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.


    PHOSPHATED DISTARCH PHOSPHATE

    Biological Data

    These modified starches are prepared by the combined use of sodium
    tripolyphosphate and sodium trimetaphosphate which results in
    cross-linking and esterification of starch chains. The overall extent
    of modification is still small, the residual phosphate being of the
    order of 0.4 per cent. P.

    Biochemical aspects

    The in vitro digestibility of this modified starch by pancreatic
    amylase was somewhat reduced compared with normal unmodified starch
    (Kohn & Kay 1963a). In vivo digestibility was examined in groups of
    10 male rats fed for 10 days 5 g basal diet supplemented by 1 g, 2 g,
    or 4 g unmodified or modified starch. Weight gains were identical for
    both types tested at all three levels of supplementation. No unusual
    behavioural reactions were observed (Kohn & Kay 1963b).

    Acute toxicity

    None available.

    Short-term studies

    Rat. Groups of 10 male and 10 female rats were fed on a diet
    containing 10 per cent. rising to 35 per cent. of phosphated distarch
    phosphate for a total of 60 days. Female rats showed a consistent
    reduced weight gain throughout the test. Although four test and two
    control animals died during the test these incidents were regarded as
    unrelated to the test substance. All animals behaved normally.
    Haematological examination and urinalysis were normal and comparable
    in the various groups. The absolute liver weights of male rats were
    lower for the test group than for controls and the absolute kidney
    weight were lower for both sexes but these findings were not
    associated with any gross or histopathological changes. (Kohn et al.,
    1964).

    Groups of 25 male and 25 female rats were fed diets containing 0.2 per
    cent., 1.0 per cent. and 5.0 per cent. modified or unmodified starch
    for 90 days. Eleven controls and three test animals died from
    intercurrent disease. There were no obvious gross or histopathological
    changes attributable to the test substance. Organ weights and
    haematological examination (days 45 and 90) were normal in both
    groups. Pooled urinalysis was comparable for all three groups. (Kohn
    et al., 1964).

    Dog. Groups of three male and three female beagles were given daily
    for 90 days gelatine capsules containing 50, 250 and 1250 mg modified
    starch/kg body weight. No adverse effects were observed as judged by
    behaviour, body weight changes, mortality, haematological studies,

    blood chemistry, urinalysis, liver function tests, organ weights,
    gross and histopathological findings (Cervenka & Kay, 1963b).

    Long-term studies

    None available.

    Comments

    Although the extent of the modification is small there is some
    evidence of reduced in vitro digestibility by enzymes. The levels
    tested in rats and dogs represent 3.5 per cent. - 5 per cent. of the
    diet and did not attain an effect level. Further metabolic studies
    preferably in man are desirable. Evaluation is based on the available
    short-term studies but further 90-day studies in two species at levels
    higher than those studied hitherto are desirable.

    EVALUATION

    Level causing no toxicological effect in the rat

    Five per cent. (= 50 000 ppm) in the diet equivalent to 2500 mg/kg
    body weight/day.

    Estimate of acceptable daily intake for man

    Unconditional acceptance                mg/kg body weight

                                                 0 - 25a

    REFERENCES

    Cervenka, H. & Kay, J, H. (1963) Unpublished reportb submitted by
    Corn Products Co.

    Kohn F. E. & Kay, J. H. (1963a) Unpublished reportb submitted by
    Corn Products Co.

    Kohn, F. E. & Kay, J. H. (1963b) Unpublished reportb submitted by
    Corn Products Co.

    Kohn, F. E. Kay, J. H. & Calandra, J. C. (1964a) Unpublished reportb
    submitted by Corn Products Co.

    Kohn, F. E. & Kay, J. H. (1964b) Unpublished reportb submitted by
    Corn Products Co.

                   
    a Includes distarch phosphate prepared using trimetaphosphate or
    phosphated distarch phosphate or the sum of both. Subject to limits of
    phosphorous load given in the seventh report of the Joint FAO/WHO
    Expert Committee on Food Additives, Wld. HIth Org. techn. Rep. Ser.,
    281, p.31.
    b By Industrial Bio-test Laboratories.
    

    See Also:
       Toxicological Abbreviations
       Phosphated distarch phosphate (WHO Food Additives Series 1)
       Phosphated distarch phosphate (WHO Food Additives Series 5)
       Phosphated distarch phosphate (WHO Food Additives Series 17)
       PHOSPHATED DISTARCH PHOSPHATE (JECFA Evaluation)