Food surveys

Composite sampling is a way of reducing the cost of analysing large numbers of samples. A composite sample consists of two or more portions of material (collected at the same time) selected so as to represent the material being investigated. The ratio of components taken to make up the composite can be in terms of bulk, time or flow. The components of the composite sample are taken in proportion to the amount of the material that they represent. This type of sample may be appropriate when carrying out food surveys. The samples may, for example, be bulked in proportion to the amount normally consumed. 

Importantly, past and present human exposure to PCDD/PCDFs and PCBs results primarily from their transfer along the pathway atmospheric emissions air deposition -> terrestrial/aquatic food chains - human diet. Information from food surveys in industrialized countries indicates a daily intake of PCDD/PCDFs on the order of 50-200 pg I-TEQ/person per day for a 60 kg adult, or 1-3 pg I-TEQ/kg bw per day. If dioxin-like PCBs are also included, the daily total TEQ intake can be higher by a factor of 2-3. Recent studies from countries that started to implement measures to reduce dioxin emissions in the late 1980s clearly show decreasing PCDD/PCDF and PCB levels in food and, consequently, a lower dietary intake of these compounds by almost a factor of 2 within the past 7 years. 

MAFF (1996) Ministry of Agriculture, Fisheries and Food. Survey of plasticizer levels in food contact materials and in foods. Food Surveillance Papers No 21, UK... 

ESA (2006) Eluorinated chemicals - UK dietary intakes. Food Survey Information Sheet No. 11/06. Eood Standards Agency, UK... 

MAFF (Ministry of Agriculture, Food and Fisheries), Household Food Consumption and Expenditure. Annual Report of the National Food Survey Committee. London HMSO, 1996. 

U.S. Department of Agriculture and CSFII, A. R. S. (1994-1996). Food Surveys Research Group Home Page. www.sun.ars-rin.gov/ars/Beltsville/barc/bhnrc/foodsurvey/home. 

The UK Total Diet Study (TDS) relies on nationally representative information about the average food consumption by individual households researched in the UK National Food Survey (based on a survey of approximately 7000 households).2,3 Typical diets are constructed based on these data. Foodstuffs are purchased from retail outlets, then prepared and cooked in the normal manner. The individual foodstuffs are then usually combined into various groups of similar foods - for example cereals, green vegetables and fish - in the proportions eaten on average by consumers. Population dietary exposures can then be calculated using data from the TDS samples. 

Food Standards Agency, UK, 2003. Dioxins and dioxin-like PCBs in the UK diet 2001 total diet study samples. Food Survey Information Sheet 38/03. 

Schecter A, Cramer P, Boggess K, et al. 1996c. Dioxin intake from U.S. Food Results from a new nationwide food survey. In Organohalogen Compounds volume 28. 

USDA (1997a) Design and operation continuing survey of food intakes by individuals 1994-96. Food Survey Research Group, Agricultural Research Service (ARS), United States Department of Agriculture. 

Food Standards Agency, 2003, Food Survey Information Sheet Number 34/03, January 2003, Mineral Hydrocarbons in Food Contact Materials. 

Ministry of agriculture. Househid food consumption and expenditure. Annual reports of the national Food Survey committee. London HMSO 1990, 1961-90. 

The 5-cis, 9-cis and 15-di-isomers of lycopene have been assayed in various foods and in human tissues using nuclear magnetic resonance (NMR) spectroscopy (Zumbrunn et al., 1985). In the various tomato-based foods surveyed by Schierle et al. (1996), the all-trans isomer represented between 35% to 96% of the total lycopene. In their survey, the proportion of 5-di-isomer in tomato products ranged from 4% to 27%, with considerably lower amounts of the other di-isomers. In human serum and tissues, the di-isomers of lycopene were found to contribute more than 50% of total lycopene (Krinsky et al., 1990). 

FAO. (1952). Food and Agr. Organization U. N., Rome, 2nd World Food Survey. 

Pennington JA, Young BE, Wilson DB, et al. 1986. Mineral content of foods and total diets The selected minerals in foods survey, 1982 to 1984. J Am Diet Assoc 86 876-891. 

Based on dietary assessment data for energy and fat (Food Surveys Research Group, 2005), SBO accounts for about 12% of calories in the average American diet. Given the contribution of SBO to the diet, this chapter discusses the health effects of SBO and its constituent fatty acid profile, as well as soy protein and its bioactive components. 

Food Surveys Research Group. Intakes of 19 individualfatty acids Results from the 1994—1996 Continuing Survey of Food Intakes by Individuals. 2005 http //www.ars.usda.gov (20 August 2007). 

The intake of iodized salt by this program was estimated to be around 4g/day, and the iodization level was set to 13 ppm. Bread is a staple food in Denmark, and simulation studies performed by the Danish National Food Agency based on Danish food surveys had shown that iodized salt in bread, in combination with iodized table salt, would distribute the iodine nearly as evenly in the population as iodization of all salt used by the food industry. 

Ritson, C. and Hutchins, R. (1991) The consumption revolution. In Slater, J.M. (ed.) Fifty Years of the National Food Survey. The Stationery Office, London. UK, pp. 35-46. 

Australia submitted a report from the Department of Health (Government of Western Australia, 2005), with ooourrenoe data for 109 individual samples of different nut samples prepared as ready-to-eat, for almond (19), Brazil nut (3), cashew (9), chestnut (4), hazelnut (15), macadamia (22), pecan (3), pine (3), pistachio (15) and walnut (16), based on food surveys of AFL conducted in 2003 and 2004. Sixteen per cent of these samples had quantified levels of AFL AFL levels ranged between not deteoted (<2 pg/kg) and 11 pg/kg, with no level in excess of the 15 pg/kg limit in Australia. 

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