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





    MICROBIAL RENNET

    Biological data

    Source

    This enzyme preparation is prepared from the species Mucor miehei.

    Acute toxicity

    None available.

    Short-term studies

    Rat

    Four groups of 25 male and 25 female rats received in their diet 0,
    0.1, 0.5 and 2.5 per cent. of microbial rennin (equivalent to 0, 100,
    500 and 2500 units/kg/day) for 1 year.  Appearance and behaviour was
    normal throughout the experiment.  Survival was comparable in all
    groups and the few deaths observed were unrelated to the
    administration of the test substance.  Mean body-weight and food
    consumption were similar to controls.  Haematology, blood chemistry
    and urinalysis showed nothing significant compared with controls.
    Relative organ weights, gross and histopathology showed nothing of
    note (Gesler, 1970).

    Dog

    Four groups of 5 male and 5 female beagles received by daily gavage 6
    times a week for 1 year either 0, 100, 500 or 2500 units/kg
    body-weight.  Apart from some vomiting early in the study and
    occasional vomiting in the highest test group there was no further
    difficulty in administration. Behaviour, appearance, food consumption
    and mean body-weight did not differ from controls.  Haematology, blood
    chemistry, blood coagulation studies and urinalysis revealed no
    changes due to the administration of the test substance.  Mean
    relative organ weights, gross and histopathology revealed no changes
    different from controls (Gesler, 1970a).

    Long-term studies

    None available.

    Comments

    Two studies extending over 1 year in the rat and dog are available for
    evaluation and do not reveal any adverse effects at levels up to 2.5
    per cent. in the diet of the rat.  They are not sufficiently long to
    reveal possible chronic effects although the levels used would have
    revealed any deleterious effects due to mycotoxins.  Because it is
    conceivable that undetected chronic effects could occur, further tests
    are necessary.

    EVALUATION

    Temporarily not limited.*

    Further work required by 1975

    Two-year study in rats.

    REFERENCES

    Gesler, R. M. (1970) Unpublished report submitted by Travenol
    Laboratories Inc.

    Gesler, R. M. (1970a) Unpublished report submitted by Travenol
    Laboratories Inc.

                   

    *Except for good manufacturing practice.
    

    See Also:
       Toxicological Abbreviations
       Microbial rennet (WHO Food Additives Series 1)
       Microbial rennet (WHO Food Additives Series 1)