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