ICUMSA News n°44 – 2002

Editor: Rud Frik Madsen

Message from the President

As pointed out in the new page of our website ( ), the organization for the next Session, which will be held in Pune (India) from 3rd to 7th June 2002, is going forward thanks to the cooperation of our Indian friends, and in particular of Mr. Kumar.
Although it was set down that the organizational details, even if included in internet, have to be sent to the Chairmen of the National Committees and Referees via e-mail or post (to give complete coverage), we believe that it is useful that they are reported also in the ICUMSA News. Therefore, you will find in the following pages a message from Mr. Kumar, the provisional program, application forms, and some other information.
I trust that the Referees have already started their work, collecting data and preparing their Reports to be presented at the next Session. Although, at the moment, I have only received the Report on Subject N. 6 from Mrs. Leblebici, Turkey, I hope to receive the most of the other reports within December 31st , as provided.
As soon as they are received, and I hope that all the Referees will be able to send them to me by e-mail, they will be include in a special page of our website. If some Chairmen would like to receive them by mail, please let me know. With the purpose of facilitating both the reading of the Reports and publication of the Proceedings, I earnestly request the Referees to send me the text in English, after careful editing.
Furthermore, following this short message you will find an overview concerning the organization of ICUMSA which was written by Dr. Phadnis of the Vasantada Sugar Institute of Pune. I believe that it can be useful in preparation of the next Session and in particular for persons who are not very familiar with the aims, history and organization of our Commission.

The Sugar Technologists’ Association of India, C, Block, IInd Floor, Ansal Plaza, August Kranti Marg, Andrews Ganj, New Delhi – 110 049

Message from Mr. Kumar







Dr. S. P. Phadnis,
Vasantdada Sugar Institute, Manjari, Pune 412 307

Sugar has become such an essential part of our daily life that one can hardly imagine life without it. Sugar has been known to man for about the last five thousand years. It has been an important commodity in international trade for more than six centuries, spanning the entire evolution of the organic chemical industry. Thus, it was traded internationally centuries before the current global economy became common. It is noteworthy that different countries were producing sugar using different raw materials and different techniques; yet could arrive at a mutually acceptable trade value of this sweet disaccharide during their commercial transactions. This was possible because various essential pre-conditions had been fulfilled. One such condition was the successful development of the relevant metrology (i.e. the scientific study of weights and measurement) stimulated by ICUMSA.

What is ICUMSA
ICUMSA is a short form of the expanded name of an organisation called The International Commission for Uniform Methods of Sugar Analysis. This Commission was started by a meeting of the European chemists representing the sugar industries of their countries. The Commission was appointed for an express purpose viz. the standardisation of quartz plates used in the analysis of sugar. In its first meeting, however, ICUMSA decided to broaden the scope of its activities. It took upon itself the responsibility of defining, by agreement, the techniques which should be applied in order to determine the composition of sugar products in regard to their constituents for the purposes of pure scientific research as well as for business transactions. Today, ICUMSA is a worldwide body which brings together the activities of the National Committees for sugar analysis in over 30 countries. ICUMSA, thus, carries out a work of criticism, studying imperfections of the existing methods including reasons for their limitations, in order to improve them and make them more accurate, precise and dependable. ICUMSA also plays a creative part in the development of new methods and in adapting techniques developed by science. In the scientific field, ICUMSA was one of the first examples of international collaboration as it held its first meeting in Hamburg in 1897. ICUMSA was one of the first groups to organise international scientific meetings and the oldest international body for the standardisation of analytical methods in any particular branch of industry.

Origin of the Commission
The first suggestion of an international commission was mooted at an international conference of chemists held at the Beetroot Sugar Association in London on September 9th,1896. During the conference Dr. Alexander Herzfeld, a German scientist, proposed the use of quartz plates as the standard in the determination of polarisation. It was also proposed that each plate be certified by an International Commission to be appointed at a later date. In the absence of such an arrangement confusion would have prevailed in international trade with regard to uniformity in methods of measurement.

The First Session
ICUMSA held its first session on June 12, 1897 at Hamburg in Germany. It was chaired by Dr. Alexander Herzfeld. Participants for the session came from the sugar beet producing countries of Germany, Austria, Italy, France, Belgium and the USA. Deliberations were held on methods of examination and selection of quartz plates. The temperature of polarisation and of quartz plates was fixed at 200C. The weight of sugar to be taken for the analysis was fixed at 26 g in 100 ml. Additional methods and means were also suggested to decrease the differences in the polarisation work and it was considered desirable for an endeavour to be made to introduce uniformity of analytical methods for the beet sugar products.

