WORLD HEALTH ORGANIZATION
Toxicological evaluation of some food colours, thickening
agents, and certain other substancse
WHO FOOD ADDITIVES SERIES NO. 8
The evaluations contained in this publication were prepared
by the Joint FAO/WHO Expert Committee on Food Additives which
met in Geneva, 14-23 April 19751
World Health Organization, Geneva 1975
1 Nineteenth Report of the Joint FAO/WHO Expert Committee on Food
Additives, Wld Hlth Org. techn. Rep. Ser., 1975, No. 576;
FAO Nutrition Meetings Report Series, 1975, No. 55.
The monographs contained in the present volume are
also issued by the Food and Agriculture Organization
of the United Nations, Rome, as
FAO Nutrition Meetings Report Series, No. 55A
ISBN 92 4 166008 2
(C) FAO and WHO 1975
Non-amidated pectin was evaluated for acceptable daily intake for
man by the Joint FAO/WHO Expert Committee on Food Additives (see Annex
1, Refs No. 20 and No. 33) in 1969 and 1973. Amidated pectin was
evaluated in 1973 and 1974 (see Annex 1, Refs No. 33 and No. 35).
Since the previous evaluation of amidated pectin, additional data
have become available and are summarized and discussed in the
following monograph addendum.
Four groups of 10 male and 10 female rats were fed on diets
containing 0%, 5%, 10%, or 15% pectin (21% amidated) for 90 days. No
adverse effects were noted on general condition, behaviour and
survival. Growth was slightly decreased at the 15% level and this
finding was also noted in a range finding test using 20% pectin, in
the diet. Some decrease in growth occurred inconsistently also at the
10% dietary level. Food intake and food efficiency were not affected
at any level. Haematological parameters showed no significant
treatment related changes. Total serum protein and albumin were
reduced at the 15% level but the other clinical biochemical parameters
and urinalysis were essentially normal. Caecal weights were increased
at all levels but in a dose-related manner. These findings are
reminiscent of what is seen when high amounts of starch, modified
starch or certain other carbohydrates are fed. Gross and
histopathology were normal but a slight degree of hyperkeratosis of
the fore-stomach in some males was seen at the 10% and 15% level but
is probably not of toxicological significance (Til et al., 1972).
Groups of 20 male weanling Wistar rats were fed diets of purina
laboratory meal to which was added L.M. pectin (approximately 18%
amidated) or pectin, N.F. at 10% of the diet. Control diets contained
10% alphacellulose (alphacel). The rats were fed for two years. The
diets were made isocaloric by supplementing the alphacel with dextrose
assuming a caloric equivalent for pectin of 0.6187 cal/g. Mortality
did not vary significantly between groups. Body weights for the pectin
fed groups were similar but significantly less than that of the
control animals. A comparison of grams of diet/kg body weight showed a
slightly greater food utilization for the pectin fed groups. The
controls, however, consumed more food and gained more weight. There
was no significant difference in average organ to body weight ratios
for adrenal, heart, kidney, liver and spleen. The testes/body of the
pectin fed groups did not differ from each other but both were
significantly larger than those of the control group. Blood chemistry,
SGOT and SPGT done at sacrifice showed no abnormalities in the pectin
groups. Gross examination at necropsy showed no unusual findings. Two
tumours were noted in the control group and one in the amidated pectin
group. All gross lesions and adrenal, heart, kidney, liver, lung,
spleen and testes were examined histologically. No compound related
effects were observed (Palmer & Jones, 1974; Abdul-Haj & Palmer,
Wistar rats of the Center for Investigation and Medical Research
at Marseille strain were administered 100 mg/kg body weight of 18.4%
amidated pectin, daily in the synthetic diet of Lacassagne MABI.
Feeding was ad lib. Group of 20 males and 20 females housed five to
a cage were used. Controls consisted of an identical group of rats fed
the basic synthetic diet. At this level of pectin in the diet there
appeared to be no effects on growth and body weights of fed animals as
compared to historic controls. Also, there appeared to be no effects
on the serum of fed rats. Since many of the experimental details are
lacking it is difficult to reconstruct the complete design of the
study. It is clear, however, that tissues from 20 males and 20 females
sacrificed at 24 months were studied histologically. Rats dying prior
to termination of the study were also said to have been examined
microscopically, however, no mention of such animals is made in the
detailed pathology. The histopathology revealed no adverse effects on
the stomachs or testes of fed males. It should be noted that these
were very small rats. Only one male reached 640 g the remainder ranged
from 210-420 g with seven of the rats weighing 270 g or less. The
weight of the females at sacrifice was similar to the males. A first
generation produced by mating 10 animals produced a total of 21
offspring and a second generation produced by mating five animals
resulted in only 18 offspring (Mosinger, 1974).
There are three studies with amidated pectin available for
evaluation. Neither of the two long-term studies was considered
adequate. There were no major adverse findings noted.
Level causing no toxicological effect in the rat
5% in the rat equivalent to 2500 mg/kg body weight.
Estimate of acceptable daily intake for man
0-25 mg/kg body weight.*
FURTHER WORK OR INFORMATION
Required by 1980.
(1) Adequate reproduction and embryotoxicity studies including
teratology studies in rats.
(2) Adequate long-term study in a rodent species.
Abdul-Haj & Palmer, G. H. (1974) Two-year pectin feeding study:
histopathological studies. Unpublished report from Sunkist
Growers, Inc. submitted to the World Health Organization by
Sunkist Growers, Inc.
Mosinger, M. (1974) Experimentation d'epreuve concernant les effets de
l'administration orale prolongée du produit pectine L.M. NST de
la Societé Unipectine SA. Unpublished report from the "Centre
d'explorations et de recherches medicales", Marseille, submitted
to the World Health Organization by the International Pectin
Til, H. P., Seinen, W. & de Groot, A. P. (1972) Sub-chronic (90-day)
toxicity study with two samples of pectin (Mélange A2 and C2)
in rats. Unpublished report from Centraal Instituut voor
Voedingsonderzoek TNO submitted to the World Health Organization
by the Inst. Eur. des Ind. de la Pectine
Palmer, G. H. & Jones, T. R. (1974) Two-year pectin feeding study.
Unpublished report from Sunkist Growers, Inc. submitted to the
World Health Organization by Sunkist Growers, Inc.