ETHYL LACTATE
Explanation
The biological data on ethyl lactate were reviewed at the
eleventh meeting of the Joint FAO/WHO Expert Committee on Food
Additives, specifications were prepared, and a conditional acceptable
daily intake for man (ADI) of 0-100 mg/kg bw (as total D(-) - lactic
acid from all food additive sources) was established (FAO/WHO, 1967;
FAO/WHO, 1968). Since this previous review, new data have become
available and are included in this monograph.
BIOLOGICAL DATA
BIOCHEMICAL ASPECTS
Substantial evidence has accumulated that simple esters readily
undergo enzymatic hydrolysis into their component acids and alcohols
(FEMA, 1974; Longland et al., 1977; Grundschober, 1977). It can be
presumed that ethyl lactate is readily hydrolysed in the body to ethyl
alcohol and lactic acid, both of which are common food constituents
(Fassett, 1963). The metabolic fate of ethyl alcohol is well-known
(FEMA, 1974) and lactic acid is, of course, a normal and essential
intermediate in human metabolism (Oser, 1965). The metabolism of
lactic acid has been studied extensively, both in humans and in other
mammals (Informatics, Inc., 1975; FEMA, 1977).
TOXICOLOGICAL STUDIES
Acute toxicity
None available.
Short-term studies
Rat
Ethyl lactate was reportedly a good energy source and enhanced
growth in a group of eight male weanling rats fed a diet containing 5%
of this ester (approximately equivalent to 5 g/kg bw) over a period of
12 days. One of eight animals died during the course of the experiment
(there was no indication of the cause of death). No adverse effects
were observed in the surviving animals (Yoshida et al., 1971).
Long-term studies
None available.
Comments
Data to show enzymatic hydrolysis of ethyl lactate to ethyl
alcohol and lactic acid were not available. However, this postulated
hydrolysis is well supported by data on closely related esters,
including ethyl acetate and ethyl butyrate. The evaluation of ethyl
lactate is based on the short-term study and the assumed metabolic
fate of closely related substances. After positive evidence of
hydrolysis is available, the ADI for ethyl lactate may be subsumed
under the group ADI for lactic acid.
EVALUATION
Estimate of temporary acceptable daily intake for man
Group ADI for lactic acid: 0 - 12.5 mg/kg/bw
FURTHER WORK OR INFORMATION
Required by 1980
An in vivo hydrolysis study.
REFERENCES
FAO/WHO (1967) Toxicological evaluation of some flavouring substances
and non-nutritive sweetening agents. FAO Nutrition Meetings
Report Series No. 44a; WHO/Food Add./68.33
FAO/WHO (1968) Specifications for the identity and purity of food
additives and their toxicological evaluation: some flavouring
substances and non-nutritive sweetening agents. Eleventh Report
of the Joint FAO/WHO Expert Committee on Food Additives. FAO
Nutrition Meetings Report Series No. 44; Wld Hlth Org. techn.
Rep. Ser. No. 383
Fassett, D. W. (1963) In: Patty, F. A., ed., Industrial hygiene and
toxicology, second edition, Interscience, New York and London
FEMA (1974) Scientific literature review of aliphatic primary
alcohols, aldehydes, esters, and acids in flavor usage, published
by the National Information Services under Contract with the
Food and Drug Administration
FEMA (1977) Scientific literature review of propylene glycol, glycerol
and related substances in flavor usage, published by the
National Information Services under Contract with the Food and
Drug Administration
Grundschober, F. (1977) Toxicological assessment of flavouring esters,
Toxicology, 8, 387-390
Informatics, Inc. (1975) Scientific literature reviews on generally
recognized as safe (GRAS) food ingredients. Lactic acid, US Food
and Drug Administration, Washington, D.C.
Longland, R. C., Shilling, W. H. & Gangolli, S. D. (1977) The
hydrolysis of flavouring esters by artificial gastrointestinal
juices and rat tissue preparations, Toxicology 8, 197-204
Oser, B. L. (1965) Physiological chemistry, McGraw-Hill Book Company
Yoshida, M., Ikumo, H. & Suzuki, O. (1971) Evaluation of available
energy of aliphatic chemicals by rats: an application of bioassay
of energy to mono-gastric animal, Agr. Biol. Chem., 35 (8),
1208-1215