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
HYDROGEN PEROXIDE
Chemical name Hydrogen peroxide
Empirical formula H2O2
Molecular weight 34.02
Definition Hydrogen peroxide suitable for food use
contains the amount of H2O2 as specified
by the vendor (usually between 30 and 50 per
cent.).
Description Hydrogen peroxide is a colourless liquid,
containing stabilizer appearing in the
residue on evaporation
Caution Powerful oxidizing agent. Avoid contact with
eyes and skin.
Uses As an antimicrobial or bleaching agent.
Biological Data
Biochemical aspects
When hydrogen peroxide is used as an agent to reduce the number
of bacteria in dairy products or other foodstuffs, the excess is
destroyed. Toxicological considerations, therefore, apply only to the
possible interference with the nutritional value of treated foodstuffs
or the formation of toxic substances, but not to residual hydrogen
peroxide. It is well known that small amounts of hydrogen peroxide
given orally produce no toxicological effects, because of the rapid
decomposition by the catalase of the intestinal cells. However, a 0.45
per cent. solution given to rats instead of drinking water depressed
the fluid intake and food consumption and reduced the body-weight
(Hankin, 1958). Some hydrogen peroxide was absorbed sublingually,
causing visible gas bubbles in the veins (Ludewig, 1959).
Dilute solutions of hydrogen peroxide (0.25 per cent.) caused no
changes in casein detectable by electron microscopy.The rennet
coagulation time of milk or of a pure casein solution treated with
hydrogen peroxide was prolonged. Crystallized serum albumin treated
with hydrogen peroxide also showed no detectable changes. On the other
hand, hydrogen peroxide caused a dissociation of the ß-lactoglobulin
molecule and, therefore, some alterations in the electrophoretic
patterns of whey. The addition of 0.25 per cent. of hydrogen peroxide
for 2 days at 30° or 20 minutes at 55° did not noticeably reduce the
sulfhydryl groups of milk proteins (Lück & Joubert, 1955a; 1955b;
1955c). No effect on the electrophoretic patterns of the milk proteins
attributable to the treatment of milk with 0.1, 0.2 and 0.5 per cent.
hydrogen peroxide at 120° F has been observed (Tepley et al., 1958).
Treatment of milk with 0.3 per cent. hydrogen peroxide for 24
hours at 30° or 30 minutes at 51° had no detectable influences on the
milk fat or the fat soluble vitamins A and D3 and ß-carotene (Lück &
Schillinger, 1958a); the water soluble vitamins thiamine, riboflavin
and pyridoxine were also not affected, but ascorbic acid was nearly
completely destroyed (Lück & Schillinger, 1958b). Treatment of milk
with 0.1, 0.2 and 0.5 per cent. hydrogen peroxide had no influence on
the content of the milk or wheys, on the vitamins thiamine,
riboflavin, niacin, pyridoxine, pantothenic acid, folic acid, vitamin
B12, vitamin A and ß-carotene. Treatment of milk with 0.5 per cent.
hydrogen peroxide lowered the values for cystine and methionine in the
cheese made from this milk by 10-25 per cent., but values for
tryptophan and lysine were not affected (Tepley et al., 1958).
Acute toxicity
No data on the acute toxicity of foodstuffs or food components
treated with hydrogen peroxide are available.
Short-term studies
Rat. Groups of 10 male weanling rats were fed for 6 weeks 9 per
cent. milk protein or cheese protein of pasteurized milk treated with
0, 0.1, 0.2 and 0.5 per cent. hydrogen peroxide. The biological value
of the proteins was not altered, with the exception of a slightly
depressed value for milk treated with 0.5 per cent. hydrogen peroxide
at 160°F. All animals remained in good health and autopsy showed no
abnormalities (Tepley et al., 1958).
Comments
The destruction of ascorbic acid in milk is not considered
nutritionally important as it is a minor source of this vitamin;
pasteurization has an equally destructive effect. Biochemical studies
and short-term animal studies with hydrogen peroxide treated milk and
cheese support the view that milk treated with hydrogen peroxide may
be safe. However, long-term studies are lacking.
Evaluation
Because of the instability of the compound in contact with food,
it is not possible to allocate to it a meaningful acceptable daily
intake for man. However, in circumstances where more acceptable
methods of milk preservation are not available, hydrogen peroxide may
be used for this purpose.
Further work required
Long-term toxicity studies on milk treated with various levels of
hydrogen peroxide.
REFERENCES
Hankin, L. (1958) Nature, 162, 1453
Lück, H. & Joubert, F. J. (1955a) Milchwiss, 10, 160
Lück, H. & Joubert, F. J. (1955b) Milchwiss., 10, 370
Lück, H. & Joubert, F. J. (1955c) Biochem. Z., 327, 221
Lück, H. & Schillinger, A. (1958a) Z. Lebensmittelunters, 108, 341
Lück, H. & Schillinger, A. (1958b) Z. Lebensmittelunters., 107, 512
Ludewig, R. (1959) Z. ges. exp. Med., 131, 452
Tepley, L. J., Derse, P. H. & Price, W. V. (1958) J. Dairy
Sci.,41, 593