Food residues

The addition of therapeutic or cosmetic agents to dentifrices has paralleled advances in knowledge about factors affecting the human dentition. Agents added to dentifrices can act directly on the host tooth stmcture or on specific oral accumulations, for example, the principal action of fluoride is on the tooth enamel. The primary action of an abrasive, however, is on an accumulated stained pellicle. Oral accumulations of interest to preventive dentistry are dental pellicles, dental plaque, dental calculus (tartar), microbial populations responsible for oral malodor, and oral debris (food residues, leukocytes, etc). Plaque is most important because of its potential to do harm. 

Bacterial catabolism of oral food residue is probably responsible for a higher [NHj] in the oral cavity than in the rest of the respiratory tract.Ammonia, the by-product of oral bacterial protein catabolism and subsequent ureolysis, desorbs from the fluid lining the oral cavity to the airstream.. Saliva, gingival crevicular fluids, and dental plaque supply urea to oral bacteria and may themselves be sites of bacterial NH3 production, based on the presence of urease in each of these materials.Consequently, oral cavity fNTi3)4 is controlled by factors that influence bacterial protein catabolism and ureolysis. Such factors may include the pH of the surface lining fluid, bacterial nutrient sources (food residue on teeth or on buccal surfaces), saliva production, saliva pH, and the effects of oral surface temperature on bacterial metabolism and wall blood flow. The role of teeth, as structures that facilitate bacterial colonization and food entrapment, in augmenting [NH3J4 is unknown. 

Deal, M. (1990), Exploratory analysis of food residues from prehistoric pottery and other artifacts from eastern Canada, SAS Bull. 13(1), 6-12. 

R. P. Evershed, C. Heron, S. Charters and L. J. Goad, The survival of food residues new methods of analysis, interpretation and application. In A. M. Pollard (ed.), New Developments in Archaeological Science. Proceedings of the British Academy, 77, Oxford University Press, Oxford, 1992, 293 p. 

Morton, J. D. and Schwarcz, H. P. (1988) Stable isotope analysis of food residues from Ontario ceramics In 26th International Archaeometry Symposium, Toronto (Ed. Farquarhar, R.), University of Toronto, Toronto, pp. 89 93. 

Patrick, M., Koning, A. J. and Smith, A. B. (1985) Gas liquid chromatographic analysis of fatty acids in food residues from ceramics found in the Southwestern Cape. Archaeomtery 27, 231 236. 

Needham, S. and Evans, J. (1987). Honey and dripping Neolithic food residues from Runnymede Bridge. Oxford Journal of Archaeology 6 21-28. 

The use of pesticides in agriculture does not inevitably mean that food residues will result. In many cases, pesticides are applied to non-food agricultural crops, while in other instances pesticides may be applied around, but not directly on, food crops, such as the case in which a broad-spectrum herbicide is used. Even when pesticides are applied directly to food crops, food residues are often not detected. In some cases, pesticides may be applied prior to the development of edible portions of the crop, while in others the rapid environmental degradation of the pesticide between the time of application and the time of harvest may also avoid food residues. 

When the normal use of a pesticide on a food crop may pose the potential to leave a food residue, the EPA establishes a tolerance. The tolerance represents the maximum level of a pesticide residue allowed on the food crop. Tolerances are pesticide and crop specific different crops may have different tolerance levels for a particular pesticide, while a particular crop may have different tolerance levels for the different pesticides that may be used on it. 

Tilgner, D.J. and Daun, H. (1969). Polycyclic aromatic hydrocarbons (polynuclears) in smoked foods. Residue Rev., 27, 19 1. 

Until 1994 the EPA regulated pesticides proposed for use on food crops under certain sections of the Food, Drug, and Cosmetics Act. Carcinogenic pesticides were subject to the Delaney clause, and were thus prohibited. The use of a non-carcinogenic pesticide was allowed if its manufacturer provided data sufficient to establish an RfD, and information on expected food residue levels sufficient to document that the RfD would not be exceeded when people consumed food containing residues of the pesticide. The tool for determining compliance with this criterion is called a tolerance, and it is expressed as the maximum amount of a pesticide that can be present in a given amount of food, if the RfD is not to be exceeded. 

J. F. Pirisino, in J. F. Lawrence (Ed.), Food Constituents and Food Residues, Their Chromatographic Determination, Dekker, New York, 1984, pp. 159-193. 

Food residues intake intake Relative intake concn... 

Food Constituents and Food Residues Their Chromatographic Determination, edited by James F. Lawrence... 

Electrochemical immunosensing of food residues by affinity biosensors and magneto sensors... 

Contamination of food, food residues, and food safety... 

Electrochemical immunosensing of food residues 22.1.2 Pesticides and drug residues detection methods... 

The monitoring of the residues in foods is often at the microgram per kilogram level or lower and has to be supported by strict analytical quality-control standards, so that the analysis produces unequivocal, precise, and accurate residue data. An analytical method to be used in food residues determination should accomplish an adequate specificity, sensitivity, linearity, accuracy, and precision at the relevant residue concentration and in appropriate food matrices. 

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