INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
WORLD HEALTH ORGANIZATION
TOXICOLOGICAL EVALUATION OF SOME
FOOD COLOURS, ENZYMES, FLAVOUR
ENHANCERS, THICKENING AGENTS, AND
CERTAIN FOOD ADDITIVES
WHO FOOD ADDITIVES SERIES 6
The evaluations contained in this publication were prepared by the
Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
4-13 June 19741
World Health Organization Geneva 1975
1 Eighteenth Report of the Joint FAO/WHO Expert Committee on
Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 557.
FAO Nutrition Meetings Report Series, 1974, No. 54.
MICROBIAL CARBOHYDRASE* (Aspergillus niger)
This enzyme preparation has been evaluated for acceptable daily
intake by the Joint FAO/WHO Expert Committee on Food Additives (see
Annex 1, Ref. No. 27) in 1971.
Since the previous evaluation additional data have become
available and are summarized and discussed in the following monograph.
The previously published monograph has been expanded and is reproduced
in its entirety below.
No information available.
Studies on sensitizing effect was tested on 20 albino
guinea-pigs, 10 males and 10 females, of the Pirbright White
strain by a challenge injection of 0.05 ml intracutaneous two weeks
after 10 sensitizing injections of 1% Ultrazym 100 in a 2%
carboxymethylcellulose solution. The challenge injection produced a
more intense reaction than the sensitizing injections, indicating a
skin sensitizing activity (Sachsse, 1971).
A 70% suspension of Ultrazym 100 in a 2% carboxymethyl-cellulose
solution was dispersed over the shaved back of 12 RAC/f rats for 24
hours. Within 24 hours the rats of both dosage groups (1000 mg/kg and
2150 mg/kg) showed dyspnoea and lachrymation, but no skin irritation.
Recovering after five days, no substance-related gross organ changes
were observed at autopsy (Sachsse & Bathe, 1971b).
* This enzyme preparation is prepared from some varieties of
Animal Route (mg/kg bw) Reference
Mouse Oral >3 200 Hunt & Garvin, 1963
>4 000 Hunt & Garvin, 1971
>3 200 Willard & Garvin, 1963
4 000 Garvin et al., 1966
Rat Oral 10 000 Gray, 1960
31 600 Kay & Calandra, 1962
>3 200 Willard & Garvin, 1968
>4 000 Garvin et al., 1966
>10 000 Gray, 1960
Rabbit Oral >4 000 Garvin et al., 1966
Dog Oral >4 000 Garvin et al., 1966
Rat Oral 7 750 Sachsse & Bathe (1971a)
Four groups of 10 male rats received in their diet for 30 days
enzyme at 0, 0.5 and 5%. There were no adverse effects related to
treatment regarding growth, appearance, behaviour, survival, food
consumption, haematology, organ weights and gross pathology (Garvin et
Two groups of 10 male and 10 female rats received daily for 91
days in their diet either 0 or 5% enzyme. There was no difference from
controls regarding appearance, behaviour, survival, weight gain,
haematology, organ weights and gross pathology (Garvin & Merubia,
One group of 20 male and 20 female and four groups of 10 male and
10 female ARS Sprague-Dawley rats were fed 0, 5 and 10% carbohydrase
(Wallerstein Pectinase Evaporate) and 5 and 10% carbohydrase
(Wallerstein Amylo glycosidase Evaporate) in the diet for 90 days
(roughly equivalent to 3,5 and 7 g preparation/kg bw/day). Appearance
and behaviour were normal, no deaths. Growth rate and food consumption
were similar in all groups. No changes were seen in haematology and
blood chemistry as compared with the respective controls. The relative
weight of thyroid, liver and spleen in males and liver and spleen in
females fed pectinase showed a dose-related decrease. The relative
weight of liver in males and heart in females fed amyloglucosidase
showed a tendency for dose-related decrease. Gross pathology and the
only partly performed histopathology showed chronic pneumonia and
renal tubular obstruction with hyalin casts, which did not seem to be
dose related (Garvin et al., 1972).