Subsequent Sessions
It can be seen from the enclosed Table that until 1912 Icumsa held its sessions every two or three or four years. The Paris session of 1900 was different inasmuch as a sugarcane producing country (Java) participated for the first time in the ICUMSA meeting. In the Berne session of 1906, the duties of the Commission were designated to be purely analytical, emphasising a precise and specific purpose for the Commission. It is significant that many societies and associations also discuss technical and scientific matters relating to sugar. Furthermore there are international associations for technologists for the cane sugar and the beet sugar industry. Only one organisation (viz. ICUMSA) exists which had been and would continue to be solely concerned with the unification of methods of sugar analysis.
There was a gap of 20 long years between the 7th and the 8th sessions. In this intervening period, Dr. Frederick Bates, an American scientist, travelled from one sugar producing country to another, maintained contacts with their industries and ultimately succeeded in organising a session at Amsterdam in 1932. Four years later, the 9th session was held in London, but again there was an interruption, this time due to world war II. The sessions scheduled in 1940 at Berlin and in 1948 at Prague were abandoned. It was only in 1949 that the 10th session could be held in Brussels. This was by far the most successful convention of ICUMSA in the first half of the last century. It once again preserved the name of the Commission and also the continuity of its purpose. The 11th session of Paris originally scheduled in 1953, coincided with the ascent to the throne of Queen Elizabeth II of the U. K. on June 12, 1953. The session was shifted to 1954 at the request of many sugar producing countries which wanted to take part in the ceremony. Since then ICUMSA has been organising its sessions regularly every fourth year.
Indian participation in ICUMSA sessions started in the second half of the century. During the last quarter of the last century, the number of participating delegates and countries seems to have stabilised between 120-140 and around 27 respectively.

There are 4 well defined and well documented objectives of the Commission:.
(a) To provide an International forum for all matters concerning methods of sugar analysis.
(b) To promote the study of methods of analysis of sugar and of products and materials ancillary to sugar production.
(c) To provide for interchange of information among the countries involved.
(d) To agree upon and publish international recommendations for uniform methods of sugar analysis.

Any country can join the Commission as a member. Even a non-member country can participate in its deliberations. However, the latter has no voting right. Any country willing to join the Commission is initially required to form a National Committee for methods of sugar analysis. In the formation of the said National Committee various other organisations within the country which are interested in the production, testing, utilisation, import-export etc. of sugar are invited to be involved.

ICUMSA is supported by contributions from member countries. It is the responsibility of each National Committee to ensure that contribution to ICUMSA is paid on time. The Commission adopts a budget for the necessary expenses at each of its plenary sessions. The period of budget extends from a given session to the next session when total contribution and its division among members is fixed. This is done on the basis of units. One unit means 100,000 tonnes of sugar produced plus imported by the country. The total contribution of a country is limited to 12 units.

The number of votes which each National Committee is entitled to is also determined by units. If the country holds less than 3 units, then it is entitled to one vote. If it has got between 4 and 6, 7 and 12 or above 12 units, then it is entitled to 2, 3 or 4 votes respectively.

The Governing Body
There are two administrative wings of ICUMSA namely the Executive Committee (EC) and the Administration (Adm.). The former is the governing body and the latter is responsible to the former. The EC comprises the president, the immediate past president, all vice presidents (at present there are 10), the general secretary, the treasurer and one or more representatives appointed by each National Committee. The Adm. comprises the president (who presides over all the meetings), all vice presidents, the general secretary (who looks after correspondence and all work in the general secretary’s office) and the treasurer (who supervises accounts and approves all payments). The treasurer is usually assisted by two chartered accountants.
There may be appointed a third body, called The Committee of Action for special and specific purposes. It comprises all members of Adm. mentioned above plus 3 chairmen of National Committees selected by the president. It is also responsible to EC.
The entire responsibility for the affairs of the Commission including its property, funds, admission and ejection of members etc. is shouldered by the EC. The term of officers is from the adjournment of one plenary session to and including the following session. All officers of the Commission serve without any monetary compensation.

