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
TRIACETIN
BIOLOGICAL DATA
BIOCHEMICAL ASPECTS
Numerous studies have shown that triacetin is rapidly hydrolysed
in vitro by all tissues of the organism including the gastro-
intestinal tract (Bach & Metais, 1970). This property has been
utilized for the estimation of tissue esterase concentrations by
employing triacetin as enzyme substrate (Gomori, 1945; Archibald,
1946) and has been confirmed in studies comparing lipase and esterase
activities, the latter acting far more rapidly and especially the
shorter the fatty acid chain length (Desnuelle, 1961; Desnuelle &
Savary, 1963; Entressaugles et al., 1961; Greenberger et al., 1966;
Isselbacher, 1966; Sampugna et al., 1967). Tissue esterases are active
in combination with acetokinase of Lipman (acetyl CoA synthetase) at
the cellular level especially in hepatic and cardiac tissue. Triacetin
is more rapidly absorbed from the gastro-intestinal tract in three
hours than the other fats tested (Deuel & Hallman, 1940). Triacetin
has been shown to be a source of liver glycogen (Deuel et al., 1937)
and when fed in amounts equal in caloric value to 15% glucose it was
utilized as efficiently as was glucose (McManus et al., 1943). The
rate of hydrolysis by pancreatic lipase in vitro is increased by
surface active agents (Nishida, 1957).
TOXICOLOGICAL STUDIES
Acute toxicity
Species Route LD50 Reference
mg/kg body weight
Mouse S.c. 2 670 Spector, 1956
I.p. 1 400-1 700 Gast, 1963
Rat S.c. 3 250 Spector, 1956
Comments:
Although no formal short and long-term studies are available, it
is reasonable to conclude that triacetin is metabolized like other
fats in food and to take this into account for evaluation as well as
its ready hydrolysis by non-specific tissue esterases.
EVALUATION
Estimate of acceptable daily intake for man
Acceptable daily intake not specified.*
REFERENCES
Archibald, R. M. (1946) The determination of lipase activity,
J. biol. Chem., 165, 443
Bach, A. & Metais, P. (1970) Graisses à chaînes nes courtes et
moyennes: aspects physiologiques, biochimiques, nutritionnels et
thérapeutiques, Ann. Nutr. Alim., 24, 75-144
Desnuelle, P. (1961) Pancreatic lipase, Advanc. enzymol., 23, 129
Desnuelle, P. & Savary, P. (1963) Specificities of lipases, J. Lip.
Res., 4, 369-384
Deuel, H. J., jr, Butts, J. S., Blunden, H., Cutler, C. H. & Knott, L.
(1937) Studies on ketosis. IX. Glycogen formation from various
purified and natural fats, J. biol. Chem., 117, 119
Deuel, J. H., jr & Hallman, L. (1940) The rate of absorption of
synthetic triglycerides in the rat, J. Nutr., 20, 227-232
Entressaugles, B., Pasero, L., Savary, P., Sarda, L. & Desnuelle, P.
(1961) The influence of the nature of the acid substituents in
glycerides upon the rate of hydrolysis by pancreatic lipase,
Bull. Soc. Chim. biol., 43, 581-591
Gast, J. H. (1963) Some toxicity studies with triacetin, Fed. Proc.,
22, 368
Gomori, G. (1945) The microtechnical demonstration of sites of lipase
activity, Proc. Soc. Exp. Biol. Med., 58, 362
* 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/kg bw is not deemed necessary.
Greenberger, N.J., Rodgers, J. B. & Isselbacher, K. J. (1966)
Absorption of medium and long chain triglycerides: factors
influencing their hydrolysis and transport, J. Clin. Invest.,
45, 217-227
McManus, T. B., Bender, C. B. & Garrett, O. F. (1943) A comparison of
acetic acid fed in form of triacetin with glucose as a nutrient
in feeds, J. Dairy Sci., 26, 13-23
Nishida, M. (1957) Hydrolysis of solubilized esters in pancreatic
lipase. IV. Yakugaku Zasshi, 77, 1141-1145
Sampugna, J., Quinn, J. G., Pitas, R. E., Carpenter, D. L. & Jensen,
R. G. (1967) Digestion of butyrate glycerides by pancreatic
lipase, Lipids, 2, 397-402
Spector, W. (1956) Handbook of Toxicology. Acute toxicities, Vol. 1,
302