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.
CITRIC 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.
In vitro hydrolysis by pancreatic lipase and liver esterase
produced nearly the same yield of citric acid in the same two-hour
period as spontaneous hydrolysis at pH 7.5 to 8.5 (Lang, 1964). The
existence of a true citric acid ester bond in this compound has been
questioned (Schade, 1963).
The digestibility of this compound was compared with a physical
mixture of its constituents and with lard in groups of 20 male and
female rats on a calorie-restricted basal diet, for 10 days. The
dietary levels of the ester and mixture were 23.1 and 37.5%; and of
lard, 16.7 and 35.5%. These were calculated to give isocaloric diets
at two levels of caloric supplementation above the control level.
Faecal fat estimation and body fatty acid distribution showed that the
ester was completely digestible, although the absorption of the ester
or its component mixture was about 50% that of lard (Huntingdon,
In two groups of five male and five female weanling rats fed
diets containing 0 and 20% of ester for seven days, food intake and
body weight maintenance were the same in both groups, and the
digestibility of the ester was calculated to be 99% (Rosner, 1959).
No data are available.
In the 10-day study quoted above (under Biochemical aspects),
gross and microscopic examination of major organs of the test animals
revealed only dystrophic lower-nephron calcification in animals
receiving the highest levels of the ester or the component mixture. No
effect was seen at the 23.1% levels (Huntingdon, 1966).
No data are available.
This substance is hydrolyzed completely in the intestinal tract
into components which are normal constituents of the diet. Evaluation
is based on knowledge of the metabolic fate and lack of toxicity of
the constituent citric acid and fatty acid esters of glycerol.
Estimate of acceptable daily intake for man
Huntingdon Research Centre (1966) Unpublished report submitted by
Lang, K. (1964) Unpublished report submitted by Emulsion A/S
Rosner, L. (1959) Unpublished report by Laboratory of Vitamin
Schade, H. (1963) Unpublished report submitted by Emulsion A/S
*1 See relevant paragraph in the seventeenth report (pages 10-11).
*2 As sum of glycerol esters of fatty acids and acetic, citric,
lactic and tartaric acids, provided that the total food additive
intake of tartaric acid does not exceed 30 mg/kg.