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
    

    See Also:
       Toxicological Abbreviations
       Ethyl lactate (FAO Nutrition Meetings Report Series 44a)
       Ethyl lactate (WHO Food Additives Series 15)
       ETHYL LACTATE (JECFA Evaluation)