Trends and Perspectives in Food Contaminants
Historically, food legislation in the UK has been concerned with the adulteration of food. Prior to the introduction of substantive food laws in the second half of the nineteenth century, the control of food quality had been in the hands of officials appointed by Trade Guilds. The development of analytical chemistry in the late nineteenth century provided a means of control based on identification of ingredients and common adulterants or contaminants.
Early legislation concentrated on the sale of foods containing injurious contaminants and the use of adulterants. The principal offences created by the Act of 1875 were: firstly, mixing of injurious ingredients with any article of food sold or intended for sale and the selling of the article so prepared; and secondly, selling to the prejudice of the purchaser a food which was not of the nature, substance and quality demanded. These two basic aspects have stood the test of time, and are found in current legislation. The first requires a proof of injuriousness, the second is based on evidence of composition; both are matters of opinion, though in some areas Ministers have, in accordance with powers given to them by the Act, made regulations which in effect leave room only for analytical opinion.
The adulterants of the nineteenth century have now largely if not completely disappeared; but it may be argued that their place has been taken by others which have become available through technological progress such as added water, excessive fat or the improved recovery of meat from carcases. Since these are the same as, or only relatively simple variations of, constituents already present, the analytical problems have increased. This is in marked contrast to the analytical position regarding trace contaminants, where separation and detection techniques have greatly improved in recent decades.
In the past 30 years the development of regulations controlling various contaminants followed the tendency for compositional regulations which originated 50–60 years ago and is still in progress. This has extended to technological additives, where these are permitted; but with a few specific exceptions, notably arsenic and lead, control of contaminants has been left to the general provisions of the Act controlling the fitness of food for consumption. This provides flexibility of control and encourages the concept of good manufacturing practice.
The development of increasingly sensitive analytical methods has focused attention on the presence of many harmful or potentially harmful substances which are present in minute amounts in many foods. These may be held to render the food harmful to health or unfit for consumption, but the assessment will again be a matter for opinion and judgement. Contaminants may be of technological origin, such as trace metals derived (for example) from processing equipment or residues of agricultural or veterinary chemicals; or they may derive from minerals occurring naturally in the soil or water of the locality in which the produce was grown or reared. Contaminants which render a food unfit may be of chemical or of microbiological origin; the fact that microbiological contamination involves chemical metabolites is becoming increasingly apparent.
Examples of development in techniques and improvements in limits of detection and the problem arising from pursuit of ‘zero tolerance’ will also be discussed.
KeywordsHigh Performance Liquid Chromatography Pesticide Residue Vinyl Chloride Packaging Material General Provision
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- 1.Chirnside, R. C. and Hamence, J. H. (1974). The Practising Chemists. Society for Analytical Chemistry, London.Google Scholar
- 2.Leach, A. E. and Winton, A. L. (1920). Food Inspection and Analysis. 4th edition, John Wiley and Sons, New York.Google Scholar
- 4.Lawrence, J. F. (1976). J. Ass. Off. Anal. Chem., 59, 1066.Google Scholar
- 6.Draft Commission Directive 4850/VI/77-Rev 3. 10.11.78.Google Scholar
- 8.Cheng, E. W. and Burroughs, W. (1955). J. Ass. Off. Anal. Chem., 38, 146.Google Scholar
- 9.Munsey, V. E. (1959). J. Ass. Off. Anal. Chem., 42, 250.Google Scholar
- 10.Smiley, I. E. and Schall, E. D. (1969). J. Ass. Off. Anal. Chem., 52, 107.Google Scholar
- 11.Jeffus, M. T. and Kenner, C. T. (1973). J. Ass. Off. Anal. Chem., 56, 1483.Google Scholar
- 12.Jones, O. and Deathrage, F. E. (1953). Food Res., 18, 30.Google Scholar
- 13.Donoka, A. L., Johnson, W. S., Sieck, R. F. and Sullivan, W. L. (1973). J. Ass. Off. Anal. Chem., 56, 785.Google Scholar
- 14.Ponder, C. (1974). J. Ass. Off. Anal. Chem., 57, 919.Google Scholar
- 15.Day, E. W., Vanatta, L. E. and Sieck, R. F. (1975). J. Ass. Off. Anal. Chem., 58, 520.Google Scholar
- 18.Henricks, D. M. and Torrence, A. K. (1978). J. Ass. Off. Anal. Chem., 61, 1280.Google Scholar
- 19.Mondain-M-G, M., Castanier, M. and Scholler, R. (1970). C.R. Acad. Sci., Ser. D., 2381.Google Scholar
- 22.Anon. (1977). Cereal Food World, 22, 10.Google Scholar
- 23.Association of Official Agricultural Chemists (1975). Official Methods of Analysis. AOAC, Washington DC, Chap. 26.Google Scholar
- 25.Pons, W. A. (1976). J. Ass. Off. Anal. Chem., 59, 101.Google Scholar
- 26.Lawellin, D. W., Grant, D. W. and Joyce, B. K. (1977). Appl. Env. Microbiol., 34, 94.Google Scholar
- 28.Schuller, P. L., Horwitz, W. and Stoloff, L. J. (1976). J. Ass. Off. Anal. Chem., 59, 1315.Google Scholar
- 31.Graf, W. (1965). Med. Klim., 60, 561.Google Scholar
- 32.Guerreor, H., Biehl, E. R. and Kenner, C. T. (1976). J. Ass. Off. Anal. Chem., 59, 989.Google Scholar
- 33.Lo, M. T. and Sandi, E. (1978). Residue Reviews, 69, 35.Google Scholar
- 35.Howard, J. W., Fasio, T., White, R. H. and Klimech, B. A. (1968). J. Ass. Off. Anal. Chem., 51, 122.Google Scholar
- 36.Hunt, D. C., Wild, P. J. and Crosby, N. T. (1977). Rapp R.V Reun. Cons. int. Explor. Mer., 171, 41.Google Scholar
- 37.Novotny, M., Lee, M. L. and Bartle, K. D. (1974). J. Chromatogr. Sci., 12, 606.Google Scholar
- 41.Crosby, N. T. (1976). Residue Reviews, 64, 78.Google Scholar
- 42.International Agency for Research on Cancer, Lyon (1978). Environmental aspects of N-nitroso compounds.Google Scholar
- 44.Cunningham, H. M. and Pontefract, R. D. (1973). J. Ass. Off. Anal. Chem., 56, 976.Google Scholar
- 46.Miscellaneous Additive in Food Regulations (1974). No 1121, HMSO, London.Google Scholar
- 47.Food Additives and Contaminants Committee (1970). Report: The Leaching of Substances from Packaging Materials into Food, HMSO, London.Google Scholar
- 48.Directive 76/893/EEC, Official Journal of the European Communities, (1976). No. L340, p. 19, Dec. 19th.Google Scholar
- 49.Materials and Articles in Contact with Food Regulations 1978, S.I. 1978 No 1927. HMSO.Google Scholar
- 50.Directive 78/142/EEC, Official Journal of the European Communities, (1978). No L44, p. 15, Feb. 15th.Google Scholar
- 51.Survey of Vinyl Chloride Content of Polyvinyl Chloride for Food Contact and of Foods. Food Surveillance Paper No 2, (1978), HMSO.Google Scholar