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
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.
DIACETYL TARTARIC AND FATTY ACID ESTERS OF GLYCEROL
These emulsifiers have been evaluated for acceptable daily intake
by the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
Ref. No. 13) in 1966.
The previously published monograph has been revised and is
reproduced in its entirety below.
Six male rats were fed 0.53 to 0.81 g/kg bw 14C-acetyltartaric
acid ester of mono- and diglycerides (labelled in the two carboxyl
groups of tartaric acid) as an oily solution. Within 24 hours only 26
to 31% of the radioactivity was absorbed. Twelve to 20% of the
radioactivity was eliminated as 14CO2 and 8 to 13% was excreted in
the urine; 2% was found in the carcass (Lang & Schmidt, 1965). The
analysis of the depot fat of dogs fed up to 20% of the substance for
22 months showed no traces of either free or a fat soluble derivative
of tartaric acid (Koppanyi & Dardin, 1950). The digestibility
coefficient was over 90% of the substance or about the same as that of
lard (Koppanyi & Dardin, 1950). In an aqueous medium diacetyl tartaric
ester of mono- and diglycerides was hydrolyzed spontaneously to mono-
and diglycerides and acetylated tartaric acid, the hydrolysis being
somewhat accelerated by pancreatic lipase (Lang & Schmidt, 1965).
There was some evidence that diacetyltartaric acid was also hydrolyzed
in the body (Sourkes & Koppanyi, 1950).
No acute toxic effects at a practicable dose level have been
demonstrated. Rats and rabbits tolerated intragastric doses of 30 g/kg
bw and dogs 27 g/kg bw without any adverse effects. No diarrhoea was
noted and autopsied animals showed no pathological changes.
Histological examination of liver and kidneys of animals killed 10
days after the administration of the substance showed no abnormalities
(Koppanyi & Dardin, 1950).
Thirteen dogs each received daily i.v. injections of 0.5%
suspensions of the substance in isotonic glucose at a dose rate of 40
to 50 ml/kg bw for a total of up to 30 infusions. A fall in
haemoglobin concentration occurred in 11 dogs and a pleural effusion
in six. Groups of two three-year-old dogs were fed diets containing 0,
5, 10 and 20% of diacetyl tartaric esters of mono- and diglycerides
for 25-1/2 months. No specific effects attributable to the test
substance were seen (Hartwig et al., 1962).
Groups of eight rats were fed 0, 5, 10 and 20% diacetyltartaric
esters of mono- and diglycerides, another two groups were fed 50%
white bread (bread control group) and 50% bread which was baked with
the addition of 10% of the emulsifier in terms of flour weight (bread
test group) for two years. No difference was found between the groups
regarding body weight, external appearance, liver and kidney weights
and mortality rate. Autopsies and histological examination of the
major organs showed no changes attributable to the test substance. A
second generation was maintained on similar regimes for 22 months.
There was no difference between the groups regarding body weight,
mortality and results of gross and histological examination. All
litters were normal (Koppanyi & Dardin, 1950).
Diacetyltartaric acid is not a natural constituent for the diet,
and its low rate of spontaneous hydrolysis possibly allows the
absorption of some unhydrolyzed compound. The experimental results
show that the ester has a very low toxicity when given orally and that
the acetylated tartaric acid moiety is absorbed only to a small
extent. Evaluation is based on the available toxicological information
and the results of the biochemical and metabolic studies.
Level causing no toxicological effect
Rat: 100 000 ppm (10%) in the diet equivalent to 5000 mg/kg bw.
Estimate of acceptable daily intakes for man
0-50* mg/kg bw.
Hartwig, Q. L., Singleton, W. S. & Cotlar, A. M. (1962) Toxicol. Appl.
Pharmacol. 4, 107
Koppanyi, T. & Dardin, V. (1950) Unpublished report to WHO
Lang, K. & Schmidt, B. (1967) Unpublished report to WHO
Sourkes, T. L. & Kappanyi, T. (1950) J. Amer. Pharm. Assoc., sci. Ed.,
* The total food additive intake of tartaric acid should not exceed
30 mg/kg bw per day.