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.
CAROB BEAN GUM
Explanation
This substance has been evaluated for acceptable daily intake by
the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
Ref. No. 19) in 1969.
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.
BIOLOGICAL DATA
BIOCHEMICAL ASPECTS
Groups each of eight male Holtzman rats were maintained on a
purified synthetic diet, or the diet plus 1% cholesterol, or the diet
plus 1% cholesterol plus 10% carob bean gum, for 28 days. The
increased liver cholesterol and liver total lipid induced by
cholesterol feeding was largely counteracted by concurrent feeding of
carob bean gum (Ershoff & Wells, 1962).
TOXICOLOGICAL STUDIES
Special studies
Eight infants between the ages of two-and-a-half to five months
were fed meals of sugared milk or sugared milk plus 1% powder
extracted from carob bean. Addition of the carob bean extract
supplement did not alter the duration of the gastrointestinal transit
time of the meal. Physiological aerophobia was markedly suppressed by
the carob bean extract supplement (Rivier, 1952).
Short-term studies
Rat
A study is under way in which 10 male and 10 female rats per
group are being fed 1, 2 and 5% carob bean gum (Til & Spanjers, 1973).
Chickens
Groups of 20-day-old chicks were fed diets containing 0.25, 0.5,
1 and 2% carob bean gum for three weeks. Growth depression was dose-
related and marked at 2% level of intake (Kratzer et al., 1967; Vohra
& Kratzer, 1964).
Long-term studies
None available.
OBSERVATIONS IN MAN
A clinical study of a commercial preparation of carob gum as a
laxative in doses of "two heaping teaspoonfuls" in 56 patients, some
of whom took the preparation regularly for two years, resulted in no
untoward effects related to the gastrointestinal tract, and no
allergic reactions (Holbrook, 1951).
Comments:
Carob bean gum (locust bean gum) is used in pharmaceutical
preparations. There is little evidence on its metabolism and a short-
term study in rats is in progress. More information on the metabolism
in other species including man and another short-term study in a non-
rodent species are required.
EVALUATION
Not possible on the data provided.
REFERENCES
Ershoff, B. H. & Wells, A. F. (1962) Proc. Soc. Exptl. Biol. Med.,
110(3), 580-582
Holbrook, A. A. (1951) Amer. J. dig. Dis., 18, 24
Kratzer, F. H., Rajaguru. R. W. A. S. B. & Vohra, P. (1967) Poultry
Sci., 46(6), 1489-1493
Rivier, C. (1952) Schweiz. Med. Wschr., 82(10), 256-258
Til, H. P. & Spanjers, M. T. H. (1973) Unpublished report No. 4093
from TNO
Vohra, P. & Kratzer, F. H. (1964) Poultry Sci., 43(5), 1164-1170