WHO/Food Add./24.65
    FAO Nutrition Meetings
    Report Series No. 38A




    SPECIFICATIONS FOR IDENTITY AND 
    PURITY AND TOXICOLOGICAL EVALUATION 
    OF SOME ANTIMICROBIALS AND 
    ANTIOXIDANTS





    The content of this document is the result of the deliberations of the
    Joint FAO/WHO Expert Committee on Food Additives which met 8-17
    December 1964a





                   

    a Eighth Report of the Joint FAO/WHO Expert Committee on Food
    Additives, Wld Hlth Org. techn. Rep. Ser., 1965, 309; FAO
    Nutrition Meetings Report Series 1965, 38.


    TARTARIC ACID

    CHEMICAL NAMES        Tartaric acid; 2,3-dihydroxysuccinic acid

    EMPIRICAL FORMULA     C4H6O6

    STRUCTURAL FORMULA    HOOC - CHOH - CHOH - COOH

    MOLECULAR WEIGHT      150.09

    DEFINITION            Tartaric acid contains not less than 99.5% of
                          C4H6O6 after drying to constant weight at
                          105°C.

    DESCRIPTION           A colourless or translucent, odourless,
                          crystalline solid with an acid taste.  1 g is
                          soluble in 0.8 ml of water or 3 ml of ethanol.

    NATURAL OCCURRENCE    Tartaric acid occurs in many fruits, either
                          free or combined with potassium, calcium or
                          magnesium.  It may constitute from 60-80% of
                          the non-volatile acid in wine.

    USE                   As a synergist with antioxidants and as an
                          acidic constituent in some baking powders.

    Biological Data

    Biochemical aspects

    Tartaric acid is metabolically inert in the human body.1,2,3,4  When
    taken by mouth, only about 20% of ingested tartrate is eliminated in
    the urine; the reminder is not absorbed but destroyed in the
    intestinal tract by bacterial action.

    Acute toxicity

    In the mouse, the LD50 of the sodium salt administered by mouth was
    found to be 4360 mg/kg body-weight.5

    Tartaric acid administered by stomach tube in a dose of 5000 mg/kg was
    fatal to a dog.6

    Three out of 7 male rabbits died following oral administration of
    disodium tartrate in an average dose of 5290 mg/kg; while 6 male
    rabbits survived an average oral dose of 3680 mg/kg.5

    Short-term studies

    Rabbit.  Three rabbits survived 17 consecutive daily feedings of
    disodium tartrate in an average dosage of 1150 mg/kg; whereas average
    dosages of 3680 mg/kg killed 3 out of 6 rabbits in 6 to 19 consecutive
    daily feedings.5

    Dog.  Tartaric acid was administered in daily oral doses of 990
    mg/kg to each of 4 dogs for 90-114 days.  Casts appeared in the urine
    of 3 dogs; the blood chemistry remained normal except in 1 dog in
    which azotaemia developed with death in 90 days.  Weight changes
    varied from a gain of 30% to a loss of 32%.7

    Long-term studies

    Rat.  Groups of 24 rats (12 of each sex) were fed diets containing
    0.1%, 0.5%, 0.8% and 1.2% of tartaric acid for a period of 2 years.  A
    group of 48 rats served as controls.  No significant toxic effects
    were observed in any of the groups as determined by growth rate (for
    the first year), mortality throughout the experiment, and gross and
    microscopic findings at the end of the 2-year, period.  An
    exceptionally thorough microscopic pathological examination was
    carried out.8

    Comments on experimental studies reported

    In the Seventh Report of the Joint FAO/WHO Expert Committee on Food
    Additives (page 63), evaluations of sodium tartrate and potassium
    sodium tartrate are presented with the comment that the evaluation of
    tartaric acid in the Sixth Report may have been unduly restrictive in
    comparison with that of the tartrates.  The present re-evaluation is
    made after reconsideration of the data used previously in the light of
    this comment.

    Evaluation

    Level causing no significant toxicological effect in the rat

    1.2% (= 12 000 ppm) in the diet, equivalent to 600 mg/kg body-weight
    per day.

    Estimate of acceptable daily intakes for man

    The total daily intake of tartrate should not exceed:

                                         mg/kg body-weight

             Unconditional acceptance           0-6
             Conditional acceptance             6-20

    References

    1.  Underhill, F. P., Peterman, F. I. & Krause, A. G. (1931) J.
    Pharmacol. exp. Ther., 43, 351

    2.  Underhill, F. P., Leonard, C. S., Gross, E. G. & Joleski, T. C.
    (1931) J. Pharmacol. exp. Ther., 43, 359

    3.  Underhill. F. P., Peterman, F. I., JoleskI, T. C. & Leonard, C. S.
    (1931) J. Pharmacol. exp. Ther., 43, 381

    4.  Finkle, P. (1933) J. biol. Chem., 100, 349

    5.  Locke, A., Locke, R. B., Schlesinger, H. & Carr, H. (1942) J.
    Amer. pharm. Ass., sci. Ed., 31, 12

    6.  Sourkes, T. L. & Koppanyi, T. (1950) J. Amer. pharm. Ass., sci.
    Ed., 34, 275

    7. Krop, S. & Gold, H. (1945) J. Amer. pharm. Ass., sci. Ed., 34, 86

    8. Fitzhugh, O. G. & Nelson, A. A. (1947) J. Amer. pharm. Ass., sci.
    Ed., 36, 217
    

    See Also:
       Toxicological Abbreviations
       Tartaric acid (ICSC)