INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
WORLD HEALTH ORGANIZATION
TOXICOLOGICAL EVALUATION OF SOME
FOOD COLOURS, EMULSIFIERS, STABILIZERS,
ANTI-CAKING AGENTS AND CERTAIN
FAO Nutrition Meetings Report Series
No. 46A WHO/FOOD ADD/70.36
The content of this document is the result of the deliberations of the
Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
27 May - 4 June 19691
Food and Agriculture Organization of the United Nations
World Health Organization
1 Thirteenth report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series, in press;
Wld Hlth Org. techn. Rep. Ser., in press.
Modification is carried out by propylene oxide at levels up to 25 per
cent. and the resultant starch is usually lightly oxidised, bleached
or acid modified after etherification. Substitution may amount to a
maximum of 4 ether linkages per 10 glucopyranose units if 25 per cent.
propylene oxide is used and 4-6 ether linkages per 100 glucopyranose
units if 5 per cent. propylene oxide is used.
In vitro digestibility by pancreatin was estimated by comparing the
amount of reducing material liberated with that formed from native
wheat starch. No significant difference could be detected between low
(1 in 10) and high (4 in 10) substituted starches compared with
unmodified starch (Kay & Calandra 1962). Caloric value could not be
estimated because of diarrhoea.
Animal Route LD50 Reference
mg/kg body weight
Rat oral >10 000 Hercules Powder Co.,
Application of powder or solutions produced mild irritation in
rabbits' eyes (Pallotta, 1959). The Schwartz Prophetic Patch Test on
210 human subjects using powdered high and low modified starch, as
well as native starch as control, showed no difference after 72 hours
initial exposure and no evidence of sensitization on 72 hour challenge
after 2 weeks (Majors & Ruben Koenig, 1959). The Repeat Insult Patch
Test in 23 human subjects showed no irritation after 9 twenty-four
hour exposures and no evidence of sensitization on 24 hour challenge
after 2 weeks (Ruben Koenig, 1959).
Rat. Groups of 10 male and 10 female rats were fed for 90 days diets
containing 0, 2 per cent., 5 per cent., 10 per cent. and 25 per cent.
of highly modified starch (25% propylene oxide) and 25 per cent.
unmodified wheat starch. No systemic toxicity was noted. There were no
adverse effects regarding mortality, urinalysis or haematology at any
level. There was slight reduction in growth rate at the highest
dietary level with lower food utilization and without an equivalent
increase in food consumption. Mild diarrhoea occurred at 25 per cent.
dietary level. No adverse effects occurred at any other level. At
autopsy there were no significant differences in the organ weight of
liver, kidney, spleen, gonad, heart or brain. The observed increased
ratios at 25 per cent. dietary level for liver/body weight and
kidney/body weight were due to the relatively lower body weight. Gross
and histological examination of all major tissues revealed no
abnormalities due to the feeding of highly modified starch (Kay &
Calandra, 1961). In another experiment groups of 10 male and 10 female
rats were fed for 90 days on diets containing 0, 5 per cent., 15 per
cent. and 45 per cent. of low modified starch (5 per cent, propylene
oxide). Haematological findings at 12 weeks were comparable for all
groups. Body weights did not differ significantly from controls but
were consistently lower in male rats only. Feed efficiency was similar
in all groups. Caecal enlargement was seen at the 15 per cent. and 45
per cent. dietary levels. Diarrhoea occurred at the 45 per cent. level
and very slightly at the 15 per cent. level. No histological
abnormalities were detected in any major organs, which were due to the
test substance. The enlarged caeca showed no evidence of inflammation
or changes in the muscular coat (Feron at al., 1967).