Plenary Sessions
The ordinary sessions of the commission take place every four years. Time and place of each session is pre-decided by the Adm. and EC in consultation with the National Committees. The official language of the Commission is English, but contributions can be made in French or German. Reports, recommendations, documents etc. of the Commission are, however, published in English. National Committees are free to translate these into their own languages.

Collaborative Studies
An important aspect of ICUMSA activity is collaborative studies. The Commission has recognised several subjects or areas of work for this purpose. These are broadly divided into two categories viz. the general and the technical. The former is regarded as being at the forefront of the interface of the Commission with the industry including suppliers, consumers and authorities. Each subject of the latter group is concerned with one particular field of sugar industry. At present, there are 25 subjects including 9 general subjects. But this number can change according to needs.

Technical Committees
For each subject there is a technical committee (TC). It comprises a Referee and several Associate Referees who are appointed by the President. There are well defined guidelines for the work of referees and associate referees. Their term continues till the TC
is discharged or the president advises them of their replacement by other individuals. At present, there are some 25 referees and 350 associate referees spread throughout the world. Recommendations of the TC are submitted through the president to the EC for consideration. EC can adopt any resolution at a plenary session or by means of a postal ballot. Once accepted, the resolution becomes the official recommendation of the ICUMSA.
The validation of any analytical method is done by collaborative studies according to internationally recommended protocol. Since 1990, ICUMSA has officially recommended the use of the 1987 IUPAC (International Union of Pure and Applied Chemists) protocol.
The collaborative studies involve four steps viz. development of a method, its validation, its publication and its revision/revalidation. A method can be developed, in house, by any laboratory out of interest, need, research or otherwise. If found promising, its repeatability and reproducibility is checked in collaborative testing during which the participating laboratories are not allowed to introduce any variation in the given method. After satisfactory validation, the method is sent out to members. Revision and revalidation of the method is carried out as may appear necessary. The method is given tentative status when first submitted and Official status upon meeting all requirements of the Commission. The methods which are demonstrably useful and have found an established application, but which do not lend themselves to collaborative testing are given an Accepted status.

Relevance of ICUMSA
In view of the growing specialisation of chemical analysis, ICUMSA started reorganisation of its Subjects after the 1986 session. It has, however, maintained the central theme of trade analysis. Within the framework of Codex Alimentarius rules, the ISO as well as Food and Sugar Market Legislations of various countries, the competent work of ICUMSA in the world sugar sector is an important requirement.

Contributions of Vasantdada Sugar Institute (VSI)
There was little awareness about ICUMSA in this country until a decade ago. It was only around 1994-95 that our sugar industry started realising its significance. During that year the country produced a record 14.6 million tonne of sugar and the government allowed some export of the commodity. However, the importing countries would accept only that sugar which conformed to ICUMSA specifications with regard to colour, for example. Since many sugar mills interested in the export of sugar were unaware about ICUMSA at that time, its specifications, its methodology etc. they approached VSI for the necessary information. Since the Institute was already working on the analysis of sugar, it could quickly answer the queries raised by the industry. VSI is largely responsible in creating awareness about ICUMSA in the Indian sugar industry through various seminars, workshops and research publications. Since 1999 the Institute has been organising a two-week training programme on ICUMSA methods of sugar analysis during off season for the benefit sugar technologists working in the industry, and the response of the industry to it has been very encouraging.

Other Activities
One of the important functions of the Commission is, of course, to publish the accepted analytical methods in the form of Methods Book and to update it whenever necessary. New methods, specifications, standards etc. may appear in the form of supplement to the said Methods Book. The commission also publishes proceedings of its general assemblies and sessions. The commission has its own website (see below). Whenever some special occasion is to occur (e.g. a general assembly and session), special pages are prepared and added to the website so that full information about the forthcoming event is available to users well in advance.
The Commission publishes “ICUMSA News” three times in a year in five International journals in seven languages (viz. English, French, German, Italian, Spanish Czech and Arabic). In recognition of outstanding services rendered by individuals for the cause of ICUMSA, the Commission gives them honorary membership in various categories like, for example, lifetime presidentship given to Dr. A. Herzfeld and to Dr. F. Bates. At present, ICUMSA has no permanent secretariat but it is toying with the idea of having one in the near future.

