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    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


    ESTERS OF GLYCEROL AND THERMALLY OXIDIZED SOY BEAN FATTY ACIDS

    Biological data

    Biochemical aspects

    Groups of 5 male and 5 female rats received in their diet either 20
    per cent. soya bean oil or thermally oxidized material.  Highly
    modified material reduced the absorption of dietary fat in proportion
    to the degree of modification introduced.  Modified material delays
    absorption of oil from the gastrointestinal tract as measured by
    residuals found in the gut.  Similar delaying effects have been
    demonstrated on the presence of chylomicrons and fat in the intestinal
    lymph fluid.  The passage of intestinal contents is delayed if
    modified oil is administered.  Compared with normal oil there is an
    early increase followed by only slight decrease in bile flow following
    oral administration of modified oil.  Intraperitoneal administration
    of modified oil increases the diuretic effect of normal soya bean oil
    when given intraperitoneally.  Study of the liver function after 8
    weeks feeding of modified oil showed retention of the
    bromosulphophthalein used as indicator compared with normal oil
    (Kieckebusch et al., 1962).  The in vitro effect of modified oil on
    the kinetics of various cellular enzyme systems showed generally no
    inhibition of oxidative metabolism (Kieckebusch et al., 1962).

    Acute toxicity

    None available.

    Short-term studies

    Rat

    Groups of 20 male and 20 female rats received over 12-16 weeks in
    their diet either 20 per cent. untreated soy bean oil of 5 per cent.
    variously modified soy bean oil plus 15 per cent. olive oil or 2.5 per
    cent. modified oil plus 17.5 per cent. olive oil.  Only highly
    modified oils showed significant reduction in growth, food intake and
    increased mortality.  No definite effect was noted at the 2.5 per
    cent. level.  Motor activity of animals on high doses of highly
    modified oil was increased compared with controls.  The weights of
    major organs were similarly increased for the groups on the more
    highly modified oils.  Gross and histopathology showed some
    pathological changes in the thyroid and kidney of the group receiving
    the most highly modified material (Kieckebusch et al., 1962).

    Three groups each of 6 rats were treated for 17 weeks with an
    esterified product at 0, 0.084 and 0.84 per cent. of their basic diet.
    There was no significant effect on weight gain and macroscopic
    appearance.  Liver and stomach were examined histologically and found
    to be normal (Dam, 1952).

    Two groups of 9 male rats received for 36 weeks feeds containing
    margarine made with an esterified product at 0.3 and 3 per cent.
    levels.  No controls were used.  No weight differences or gross
    pathological changes were noted.  The histology of kidneys, liver and
    small intestine was normal (Aaes-Jorgensen et al., 1954).

    Pig

    Four groups of 4 female pigs received an esterified product for 98
    days at dietary levels of 0, 0.4, 2 and 10 per cent.  No significant
    effects were discovered on growth rate, food consumption, blood
    picture, liver and kidney function, serum chemistry, organ weights,
    gross and histopathology due to administration of the test compound
    (Gyrd-Hansen & Rasmussen, 1968).

    Long-term studies

    Rat

    A three generation study was performed using an average level of 15
    per cent. esterified product in the diet.  The P generation (57
    females, 15 males) was observed for at least 24 months.  Growth,
    body-weight gain and appearance were similar to controls (7 male, 7
    female) receiving 15 per cent. soy bean oil.  Five animals in the test
    group developed tumours but none in the control group.  There were 16
    survivors in the test group and 2 in the control group.

    The F1 generation (37 male, 37 female) was also observed for 24
    months.  Thirty-seven males and females received soya bean oil as
    controls.  Twenty-four test and 10 control animals survived 2 years.
    Two test-animals and 3 controls developed tumours.  The F2 generation
    (57 female, 27 male) was observed for over 2 years.  Seventy males and
    females acted as controls on soya bean oil.  Four test and 19 control
    animals survived 24 months.  No animal in the test group but 3 in the
    control group developed tumours.  Both the F1 and F2 generation
    showed no significant differences from controls as regards growth,
    body-weight gain, gross and histopathology.

    In another experiment an esterified product was fed orally at the rate
    of 3 g/day and injected s.c. to 29 rats at 1 ml weekly for 5 months
    and 2 ml bi-weekly for a further 3 months.  Animals were observed for
    27 months.  No tumours developed.  A control series of 30 rats treated
    similarly with oral esterified product and injected s.c. with refined
    soya bean oil showed 4 tumours after 24 months observation, none at
    the site of injection.  The F1 test generation (9 male, 9 female)
    received 3 g esterified product orally and 1 ml i.p. for 8 weeks,
    followed by a further 1 ml i.p. for 4 months.  After 11 months 6
    survived without any tumours being noted.  The control group (14 male,
    4 female) received 1 ml soya bean oil s.c. for 5 months and 2 ml s.c.
    for 3 months.  During 29 months observation, 1 rat developed a tumour
    at the site of injection (Harmsen, 1959; 1960, 1961).

    Comments

    Oxidized and heated fats have been shown to produce toxic symptoms
    when fed in large amounts to animals but the effects are not readily
    correlated with the physical characteristics or the various polymeric
    and peroxide-type of compounds formed during this treatment.  The
    significance of many of the observed changes is doubtful when
    assessing the hazard to man from ingestion of minute amounts of these
    compounds.  The specific compound studied is produced by thermal
    oxidation and steaming.  Short-term studies in two species are
    available for evaluation, as well as an adequate, combined life-span
    and reproduction study in the rat.

    EVALUATION

    Level causing no significant toxicological effect in the rat

    Fifteen per cent. (150 000 ppm) in the diet equivalent to 7500 mg/kg
    body-weight/day.

    Estimate of acceptable daily intake for man     mg/kg body-weight

         Temporary acceptance                         0-75

    Further work required by 1974

    Life-span studies in a second species and more adequate work on the
    metabolism of these compounds.

    REFERENCES

    Aaes-Jorgensen, E., Punch, J. P., Engel, P. P. & Dam, H. (1954)
    Unpublished report supplied by Grindstedvaerket Laboratoriet

    Dam, H. (1952) Unpublished report submitted by Grindstedvaerket
    Laboratoriet

    Gyrd-Hansen, N. & Rasmussen, F. (1968) Fd. Cosmet. Toxicol.  6, 163

    Harmsen, H. (1959) Unpublished report submitted by Grindstedvaerket
    Laboratoriet

    Harmsen, H. (1960) Unpublished report submitted by Grindstedvaerket
    Laboratoriet

    Harmsen, H. (1961) Unpublished report submitted by Grindstedvaerket
    Laboratoriet

    Kieckebusch, K., Jahr, K., Czok, G., Griem, W., Bissler, K.-H.,
    Hammar, D. C.-H. & Lang, K. (1962) Fette, Seifen, Anstrichmittel, 64,
    1154
    


    See Also:
       Toxicological Abbreviations
       ESTERS OF GLYCEROL AND THERMALLY OXIDIZED SOY BEAN FATTY ACIDS (JECFA Evaluation)