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.
ACETYLATED DISTARCH GLYCEROL
Explanation
Modification is carried out with epichlorhydrin to a maximum of
0.3% and acetic anhydride to a maximum of 8%. The amount of acetyl
groups introduced does not exceed 2.5%. Further treatment, such as
bleaching is often carried out.
BIOLOGICAL DATA
BIOCHEMICAL ASPECTS
The in vitro digestibility of acetylated distarch glycerol
(0.3 per epichlorhydrin, 1.2 or 2.5% acetyl content) varies with the
acetyl content but is not affected by cross-linkage. At 1.2%
acetylation some 82% of the modified starch are digestible, at 2.5%
only 68.5% are hydrolyzed enzymatically (Kruger, 1970). The caloric
value was determined by reference to a dose-response curve established
in groups of 10 male rats given a basic diet with graded supplements
of 0, 0.75 g, 1.5 g, 3.0 g and 4.5 g sucrose equivalent to 0, 3, 6, 12
and 18 calories per day. Starches modified by the use of 0.1%
epichlorhydrin + 5.5% acetic anhydride and 0.3% epichlorhydrin + 5.5%
acetic anhydride were tested against native starch at levels of
supplementation of 1.5 g and 3.0 g per day for 28 days. Weight gain on
modified starch supplement was slightly reduced compared with than on
unmodified starch. All rats remained normally active and healthy. The
caloric estimates were similar for both levels of epichlorhydrin
treatment (Oser, 1961).
TOXICOLOGICAL STUDIES
Short-term studies
Rat
Groups of 15 male and 15 female rats were fed for 90 days on
diets containing 50% either native or modified starch (0.3%
epichlorhydrin + 10.5% acetic anhydride). The growth rate of male rats
was significantly lower compared with controls on unmodified starch.
The full and empty caecal weights of both male and female rats in the
test groups were significantly greater than in controls. Haematology,
blood chemistry, urinalysis, organ weights and gross as well as
histological examination were normal (Oser, 1964).
Comments:
The feeding studies with rats show that the modified starch is
well utilized. The available evidence for the group of modified
starches considered suggest that caecal enlargement without associated
histopathological changes is without toxicological significance. The
short-term rat study shows no other significant effects related to
treatment, the observed growth depression being the obvious result of
the high dietary level used. No long-term study is available but the
collateral evidence from starch acetate and distarch glycerol
indicates that neither of these modifications singly applied cause any
adverse effects.
EVALUATION
Estimate of acceptable daily intake for man
Not limited.*
REFERENCES
Kruger, L. (1970) Unpublished reports Nos 405 and 406 submitted by
National Starch and Chemical Corporation
Oser, M. (1961) Unpublished report of Food and Drug Research
Laboratories Inc. No. 81774, submitted by National Starch and
Chemical Corporation
Oser, B. L. (1964) Unpublished report of Food and Drug Research
Laboratories Inc. No. 85554, submitted by National Starch and
Chemical Corporation
* See relevant paragraph in the seventeenth report, pages 10-11.