Three groups of 10 male and 10 female Charles River rats were fed
0, 5 and 10% of Aspergillus niger mycelial preparation in their diet
for 13 weeks. There were no overt signs of toxicity. Food consumption
and growth were not affected. There was a drop in the efficiency of
food utilization for both dosage groups and both sexes, which was
significant for the high dose males. The haematological, the clinical
and the ophthalmoscopic data, revealed no significant differences
among the groups. There were significant increases in the relative
kidney weight of females in both dosage groups. The gross and
microscopic findings were mostly related to chronic respiratory
disease and kidney lesions including hydropelvis or hydronephrosis,
which did not appear to be treatment related (Swann & Cox, 1973).
Groups of five ducklings received in their diet either 0, 1, 5 or
10% of enzyme for 29 days. Growth, feed consumption, behaviour and
development were comparable in all groups. No gross liver lesions were
seen at autopsy and mean liver weights were similar to controls.
Histopathology of the livers was normal. No toxic element was noted
Mouse, Rat, Cat
Enzyme preparations from Aspergillus niger, strain "Pectolytic"
produced by different cultivation methods were in several different
acute and short-term studies given to a total number of 300 mice,
123 rats and 17 cats. The conclusion of the author is, that surface
and deep culture preparations on media rich in sugars (sugar beet
pulp, wheat bran) gave effects in some experimental animals after
45-750 mg/kg bw/day, of the different preparations mainly given in the
drinking water. The main effects were decreased weight gain, increased
leucocyte count, accelerated sedimentation of erythrocytes and
abscesses different places in the body. A preparation isolated from
the same mould, but cultivated on grain husk had no similar effects on
the animals. The preparation methods are not described, especially is
not revealed whether the preparations were sterile (Magnova, 1968).
Aspergillus niger is a common contaminant of food. The
available information indicates that it is not pathogenic to man.
Duckling studies were done on two preparations and an adequate 90
days' study in rats is now available showing no toxicological effects
at 10% in the diet. This meets the requirements as laid down by the
Acceptable daily intake not specified.*
FDRL (1963) Unpublished report No. 84600f submitted by Miles Chem. Co
Garvin, P. & Merubia, J. (1959) Unpublished report submitted by Baxter
Garvin, P. J. et al. (1966) Unpublished report submitted by Baxter
Garvin, P. J. (1972) Unpublished report No. R.D. 6 - 106 submitted by
R. M. Gesler
Gray, E. H. (1960) Unpublished report submitted by Miles Laboratories
Hunt, R. F. & Garvin, P. J. (1963) Unpublished report submitted by
Baxter Laboratories Inc.
Hunt, R. F. & Garvin, P. J. (1971) Unpublished report submitted by
Travenol Laboratories Ltd
* The statement "ADI not specified" means that, on the basis of the
available data (toxicological, biochemical, and other), the total
daily intake of the substance, arising from its use or uses at the
levels necessary to achieve the desired effect and from its acceptable
background in food, does not, in the opinion of the Committee,
represent a hazard to health. For this reason, and for the reasons
stated in individual evaluations, the establishment of an acceptable
daily intake (ADI) in mg per kg of body weight is not deemed
Kay, J. H. & Calandra, J. C. (1962) Unpublished report submitted by
Miles Chemical Co
Magonova, N. B. (1968) Voprosy pitania, 27, 67-72
Phillips, B. M., Hartnagel, R. E. & Thompson, D. (1967) Unpublished
report submitted by Miles Chemical Co
Sachsse, K. (1971) Unpublished report No. Siss 826 submitted by Ciba
Sachsse, K. & Bathe, R. (1971) Unpublished report No. Siss 826
submitted by Ciba-Geigy
Swann, H. E. & Cox, G. E. (1973) Unpublished report laboratory No.
1223 submitted by Searle Biochemicals
Willard, R. L. & Garvin, P. J. (1968) Unpublished report submitted by
Travenol Laboratories Ltd