Toxicological evaluation of some food
additives including anticaking agents,
antimicrobials, antioxidants, emulsifiers
and thickening agents
WHO FOOD ADDITIVES SERIES NO. 5
The evaluations contained in this publication
were prepared by the Joint FAO/WHO Expert
Committee on Food Additives which met in Geneva,
25 June - 4 July 19731
World Health Organization
Geneva
1974
1 Seventeenth Report of the Joint FAO/WHO Expert Committee on
Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 539;
FAO Nutrition Meetings Report Series, 1974, No. 53.
STEARYL CITRATE
Explanation
This substance has been evaluated for acceptable daily intake by
the Joint FAO/WHO Expert Committee on Food additives (see Annex 1,
Ref. No. 20) in 1969.
Since the previous evaluation, additional data have become
available and are summarized and discussed in the following monograph.
The previously published monograph has been revised and is reproduced
in its entirety below.
BIOLOGICAL DATA
BIOCHEMICAL ASPECTS
Stearyl citrate upon enzymic hydrolysis could give rise to
stearyl alcohol, and citric acid. There is evidence that this
hydrolysis readily occurs in the dog, and to a lesser extent in the
rat (Calbert, C. E. et al., 1951).
The effect of stearyl citrate on fat absorption and digestibility
and the digestibility of the compound itself were studied in rats and
dogs. Four groups of eight to 10 female rats were given 15% margarine
in the diet with or without addition of stearyl citrate at a rate of
5% of margarine. Fat absorption after four and six hours was
unaffected by the presence of the additive. Three groups of nine to
10 female rats were fed 0.13%, 2.5% and 10% stearyl citrate, margarine
being added to bring the total level of fat plus test substance to 25%
of the diet. Digestibility of fat was determined by eight-day balance
studies; the normal value of 95% was reduced respectively to 77% and
71% at 2.5% and 10% level. The digestibility of stearyl citrate was
55%, 6% and 20%, at 0.13%, 2.5% and 20% level respectively.
Digestibility of fat in dogs was studied over 12 days in two groups of
three, one as control, the other with 3% stearyl citrate in the diet.
Normal fat digestibility was 95% in the controls and 80% in the test
diet, the digestibility of stearyl citrate was 52% at 3% level
(Calbert et al., 1951).
TOXICOLOGICAL STUDIES
Acute toxicity
Animal Route LD50 mg/kg bw Reference
Rat oral > 5 400 Deuel et al., 1951
Dog oral > 5 000 Deuel et al., 1951
Short-term studies
Rat
Groups of 10 male and 10 female rats were fed diets containing
0%, 1.3%, 2.5%, 5% and 10% stearyl citrate for six weeks. There was no
demonstrable effect on growth (Deuel et al., 1951). In another
experiment four groups, of 19 male and female weanling rats each, were
fed for 10 weeks on a diet containing unheated margarine, margarine
heated continuously for eight hours to 205°C, 0.86% stearyl citrate in
similarly treated margarine and 0.68% stearyl citrate potato chips
fried in margarine with this additive. Growth rates were identical in
all four groups (Deuel et al., 1951).
Three groups of 14 to 15 weanling rats were kept for 10 weeks on
a diet containing 0%, 1.9% and 9.5% stearyl citrate, mated when 13
weeks old and continued on the same diet throughout pregnancy and
lactation. The second generation was weaned at three weeks and treated
like the parent generation. Studies were continued to the weaning of
the fifth generation. No deleterious effects on litter size,
fertility, lactation and body weight on growth of progeny were noted
(Deuel et al., 1951).
Rabbit
Groups of eight rabbits received diets containing 0%, 2% and 10%
stearyl citrate for six weeks. There was no demonstrable effect on
growth except for one animal which lost weight during the early test
when it failed to eat; this rabbit began to regain its weight during
the last week of the test. A complete histopathological examination
made on all eight rabbits of the control and 10% stearyl citrate group
showed no pathological findings (Deuel et al., 1951).
Dog
Two groups of four animals each were fed 0% and 3% stearyl
citrate in the diet for 12 weeks. No difference in weight gain was
noted between controls and treated animals at four, eight and 12
weeks. Haemoglobin levels at the end of the period were practically
identical for the two groups. Histopathological examination of the
livers and kidneys showed no pathological findings (Deuel et al.,
1951).
Long-term studies
Rat
Groups of 10 male and 10 female rats were fed for two years on
diets containing 0%, 0.5%, 2% and 10% stearyl citrate. From 55% to 65%
survived in the test groups compared with 44% in the control group. No
variations in weight gains were noted between test animals and
controls. A complete histopathological examination was carried out in
the animals which received 10% stearyl citrate. No specific
pathological findings were seen; there were metastatic calcification
and tumours not significantly different from the controls (Deuel et
al., 1951).
Comments:
Addition of this material to the diet reduces absorption of fat
in the rat and to a lesser extent in the dog. The 10% level appears to
provide no adverse effects in the long-term studies in the rat. The
further work desirable is adequate short-term studies in two species
(one a non-rodent mammalian species); some of these studies should use
combinations with hard fats. Emphasis should be placed on evaluation
of kidney function.
EVALUATION
Level causing no toxicological effect
Rat: 100 000 ppm (10%) in the diet equivalent to 5000 mg/kg bw
per day.
Estimate of acceptable daily intake for man
0-50 mg/kg bw.
FURTHER WORK OR INFORMATION
Desirable
Short-term studies in two species (one a non-rodent mammalian
species); some of these studies should use combinations with hard
fats. Emphasis should be placed on evaluation of kidney function.
REFERENCES
Calbert, C. E. et al. (1951) Food Res., 16, 294
Deuel, H. J. jr et al. (1951) Food Res., 16, 258
See Also:
Toxicological Abbreviations
Stearyl citrate (FAO Nutrition Meetings Report Series 46a)
STEARYL CITRATE (JECFA Evaluation)