ICUMSA News n°29 – 1996

Message from the President

Since raising the matter of my successor either by a new President operating in the present format or by some alternative arrangement involving a permanent secretariat, we have received a number of comments which are summarised below.

Since the French National Committee proposed Dr. Paul Mottard to succeed Mr. Dutton upon his retirement from the Publications Manager role, comments have been made suggesting a call for nominations to fill that position. Because the role of Publications Manager is affected by whether or not the permanent secretariat is pursued, I believe we need to resolve that issue first before seriously entertaining the appointment of Mr. Dutton’s successor. On the desirability of adopting a permanent secretariat further comments, following those from France have been received from Austria, Denmark, Germany, South Africa and West Indies. All are opposed to the permanent secretariat with the probable increase in the levy being a major impediment. The SPRI proposal to provide such a secretariat at a personnel cost of US$ 35,000 per year suggests there would be a significant increase in levy to fund this. At this time only the US and Canadian National Committees have enthusiasm for a permanent secretariat. The Chairman of the Canadian National Committee, Mr. Faviell did concede at the time of describing his concept that funding could be an issue.

The US National Committee and SPRI were given the opportunity to present their case for a permanent secretariat. Dr. Margaret Clarke, Managing Director of SPRI has responded and her letter appears below. The US National Committee has requested that a final decision on the permanent secretariat be deferred till the Berlin Session in 1998. In order to facilitate this, I propose to ask the Chairman of the Nominations Committee, Professor G. Mantovani, to call for provisional nominations for the next President. In the future issues of ICUMSA News we propose to give Presidential candidates an opportunity to present their manifestos for the future of the Commission. Of special relevance in this regard is the question of publications and the Commission’s relations with like-minded organisations.

Letter from Dr. Margaret Clarke

Sugar Processing Research Institute Inc.

A proposal has been made to ICUMSA by the President of the Board of Directors of Sugar Processing Research Institute Inc. (S.P.R.I.), that a permanent office for ICUMSA might be established at S.P.R.I. in the person of Ms Mary An Godshall. The Office would be responsible for meeting planning and organization, information collection and distribution, inquiry response, publications (books, press and electronic), coordination of collaborative studies, statistical work for ICUMSA and public relations. Details are in a letter, from the President of S.P.R.I.’s Board of Directors, sent to all Chairmen of National Committees (in August, 1994, and again in September, 1996). The presence of the office at an established research institute would eliminate overhead costs to ICUMSA. A supplemental assessment may be required in addition to funds that are currently available for publications, press and public relations, and travel,

Further information may be obtained from Sugar Processing Research Institute Inc. (fax number +1-504-282-5387).

Progress Report for General Subject 8:

Beet Sugar Processing

by Jean-Pierre Lescure, Referee

The position of General Subject 8 after the Havana meeting and the postal vote on the Accepted Status of three Methods in the Methods Book, can be summarized as follows:

1. Methods for process control have only an indirect effect on sugar trading. It was however decided to continue with this Subject in order to give the user knowledge of the accuracy and precision of the methods covered and to make available reference methods to factories engaged in quality assurance according to ISO 9000.

2. Pulp analysis was incidentally studied within this Subject in order to close a gap. The expected goal is to establish good agreement in respect of quality parameters to make it easier to control this co-product before it is sold.

3. Regarding the protocol for the Proficiency Testing of Analytical Laboratories, because it was recommended in Havana that this point concerned the Referee for Subject 3, General Subject 8 will not carry out work in this area.

4. Accepted status was approved by postal vote for Method GS 8/2/3/4-9 (Calcium by EDTA Titration), GS8/4/7-11 (Chloride by a Potentiometric Method) and GS8/4-15 (Raffinose and Kestoses by a Thin Layer Chromatography Method) with only three “conditional votes”. The Referee is studying these points in order to reach agreement with his Associate Referees.

