Toxicological evaluation of some food
    additives including anticaking agents,
    antimicrobials, antioxidants, emulsifiers
    and thickening agents



    WHO FOOD ADDITIVES SERIES NO. 5







    The evaluations contained in this publication
    were prepared by the Joint FAO/WHO Expert
    Committee on Food Additives which met in Geneva,
    25 June - 4 July 19731

    World Health Organization
    Geneva
    1974

              

    1    Seventeenth Report of the Joint FAO/WHO Expert Committee on
    Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 539;
    FAO Nutrition Meetings Report Series, 1974, No. 53.

    DIACETYL TARTARIC AND FATTY ACID ESTERS OF GLYCEROL

    Explanation

         These emulsifiers have been evaluated for acceptable daily intake
    by the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
    Ref. No. 13) in 1966.

         The previously published monograph has been revised and is
    reproduced in its entirety below.

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         Six male rats were fed 0.53 to 0.81 g/kg bw 14C-acetyltartaric
    acid ester of mono- and diglycerides (labelled in the two carboxyl
    groups of tartaric acid) as an oily solution. Within 24 hours only 26
    to 31% of the radioactivity was absorbed. Twelve to 20% of the
    radioactivity was eliminated as 14CO2 and 8 to 13% was excreted in
    the urine; 2% was found in the carcass (Lang & Schmidt, 1965). The
    analysis of the depot fat of dogs fed up to 20% of the substance for
    22 months showed no traces of either free or a fat soluble derivative
    of tartaric acid (Koppanyi & Dardin, 1950). The digestibility
    coefficient was over 90% of the substance or about the same as that of
    lard (Koppanyi & Dardin, 1950). In an aqueous medium diacetyl tartaric
    ester of mono- and diglycerides was hydrolyzed spontaneously to mono-
    and diglycerides and acetylated tartaric acid, the hydrolysis being
    somewhat accelerated by pancreatic lipase (Lang & Schmidt, 1965).
    There was some evidence that diacetyltartaric acid was also hydrolyzed
    in the body (Sourkes & Koppanyi, 1950).

    TOXICOLOGICAL STUDIES

    Acute toxicity

         No acute toxic effects at a practicable dose level have been
    demonstrated. Rats and rabbits tolerated intragastric doses of 30 g/kg
    bw and dogs 27 g/kg bw without any adverse effects. No diarrhoea was
    noted and autopsied animals showed no pathological changes.
    Histological examination of liver and kidneys of animals killed 10
    days after the administration of the substance showed no abnormalities
    (Koppanyi & Dardin, 1950).

    Short-term studies

    Dog

         Thirteen dogs each received daily i.v. injections of 0.5%
    suspensions of the substance in isotonic glucose at a dose rate of 40
    to 50 ml/kg bw for a total of up to 30 infusions. A fall in
    haemoglobin concentration occurred in 11 dogs and a pleural effusion
    in six. Groups of two three-year-old dogs were fed diets containing 0,
    5, 10 and 20% of diacetyl tartaric esters of mono- and diglycerides
    for 25-1/2 months. No specific effects attributable to the test
    substance were seen (Hartwig et al., 1962).

    Long-term studies

    Rat

         Groups of eight rats were fed 0, 5, 10 and 20% diacetyltartaric
    esters of mono- and diglycerides, another two groups were fed 50%
    white bread (bread control group) and 50% bread which was baked with
    the addition of 10% of the emulsifier in terms of flour weight (bread
    test group) for two years. No difference was found between the groups
    regarding body weight, external appearance, liver and kidney weights
    and mortality rate. Autopsies and histological examination of the
    major organs showed no changes attributable to the test substance. A
    second generation was maintained on similar regimes for 22 months.
    There was no difference between the groups regarding body weight,
    mortality and results of gross and histological examination. All
    litters were normal (Koppanyi & Dardin, 1950).

    Comments:

         Diacetyltartaric acid is not a natural constituent for the diet,
    and its low rate of spontaneous hydrolysis possibly allows the
    absorption of some unhydrolyzed compound. The experimental results
    show that the ester has a very low toxicity when given orally and that
    the acetylated tartaric acid moiety is absorbed only to a small
    extent. Evaluation is based on the available toxicological information
    and the results of the biochemical and metabolic studies.

    EVALUATION

    Level causing no toxicological effect

         Rat: 100 000 ppm (10%) in the diet equivalent to 5000 mg/kg bw.

    Estimate of acceptable daily intakes for man

         0-50* mg/kg bw.

    REFERENCES

    Hartwig, Q. L., Singleton, W. S. & Cotlar, A. M. (1962) Toxicol. Appl.
         Pharmacol. 4, 107

    Koppanyi, T. & Dardin, V. (1950) Unpublished report to WHO

    Lang, K. & Schmidt, B. (1967) Unpublished report to WHO

    Sourkes, T. L. & Kappanyi, T. (1950) J. Amer. Pharm. Assoc., sci. Ed.,
         39, 275

              

    *    The total food additive intake of tartaric acid should not exceed
    30 mg/kg bw per day.

    See Also:
       Toxicological Abbreviations