WORLD HEALTH ORGANIZATION

    WHO Food Additives Series 1972, No. 1




    TOXICOLOGICAL EVALUATION OF SOME 
    ENZYMES, MODIFIED STARCHES AND 
    CERTAIN OTHER SUBSTANCES




    The evaluations contained in this publication were prepared by the
    Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
    16-24 June 19711





    World Health Organization

    Geneva

    1972





                   

    1 Fifteenth Report of the Joint FAO/WHO Expert Committee on Food
    Additives, Wld Hlth Org. techn. Rep. Ser., 1972, No. 488; FAO
    Nutrition Meetings Report Series, 1972, No. 50.

    The monographs contained in the present volume are also issued by the
    Food and Agriculture Organization of the United Nations, Rome, as FAO
    Nutrition Meetings Report Series, No. 50A

    (c) FAO and WHO 1972


    ACETYLATED DISTARCH GLYCEROL

    Modification is carried out with epichlorhydrin to a maximum of 0.3
    per cent. and acetic anhydride to a maximum of 8 per cent.  The amount
    of acetyl groups introduced does not exceed 2.5 per cent.  Further
    treatment, such as bleaching is often carried out.

    Biological data

    Biochemical aspects

    The in vitro digestibility of acetylated distarch glycerol (0.3 per
    epichlorhydrin, 1.2 or 2.5 per cent. acetyl content) varies with the
    acetyl content but is not affected by cross-linkage.  At 1.2 per cent.
    acetylation some 82 per cent. of the modified starch are digestible,
    at 2.5 per cent. only 68.5 per cent. are hydrolysed enzymatically
    (Kruger, 1970).  The caloric value was determined by reference to a
    dose-response curve established in groups of 10 male rats given a
    basic diet with graded supplements of 0, 0.75 g, 1.5 g, 3.0 g and 4.5
    g sucrose equivalent to 0, 3, 6, 12 and 18 calories per day.  Starches
    modified by the use of 0.1 per cent. epichlorhydrin + 5.5 per cent.
    acetic anhydride and. 0.3 per cent. epichlorhydrin + 5.5 per cent.
    acetic anhydride were tested against native starch at levels of
    supplementation of 1.5 g and 3.0 g per day for 28 days.  Weight gain
    on modified starch supplement was slightly reduced compared with that
    on unmodified starch.  All rats remained normally active and healthy.
    The caloric estimates were similar for both levels of epichlorhydrin
    treatment (Oser, 1961).

    Short-term studies

    Rat

    Groups of 15 male and 15 female rats were fed for 90 days on diets
    containing 50 per cent. either native or modified starch (0.3 per
    cent. epichlorhydrin + 10.5 per cent. acetic anhydride).  The growth
    rate of male rats was significantly lower compared with controls on
    unmodified starch.  The full and empty caecal weights of both male and
    female rats in the test groups were significantly greater than in
    controls.  Haematology, blood chemistry, urinalysis, organ weights and
    gross as well as histological examination were normal (Oser, 1964).

    Comments

    The feeding studies with rats show that the modified starch is well
    utilized.  The available evidence for the group of modified starches
    considered suggests that caecal enlargement without associated
    histopathological changes is of little toxicological significance. 
    The short-term rat study shows no other significant effects related to
    treatment, the observed growth depression being the obvious result of
    the only high dietary level used.  No long-term study is available but

    the collateral evidence from starch acetate and distarch glycerol
    indicates that neither of the modifications singly applied cause any
    adverse effects.

    EVALUATION

    Temporarily not limited.*

    Further work required by 1973

    Histological reports to complete the 2-year and reproduction rat
    studies on starch acetate.

    Histological reports to complete the 2-year and reproduction rat
    studies on hydroxypropyl distarch glycerol.

    REFERENCES

    Kruger, L. (1970) Unpublished reports Nos 405 and 406 submitted by
    National Starch & Chemical Co.

    Oser, M. (1961) Unpublished report of Food and Drug Research
    Laboratories Inc. No. 81774, submitted by the National Starch and
    Chemical Co.

    Oser, B. L. (1964) Unpublished report of Food and Drug Research
    Laboratories Inc. No. 85554, submitted by the National Starch and
    Chemical Co.

                   

    * Except for good manufacturing practice.
    

    See Also:
       Toxicological Abbreviations
       Acetylated distarch glycerol  (FAO Nutrition Meetings Report Series 46a)
       Acetylated distarch glycerol (WHO Food Additives Series 5)
       Acetylated distarch glycerol (WHO Food Additives Series 17)
       ACETYLATED DISTARCH GLYCEROL (JECFA Evaluation)