that cannot be filtered over a 0.2 μm membrane filter.
  3. The definition of the terms e.g. sugar, sugar products, dark syrup, refined sugar products should not be specifically defined with respect to microbiology methods within the ICUMSA® Methods Book. ICUMSA® Methods based on microbiological tests should instead differentiate between sample types based on filterability only (Membrane Filtration or Pour Plating).
  4. Further work (single laboratory tests and proficiency tests) should be performed to validate the ICUMSA® Methods for microbiological testing of liquid sugar.


SUBJECT 7 – Sampling, Sample Handling and Sample Preparation

Referee: Alan N. Mead (United Kingdom)

Recommendations

  1. A sub-committee should be formed, comprising those with the necessary skills and access to suitable facilities, to further study and to quantify the errors attributable to Sample Handling and Sample Preparation.
  2. In conjunction with the GS5 Referee, the procedure for cane preparation be written for inclusion in Standards and Specifications in a similar manner to that of beet.