5. Following discussions in Havana and then with the US National Committee, studies to eliminate lead clarification in laboratory work seemed unfounded, because it is widely practised in US factories and it was unnecessary to make it internationally uniform.

Recommendation 10 adopted in Havana thus became unwarranted.

Action during the 22nd Session

The main effort of the Referee, particularly during the two years since the Havana meeting, has been to try and solve the technical needs of sugar beet process control laboratories.

To improve the thinking in this area, some French Companies have given their assistance to the Referee and a working group set-up led by the Referee with the active collaboration of Jean Alliot, Jean-Marie Hochart, Michel Groult, Gérard Rousseau and Jean-Christophe Toury. The needs for processing were drawn up by the working group and priorities were submitted to the 16 Associate Referees for this Subject. Only six replies were received on these priorities. Though there was agreement on most points, it was noted that some Associate Referees were individually improving other points of general interest (e.g. Dextran determination in juices in connection with Leuconostoc-infected beet, laboratory centrifuge method to determine pressability of cossettes, etc…).

The Referee is awaiting communications on these points for the Report which will be presented in Berlin. Finally, the other main points retained were pulp analysis and enzymatic methods.

a) Pulp Analysis

The most urgent items were first to give guarantees to cattle breeders in respect of acceptable amounts of total sulphur and of exchangeable aluminium, and secondly to satisfy a demand in marketing for uniform methods for dry substance determination in pulp. Collaborative studies, mainly with French laboratories, but including the participation of laboratories from other countries, were agreed for testing draft methods which had been amended with the participation of animal feedstuffs manufacturers. It seemed advisable to delegate the organisation and the statistical calculations of some collaborative studies to an independent specialised body which was recognised for its ability internationally by both the food industry and the animal feed industry, viz. BIPEA (Bureau Interprofessionnel d’Etudes Analytiques, Gennevillers, France).

Other collaborative studies have been carried out, with limited participation, especially when they required costly items of equipment: e.g. atomic absorption. A comprehensive report on this point will shortly be sent to the Associate Referees and also to the Referee for Subject 3. Some studies which apparently fulfil IUPAC criteria could be proposed for Official adoption by ICUMSA.

b) Enzymatic Analysis

The aim was to provide the users with knowledge about the accuracy and precision of such specific and fast analytical methods which are often used rather than Official Methods for controlling the process.

Collaborative studies were organised with the protocols adapted to processing products (i.e. frozen juices, thick juice and molasses) using Kit methods which are commercially available. These studies consisted of glucose and fructose determinations, lactic acid (L and D) determinations, acetic acid determination and raffinose – only in molasses – determination.

The statistical analyses are not yet completed, but it is already clear that these methods can give more accurate values than conventional methods for the determination of reducing sugars.

These studies could serve to set up wider collaborative studies internationally, if their desirability is confirmed.

Council Directive 93/94 EEC on Hygiene of Foodstuffs

by Malcolm Burge, Referee, General Subject 3

In ICUMSA News of September Dr. Ruth Strauss gave a comprehensive résumé of the new food hygiene Directive and how this is being addressed by the sugar industry. There is however a further development in this area of legislation which has significant implications, primarily, but not exclusively, for the cane refining sector.

Annex 4 of the Directive covers standards for the bulk transport of foodstuffs and part processed foodstuffs.

Besides setting the hygiene standards it requires that the vessel/containers/tankers must be reserved for the transport of “foodstuffs only”. This naturally had serious implications for the international shipping of raw sugar as well as the movement of semi-processed syrups and thick sugar juices.

The food oils and fat industry was faced with a similar problem when transporting semi-processed materials and they were able to demonstrate to the EU authorities that contaminating residues from a previous, perhaps non-food cargo, could be eliminated by appropriate cleaning before loading and subsequent processing, so that final food product hygiene was not put at risk. This resulted in a derogation for this sector of the food industry and the preparation of a statutory and very extensive list of acceptable previous cargoes in transport, not for “foodstuffs only”.

