INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

    WORLD HEALTH ORGANIZATION



    TOXICOLOGICAL EVALUATION OF SOME
    FOOD COLOURS, EMULSIFIERS, STABILIZERS,
    ANTI-CAKING AGENTS AND CERTAIN
    OTHER SUBSTANCES



    FAO Nutrition Meetings Report Series 
    No. 46A WHO/FOOD ADD/70.36




    The content of this document is the result of the deliberations of the
    Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
    27 May - 4 June 19691





    Food and Agriculture Organization of the United Nations

    World Health Organization



                   
    1 Thirteenth report of the Joint FAO/WHO Expert Committee on Food
    Additives, FAO Nutrition Meetings Report Series, in press;
    Wld Hlth Org. techn.  Rep. Ser., in press.


    DISTARCH GLYCEROL

    Treatment with epichlorhydrin under alkaline conditions up to 0.3 per
    cent. tends to produce cross-linking at a rate of one glycerol diether
    linkage per 220 - anhydroglucose units.

    Biological Data

    Biochemical aspects

    Much evidence in the literature points to etherified starches being
    somewhat resistant to enzymic degradation. Probably small fragments
    containing the ether linkage will remain and will not be absorbed
    readily. Any material absorbed is likely to be excreted by the kidney.
    No direct experimental evidence exists for this particular hypothesis.
    (French, 1960), The metabolic fate of methylglucose is cited as
    collateral evidence. Although methylglucose is absorbed by rats (Sols,
    1956) no demethylation is believed to occur (Czáky & Wilson, 1956) and
    excretion is essentially quantitative (Csáky & Glean, 1957). The
    caloric value of two starches treated at levels of 0.07 per cent. and
    0.50 per cent. epichlorhydrin were estimated by comparing the weight
    gain obtained after feeding a basal diet supplemented with 3 g of each
    starch against a dose-response curve obtained by feeding daily sucrose
    supplements of O, 1.5 g, 3 g, 4.5 g and 6 g equivalent to
    approximately 0, 6, 12, 18 and 24 calories. Distarch glycerols were
    only slightly lower in caloric value than unmodified starch, the
    differences not being significant. No details were available on the
    number of rats used or the length of feeding of a given
    supplementation (Oser, 1960).

    Acute toxicity

    None available.

    Short-term studies

    Rat. Groups of 10 male and 10 female rats were fed for 90 days
    unmodified starch or starch treated with 0.07 per cent.and 0.50 per
    cent. epichlorhydrin at 71 per cent. of their diet.  The efficiency of
    food utilization was similar as between all groups. Haematological
    investigations showed no abnormalities related to the feeding of
    modified starches. Non-protein nitrogen and sugar levels in the blood
    remained normal in all groups. The weights of kidney, liver and
    adrenals were normal and no histopathological changes were seen in the
    liver or kidney. Only a summary report was available (Oser, 1960).

    Long-term studies

    None available.

    Comments

    Although only minor structural modifications are stated to be present
    in this material the biological information provided lacks full
    particulars and was not adequate for evaluation. No experimental
    evidence was provided on the metabolic fate of this compound. Adequate
    metabolic studies preferably in man as well as 90-day studies in two
    species (one a non-rodent mammal) are required.

    EVALUATION

    Not possible on the data available.

    REFERENCES

    Csáky, T. Z. & Wilson, J. E. (1956a) Biochem. Biophys. Acta., 22,
    185

    Csáky, T. Z, & Glenn, J. E. (1956b) Amer. J. Physiol., 188, 159 

    French, D. (1960) Communication to T. A. White, 20th January 1960

    Oser, B. L. (1960) Unpublished report by Food and Drug Research
    Laboratories Inc., 4th January 1960, submitted by National Starch
    Products Inc.

    Sols, A. (1956) Rev. esp. Fisiol., 12, 17
    

    See Also:
       Toxicological Abbreviations
       Distarch glycerol (WHO Food Additives Series 1)
       Distarch glycerol (WHO Food Additives Series 5)
       DISTARCH GLYCEROL (JECFA Evaluation)