Further Information

1. VSI library: Icumsa Proceedings.
Vasantdada Sugar Institute,
Manjari, Pune 412 307
Ph. (020)6993988/89/94/95
Fax.: (020) 6992735
E-mail: vsilib@giaspn)

2. President,
Sugar Technologists’ Association of India,
“C” Block, 2nd Floor, Ansal Plaza
August Kranti Marg, Andrews Ganj,
New Delhi: 110 049
Tel..: 0091 11 6263694-95
Fax.: 0091 11 6263695

3. Prof. G. Vaccari,
University of Ferrara,
Ferrara, Italy
Fax: 39 0532 291168

4. Web site:


Session Place Year Deleg./Countries
1 Hamburg 1897
2 Vienna 1898
3 Paris 1900
4 Berlin 1903
5 Berne (Switzerland) 1906
6 London 1908
7 New York 1912
8 Amsterdam 1932
9 London 1936
Berlin (1940)
Prague (1948)
10 Brussels 1949
11 Paris (1953) 1954
12 Washington 1958 99/14
13 Hamburg 1962 90/22
14 Copenhagen 1966 98/24
15 London 1970 98/25
16 Ankara 1974 140/27
17 Montreal 1978 120/27
18 Dublin (Eire) 1982 120/27
19 Cannes ( France) 1986 118/28
20 Colorado Spring 1990 122/27
21 Havana (Cuba) 1994 140/27
22 Berlin 1998 140/25

Activity within Subject 12: Microbiology

Eberhard Stoppok, (Germany), Referee for Subject 12

In 1999 a circular was sent to remind all Associated Referees of the work resulting from the recommendations given in Berlin. All Referees were asked finally for their intention to participate in the work planned for Subject 12. Some Referees informed me about their work resulting from the recommendations of the 22nd session in Berlin. It is my intention to inform the reader about progress in experimental work for subject 12 carried out since the last session.

Method for sampling liquid products

A few proposals for sampling liquid products from different sugar factories are available to complement the method for sampling crystalline sugar. They differ only slightly in handling conditions and will be evaluated in the Referees report.

Determination of dying-off rates of pathogens in crystalline products

Resulting from the circular a few Referees showed interest in a collaboration on this work and asked about test conditions. Detailed information was sent in a circular in March 2000 mainly including instructions for the determination of dying-off rates. Three strains (Salmonella typhimurium, Escherichia coli, Enterococcus faecalis) were selected for the dying-off rates as they were available for everyone from ATTC or Oxoid.

Some proposals were also given for the contamination of sugar as no suitable method existed and one had to be developed. It was expected that spraying of crystalline sugar with a bacterial suspension might be disadvantageous because of modification of the crystal surface and formation of agglomerates. The use of microbank rings inoculated with a cell suspension of pathogens was preferred. With this method a reproducible infection of up to 40 million CFU/10 g sugar was achieved (CFU: colony-forming unit). It should be noticed that such an infection is abnormally high but is helpful to pursue the survival for a longer period to estimate dying-off rates (with a low infection of 1000 CFU/10 g sugar no germs were detectable after 3 days of incubation).

For the recovery of pathogens, Standard I Nutrient Agar was used as a universal medium. Additionally, selective media for the above-mentioned strains were recommended. These were Mac Conkey Agar for E. coli, XLD Agar (Xylose-Lysine-Desoxycholate Agar) for Salmonella and CATC Agar (Citrate-Azid-Tween-Carbonate-Agar) for Enterococcus.

Diploma work about the dying-off rates of pathogens was also arranged which is now finished and shows results comparable to those which were sent by a Referee. After the infection a drastic decrease of microbial germs was observed with all pathogen groups. When crystal sugar was infected with Salmonella at a rate of 40 million CFU/10 g it was still detectable after 100 days, but the reduction of CFU was 99.8 % at this time. From the other pathogens dying-off rates of the same range were observed at incubation times of 20 days (E. coli) and 60 days (Enterococcus). All results show very clearly that pathogens decrease drastically in crystal sugar during storage.

Test of chromoculture media of various companies with the aim of establishing a method for detecting E. coli or Enterobacteria as an indicator for possible contamination with pathogens.

