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 AMMONIUM PERSULFATE Chemical name Ammonium persulfate Empirical formula (NH4)2S2O8 Molecular weight 228.20 Definition Ammonium persulfate contains not less than 95 per cent. (NH4)2S2O8 Description Ammonium persulfate occurs as colourless crystals, white crystalline powder. Caution Powerful oxidising substance. Use As a strengthening agent for flour. Biological Data (See Potassium Persulfate) POTASSIUM PERSULFATE Chemical name Potassium persulfate Empirical formula K2S2O8 Molecular weight 270.32 Definition Potassium persulfate contains less than 95 per cent. of K2S2O8. Description Potassium persulfate occurs as colourless or white, odourless crystals. Caution Powerful oxidizing substance. Use As a strengthening agent for flour. Biological Data Biochemical aspects Persulfate is converted to bisulfate and sulfate in bread. Sulfates are slowly absorbed; large amounts may cause purgation. Sulfates are formed in the body physiologically and excreted in the urine as conjugates. The nutritional value of gluten has been studied by examination of the amino acid pattern before and after treatment with ammonium persulfate at levels of 100 and 2000 ppm. At the lower level of treatment no significant change in amino acids, other than in methionine, was found. The higher level of treatment resulted in 46 per cent. loss of tryptophan, 20 per cent. loss of methionine and slight losses of cystine, arginine and lysine. It also reduced the digestibility of the protein by 21 per cent.; no significant effect on digestibility was seen at the lower level of treatment (Schörmüller et al., 1953). In studies on bread baked from flour treated at 100 ppm, reduction of methionine was not observed, even after one month's storage (Jansen et al., 1955). Special studies It has been claimed that flour treated with ammonium persulfate is liable to cause dermatitis in bakers (Teleky & Zitzke, 1932). Skin tests ware reported to show sensitivity to ammonium persulfate (Badham, 1935). These results have not been subsequently confirmed (Amos, 1951; Maltha, 1954). Acute toxicity No data are available. Short-term tests Rat. Groups of rats fed diets containing a high proportion of flour or bread made from flour treated with ammonium persulfate at levels of 0.02 and 0.1 per cent. showed no ill effects over a six-month period. Weight gain, reproductive performance and microscopical appearance of main organs were studied. The study was carried through two generations (Arnold & Goble, 1949; Arnold & Goble, 1950). Dog. Twelve dogs were fed on diets containing a high flour content for a period of 5.5-16 months. The flour was treated with 0, 0.12 or 0.8 per cent. ammonium persulfate. No differences between the control and test animals were observed with regard to weight gain, appearance, renal function, haematology, urinary constituents, and gross or microscopic appearance of major organs (Arnold & Goble, 1950). In another experiment dogs were fed flour treated at 0.027, 0.121 and 0.808 per cent. for various periods up to 90 days without obvious ill effects (Arnold, 1949; Bentley et al., 1948). Long-term studies None appear to be available, using either ammonium persulfate or ammonium sulfate on treated flour or bread baked from it. Comments While one would not ascribe any serious significance to a small residue of sulfate, there is a serious lack of long-term studies on persulfate-treated flour or bread baked from it. There is some suggestion that flour treated with ammonium persulfate is liable to cause skin sensitization. Such studies as have been done on possible toxic substances produced by treatment were strongly orientated towards the production of "running fits", which we now know could not be a hazard in this case. Further work is needed on the nutritional aspects, particularly the vitamin content of treated flour and bread. Evaluation In the absence of more adequate toxicological data, it is not possible to estimate an acceptable treatment level of flour. Nevertheless it is not considered necessary to discontinue the use of persulfates at present. Further studies required Adequate long-term studies are needed on flour treated at several dose levels with ammonium persulfate and bread baked from it. REFERENCES Amos, A. J. (1951) Chem. and Ind., 45, 946 Arnold, A. (1949) Cereal Chem., 26, 46 Arnold, A. & Goble, F. C. (1949) Fed. Proc., 8, 377 Arnold, A. & Goble, F. C. (1950) Cereal Chem., 27, 375 Badham, C. (1930-35) Annual Report of the Public Health Department, New South Wales, 71 Bentley, H. R., Booth, R. G., Green, E. E., Heathcote, J. G., Hutchinson, J. B. & Moran, T. (1948) Nature (Lond), 161, 126 Jansen, A. P., Van der Linden, A. C. & Wöstmann, B. S. T. (1955) Z.Lebenm. Unters. Forschg., 100, 345 Maltha, P. (1954) Die Mühle, 91, 2 Schörmüller, J., Störig, I. & Leichter, L. (1953) Z. Lebenm. Unters. Forschg., 96, 1 Teleky, L. & Zitzke, E. (1932) Archiv. Gewerbepath. und Gewerbehygiene, 3, 68
See Also: Toxicological Abbreviations