FAO Nutrition Meetings
Report Series No. 40A,B,C
WHO/Food Add./67.29
TOXICOLOGICAL EVALUATION OF SOME
ANTIMICROBIALS, ANTIOXIDANTS, EMULSIFIERS,
STABILIZERS, FLOUR-TREATMENT AGENTS, ACIDS AND BASES
The content of this document is the result of the deliberations of the
Joint FAO/WHO Expert Committee on Food Additives which met at Rome,
13-20 December, 19651 Geneva, 11-18 October, 19662
1 Ninth Report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series, 1966 No. 40;
Wld Hlth Org. techn. Rep. Ser., 1966, 339
2 Tenth Report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series, 1967, in press;
Food and Agriculture Organization of the United Nations
World Health Organization
1967
LACTIC ACID AND FATTY ACID ESTERS OF GLYCEROL
Synonyms Lactated mono- and diglycerides; Lactic
acid esters of mono- and diglycerides
Chemical description The product consists of mixed glycerol
esters of lactic acid and fatty acids.
Structural formula A major component is:
CH2-OR
'
CH-OR'
'
CH2-OR"
Where at least one of R, R' or R"
represent the lactic acid moiety, the
remainder may represent the fatty acid
moiety or hydrogen.
Description Lactated mono- and diglycerides are waxy
solids of variable consistency.
Uses As emulsifier.
Biological Data
Biochemical aspects
Lactoglycerides consist of various esters; in commercial products
the glycerol lactopalmitate and stearate are the predominant
components. Almost all toxicological work has been carried out on
glycerol lactopalmitate (GLP).
Study of glycerol lactopalmitate (GLP) hydrolysis in the presence
of hog pancreatic lipase revealed rapid disruption of the ester
linkage, yielding glycerol, lactic acid and palmitic acid as sole
reaction products (Treon et al., 1962).
In another study, no deleterious effect was shown by additional
GLP or the theoretical intermediate compound glycerol monolactate on
the in vitro hydrolysis of olive oil by lipase. Hydrolysis, in fact,
proceeded more, rapidly as shown by enhanced liberation of carboxylic
acid. On the other hand, glycerol monolactate hydrolysed spontaneously
and rapidly without enzyme intervention (McKennis et al., 1958).
14C-labelled GLP (at the lactate-2-C, site) was fed to dogs by
intubation and the appearance of labelled lactic acid in thoracic duct
lymph and blood was studied. Normal levels were found and the
presence of lactate-2-C14in these fluids showed digestion and
absorption of GLP to have occurred. The lactate-2-C14 disappeared
rapidly from lymph and blood. 14C-labelled GLP (at the glycerol-1,3-C
sites) was metabolized by rats to the same extent as glycerol-1,3-C14
as shown by the amount of 14C0 2 found in expired air. GLP was
metabolized by the dog similarly to the rat, some 50 per cent. of the
administered dose appearing as expired 14CO2 over 48 hours (McKennis
et al., 1958).
Acute toxicity
Two groups of 6 male rats each ware given GLP suspended in water
by intubation in doses of 8.65 g and 5.75 g/kg body-weight
respectively. All animals survived without systemic effects other than
those attributable to mechanical distension. Gross appearance of major
organs was found to be normal after 14 days (Gongwer, 1959).
Short-term studies
Rat. A number of experiments using small numbers of animals
were done and revealed no toxic effects (Kaunitz, 1958).
Long-term studies
Rat. A number of experiments using small numbers of animals
were done and revealed no toxic effects (Fye & Katz, 1953).
Comments
The metabolic studies indicate that the lactic acid and fatty
acid esters of glycerol are completely hydrolysed in the
gastrointestinal tract to lactic acid, glycerol and fatty acids. The
evidence with labelled lactic acid shows that the metabolism of bound
lactic acid in the rat is not significantly different from that of
free lactic acid.
Evaluation is based on the biochemical and metabolic studies. The
use of this additive is limited by the content of D(-)-lactic acid,
for which an acceptable daily intake has been established (FAO/WHO,
1966).
Evaluation
Estimate of acceptable daily intake for man
See mixed tartaric and acetic and fatty acid esters of glycerol, p.
96.
REFERENCES
FAO/WHO (1966) FAO Nutrition Meetings Report Series No. 40;
Wld Hlth Org. techn. Rep. Ser.,339, p. 20
Fye, D. J. & Katz, H. C. (1953) Unpublished report to WHO
Gongwer, L. E. (1959) Unpublished report to WHO
Kaunitz, H. (1958) Unpublished report to WHO
McKennis, H, Turnbull, L. B, Haag, H. R. & Larson, P. S. (1958)
Proc. Soc. exp. Biol., 97, 498
Treon, J. F., Brin, M., Domingues, F. J., Smullin, C. F, Lowry, J. R.
& Helmick, M. (1962) J. Agric. Food Chem., 10, 111