A simple test for the detection of these bacteria groups would be helpful. Hence a comparison with different chromogenic media would be helpful to establish a method for the detection of E. coli or enterobacteria as an indicator for possible contamination with pathogens. Therefore, chromoculture media of Dr. Möller &Schmelz, bioMérieux, Merck and Oxoid were compared by a Referee for their handling and their suitability to detect these bacteria groups. For the determinations white filters were preferred as they facilitated the detection of coloured colonies.

The media from Oxoid and bioMérieux showed clearer identification of germs than the others but the medium of bioMérieux was preferred as the interpretation of germs was unequivocal.

Further recommendations from the last session concerning methods of detection of lactoacid bacteria, osmophilic yeasts and fermentability will be evaluated and projected in a method for liquid sugar in the Referees report.

Activity within Subject 13 Reducing Sugars

Dr. (Mrs.) V. S. Keskar Referee for Subject 13.

International collaborative tests were conducted for three methods under the programme of ICUMSA subject S-13. The work was based on the following aspects.

  1. Previous study under this subject was conducted by Mel Carter (Denmark). In the report of 22nd session of ICUMSA (Berlin) it is mentioned that the Modified Ofner method gave satisfactory results in only two of the five white sugar samples containing the higher levels of reducing sugars i.e. 0.035 % and 0.085 %. The average repeatability and reproducibility values obtained by this method were the best values achieved in comparison of four methods viz the Berlin Institute Titrimetric (Method GS 1-5) the Lane and Eynon (GS1/3/7-3), and the Modified Ofner Titrimetric Method (GS2-6). The first three methods were tested for RS analysis of raw sugar whereas the Modified Ofner method was tested for analysis of RS in white sugar.
  2. In the collaborative study conducted by present Referee the Modified Ofner method has be studied for a wide range of RS levels in white sugar. The selected range was from nil to 0.09% RS.
    A total of ten samples were included in this study, of which seven were below 0.05
    % and three were above 0.05 %. Five of the lower level RS samples were prepared by Mr. Mel Carter by spiking low RS containing white sugar and remaining to were natural plantation white sugar samples. In the set of high-level RS sugars three spiked samples were prepared by referee’s laboratory. This study was conducted with the 10 samples (in blind duplicates).
    The other method included in this programme is Knight & Allen (GS2-3/5 Method). This method is the Official Method from 1997 and is suitable for the determination of reducing sugars up to 0.02 %. For sugar with high invert level it is recommended that the sample be diluted with low invert sucrose (diluent) by reducing the actual sample weight from 5g to a lower figure. In a collaborative test conducted in 1998 it is shown that by diluting the original sample the accuracy of the method is lost. The method was revised in Geoff Parkin’ laboratory and readjusted up to 0.05 % without the sample dilution step. The revised method was tested in the recent collaborative study for 7 samples containing less than 0.05% RS. From these samples 5 were spiked and two were natural.
    The third method is the new enzymatic method developed and proposed by Dr Gunter Pollach, Austria. The method is suitable for analysis of white sugar containing up to 0.04 % of invert sugar (glucose + fructose). The principle of method is as follows.
    D-glucose and D-fructose are phosphorylated by hexokinase (HK) and adenosine-5′-triphosphate (ATP) to D-glucose-6-phosphate (G-6-P) and D fructose-6-phosphate (F-6-P), with the formation of adenosine-5’diphosphate (ADP). F-6-P is then converted by phosphoglucose-isomerase (PGI) to G-6-P. G-6-P is oxidized in the presence of the enzyme G-6-P-dehydrogenase (G6P-DH) by nicotinamide-adenine-dinucleotide-phosphate (NADP) to D-gluconate-6-P. Reduced nicotinamide-adenine-dinucleotide-phosphate (NADPH), formed by the oxidation of G-6-P, is measured photometrically by its characteristic absorbance at 340 nm:

D-glucose + ATP G-6-P + ADP

D-fructose + ATP F-6-P + ADP

F-6-P G-6-P

G-6-P + NADP+ D-gluconate-6-P + NADPH + H+

Seven samples in blind duplicates were tested for this method.
The work of the collaborative test was initiated in March 1999. The samples were dispatched in June 2001. All results were received within three months and the results are now under statistical analysis.
A total of ten laboratories have participated for the modified Ofner method, nine laboratories for the Knight and Allen method and twelve laboratories for the new enzymatic method.
Mr. J. V. Dutton UK and Mr. M. Carter Denmark have contributed a great deal for this programme.