The case for the sugar industry in the EU was coordinated and presented by CEFS (Comité Européen des Fabricants de Sucre), to the EU Standing Committee for Foodstuffs. It was at first suggested by the CEFS that a similar list of previous acceptable cargoes to that compiled for the edible oils and fats industry should be prepared. However, since this would include solid as well as liquid commodities this would present a daunting task if the list was to be fully comprehensive.

It was demonstrated that cleaning of transport and the removal of all significant quantities of possible contamination from previous cargoes was standard good practice in the sugar industry, and that subsequent refining and processing was sufficiently robust to remove possible trace contaminants. Indeed, this is the specific purpose of the refining process.

A series of potential hazards arising from contamination from previous cargoes were considered, such as, microbiological, heavy metals, plastic monomers, pesticides, fertilisers, ores and phenolic materials from coal and coke. HACCP studies were undertaken to demonstrate how these would be eliminated by the subsequent refining processes. We were also required to present an economic case, and it was estimated that to provide new, dedicated, shipping for the import of raw sugar into the EU alone would cost some 300 million US$.

The happy result of this negotiation was an agreement for the sugar industry to be granted a derogation from the Hygiene Directive Annex 4 covering transport of part-processed sugar products.

A new Directive covering the transport of part-processed sugar products has been drafted and hopefully will be finalised by mid-1997. This will describe the necessary cleaning of vessels and vehicles before loading, and appropriate labelling of goods, but will not require vessels, containers and vehicles to be “for food use only”:

Progress Report for Subject 8:

Chromatographic Techniques for Sugars.

by K.J. Schäffler, Referee

At the 21st Session of ICUMSA in Havana, two chromatographic procedures, tested by Subject 8, obtained Official status, these were:

1) The HPAEC procedure, described in Appendix 1 of the Referee’s 1994 Report [1], for the analysis of sucrose, glucose and fructose in cane molasses and sucrose in beet molasses.

2) The GC procedure, described in Appendix 8 of the Referee’s 1986 Report [2], for the analysis of sucrose, glucose and fructose in cane molasses.

These new chromatographic techniques together with existing ICUMSA Official methods can be used for most factory products encountered in the running control of sugar factories.

These chromatographic procedures however are not directly applicable to the analysis of low levels of invert in raw and white sugars. Several Referees, in their Recommendations, have requested that HPLC or GC techniques should be extended to these products because chemical methods like the Lane & Eynon method GS1/3/7-3 for reducing sugars in cane raw sugar, the Knight and Allen EDTA method GS2/3-5 for reducing sugars in white sugar and others (Luff-Schoorl, Ofner and the Berlin Institute) all suffer from lack of specificity. Additionally, these procedures will yield different results for samples having varying purities and it is also difficult to obtain the necessary accuracy with these methods.

There is a growing trend towards using chromatographic procedures for new agreements as the enhanced accuracy results in more consistent estimates of sugar quality and chromatographic methods will in addition be especially useful for the anticipated ICUMSA trials where a number of chemical methods will be tested (GS1, GS2 and Subject 15).

There is therefore a need for an Official chromatographic method for the determination of small amounts of invert sugar in white and raw sugar. Fortunately, du Boil has modified the Official HPAEC method in such a way that it is possible to determine low levels of glucose and fructose (10–30 mg/kg in sugar). The precision of the method can be gauged by studying the relative standard deviation for duplicate weighings. An average relative standard deviation of less than 5% was obtained for 38 sugars. It is therefore proposed that an interlaboratory collaborative test is organised.

Unfortunately, many laboratories do not yet have HPAEC facilities and, as it is important that the sufficient number of laboratories do participate, I would be grateful if potential participants would contact the referee as soon as possible. The trials are not only restricted to Associate Referees. The collaborative test will include 12 blind duplicates (white and raw sugar). Two test samples of known composition will also be sent to each participant as practice samples.


1 Proc. ICUMSA 21st Session 1994, 294–301

2 Proc. ICUMSA 19th Session 1986, 134–141

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