ACID-TREATED STARCHES

    Explanation

         This modified starch was previously evaluated for an ADI for man
    by the Joint FAO/WHO Expert Committee on Food Additives in 1969, 1971
    and 1973 (see Annex I, Refs. 19, 26 and 29). Toxicological monographs
    were published in 1969, 1972 and 1974 (see Annex I, Refs. 20, 27 and
    30).

         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.

    Introduction

         These modified starches represent an intermediate stage in the
    normal enzymatic digestion of food starch in the human body. This
    process also occurs in the human stomach and results in hydrolysis of
    some of the linkages between adjacent anhydroglucose units with a
    reduction of the mean molecular weight of these starch molecules.
    Starch is a polymer of glucose and contains 2 major polysaccharide
    components, amylase and amylopectin. In the commercial process
    hydrochloric, sulfuric or phosphoric acid is used and the excess is
    neutralized with sodium hydroxide or sodium carbonate.

         Subsequent treatment of the modified starch ensures that only
    traces of either sodium chloride, sodium sulfate or sodium hydrogen
    phosphate remain behind.

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         Diets containing 63.7% of an acid-modified wheat starch was 97.8%
    digested in 28-day feeding experiments with weanling rats. Weight
    gains were similar to those for unmodified wheat starch (Booher et
    al., 1951).

    TOXICOLOGICAL STUDIES

    Acute toxicity

         Intragastric administration of doses larger than 100 ml/kg of a
    60% paste of a soluble acid-hydrolysed potato starch resulted in
    gastric rupture (Boyd & Liu, 1968).

    Short-term studies

    Pig

         Groups of Pitman-Moore miniature pigs were weaned at 3 days of
    age and maintained for 25 days on diets where 25% of the calories were
    contributed by an acid-modified waxy cornstarch. Cholesterol and
    triglyceride levels were lower, and relative liver weight was lower in
    these animals than in sow-reared pigs; serum urea levels were higher
    even though protein levels were said to be similar (Anderson et al.,
    1973, 1974; Filer et al., 1973).

    Comments

         These starches should be regarded as normal constituents of food.

    EVALUATION

    Estimate of acceptable daily intake for man

    Not specified.*

              

    *    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.

    REFERENCES

    Anderson, T. A. et al. (1973) Effect of waxy corn starch modification
         on growth, serum biochemical values and body composition of
         Pitman-Moore miniature pigs, Fd. Cosmet. Toxicol., 11,
         747-754

    Anderson, T. A. (1974) Digestibility of acetylated distarch glycerol -
         effect on growth, serum biochemical values, and body composition
         of Pitman-Moore miniature pigs, Fd. Cosmet. Toxicol., 12,
         201-207

    Booher, L. E., Behan, I. & McMeans, E. (1951) Biological utilizations
         of unmodified and modified food starches, J. Nutr., 45, 75-99

    Boyd, E. M. & Liu, S. J. (1968) Toxicity of starch administered by
         mouth, Can. Med. Assoc. J., 98, 192-199

    Filer, L. J., Jr et al. (1973) Growth, serum chemical values and
         carcass composition of Pitman-Moore miniature pigs during the
         first eight weeks of life, J. Nutr., 103, 425-437
    

    See Also:
       Toxicological Abbreviations
       Acid-treated starches  (FAO Nutrition Meetings Report Series 46a)
       Acid-treated starches (WHO Food Additives Series 5)