An alternative to slurry mixing to minimise sample preparation variance for determination of ochratoxin A in wheat
In: World Mycotoxin JournalSearch for other papers by T. Nowicki in
Current site
Google Scholar
Search for other papers by M. Roscoe in
Current site
Google Scholar
Many countries have established maximum limits for ochratoxin A (OTA) in cereal grains and implemented surveillance programs for OTA in wheat shipments. For shipment to some countries, certification for OTA content is mandatory. These control activities require the capability to measure OTA in bulk grain shipments with accuracy and precision. It is known that the nugget effect caused by the heterogeneous nature of mycotoxin contamination in agricultural commodities creates major challenges for generating representative test results due to the potential for high variances in the sampling / sample preparation phases of the analytical process. The water-slurry mixing approach to sample preparation has greatly minimises variances associated with this phase of the analytical process, but this is not a practical technique for all laboratories. The potential magnitude of variances for subsampling raw and ground grain for the dry-milling approach to sample preparation and the means for reducing variances to acceptable levels is not fully understood. We investigated the repeatability of OTA measurements in 2 kg laboratory samples subsampled from 20 kg samples of raw wheat and in 100 g test portions subsampled from 2 kg of ground wheat. In addition, the effect of mixing time on the repeatability of OTA results was investigated prior to subsampling to obtain test portions for analysis. Results show that for subsampling of a primary sample of raw wheat using a conventional sample divider the variability of OTA results decreases with increasing weight of the laboratory sample relative to the weight of the primary sample. In order to improve repeatability, the proportion of primary sample separated out to produce a laboratory sample should be as large as operationally feasible and ideally about 50% of the weight of the primary sample. Four factors are identified for separating out a test sample from a raw wheat laboratory sample.
Purchase
Buy instant access (PDF download and unlimited online access):
Institutional Login
Log in with Open Athens, Shibboleth, or your institutional credentials
Personal login
Log in with your brill.com account
-
Birzele, B., Prange, A. and Kramer, J., 2000. Deoxynivalenol and ochratoxin A in German wheat and changes of level in relation to storage parameters. Food Additives and Contaminants 17: 1027-1035.
'Deoxynivalenol and ochratoxin A in German wheat and changes of level in relation to storage parameters ' () 17 Food Additives and Contaminants : 1027 -1035 .
-
Biselli, S., Persin, C. and Syben, M., 2008. Investigation of the distribution of deoxynivalenol and ochratoxin A contamination within a 26 t truckload of wheat kernels. Mycotoxin Research 24: 98-104.
-
Codex Alimentarius Commission (CAC), 2009. Codex general standard for contaminants and toxins in food and feed (codex stan 193-1995) Available at: http://www.codexalimentarius.net/download/standards/17/CXS_193e.pdf
-
European Commission (EC), 2006. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union L 364: 5-24.
-
Johansson, A.S., Whitaker, T.B., Hagler Jr., W.M., Giesbrecht, F.G., Young, J.H. and Bowman, D.T., 2000. Testing shelled corn for aflatoxin. Part I: Estimation of variance components. Journal of AOAC International 83: 1264-1269.
'Testing shelled corn for aflatoxin ' () 83 Part I: Estimation of variance components. Journal of AOAC International : 1264 -1269 .
-
Langseth, W., Ellingsen, Y., Nymoen, U. and Okland, E.M., 1989. High-performance liquid chromatographic determination of zearalenone and ochratoxin A in cereals and feed. Journal of Chromatography 478: 269-274.
-
Scholten, J.M. and Spanjer, M.C., 1996. Determination of aflatoxin B1 in pistachio kernels and shells. Journal of AOAC International 79: 1360-1364.
'Determination of aflatoxin B1 in pistachio kernels and shells ' () 79 Journal of AOAC International : 1360 -1364 .
-
Scudamore, K.A., Banks, J. and MacDonald, S.J., 2003. Fate of ochratoxin A in the processing of whole wheat grains during milling and bread production. Food Additives and Contaminants 20: 1153-1163.
'Fate of ochratoxin A in the processing of whole wheat grains during milling and bread production ' () 20 Food Additives and Contaminants : 1153 -1163 .
-
Spanjer, M.C., Scholten, J.M., Kastrup, S., Jorissen, U., Schatzki, T.F. and Toyofuku, N., 2006. Sample comminution for mycotoxin analysis: dry milling or slurry mixing. Food Additives and Contaminants 23: 73-83.
'Sample comminution for mycotoxin analysis: dry milling or slurry mixing ' () 23 Food Additives and Contaminants : 73 -83 .
-
Van Egmond, H.P. and Jonker, M.A., 2004. World regulations for mycotoxins in food and feed in 2003. FAO Food and Nutrition Paper 81. FAO, Rome, Italy.
-
Velasco, J. and Morris, S.L., 1976. Use of water slurries in aflatoxin analysis. Journal of Agricultural and Food Chemistry 24: 86-88.
'Use of water slurries in aflatoxin analysis ' () 24 Journal of Agricultural and Food Chemistry : 86 -88 .
-
Vicam, 2010. About OchraTest. Available at: http://www.vicam.com/products/ochratest.html
-
Whitaker, T.B., 1977. Sampling granular foodstuffs for aflatoxin. Pure and Applied Chemistry 49: 1709-1717.
'Sampling granular foodstuffs for aflatoxin ' () 49 Pure and Applied Chemistry : 1709 -1717 .
-
Whitaker, T.B. and Dickens, J.W., 1974. Variability of aflatoxin test results. Journal of the American Oil Chemists' Society 51: 214-218.
'Variability of aflatoxin test results ' () 51 Journal of the American Oil Chemists' Society : 214 -218 .
-
Whitaker, T.B. and Dickens, J.W., 1980. A water slurry method of extracting aflatoxin from peanuts. Journal of the American Oil Chemists' Society 57: 269-272.
'A water slurry method of extracting aflatoxin from peanuts ' () 57 Journal of the American Oil Chemists' Society : 269 -272 .
-
Whitaker, T.B., Trucksess, M., Johansson, A.S., Giesbrecht, F.G., Hagler Jr., W.M. and Bowman, D.T., 1998. Variability associated with testing corn for fumonisin. Journal of AOAC International 81: 1162-1168.
'Variability associated with testing corn for fumonisin ' () 81 Journal of AOAC International : 1162 -1168 .
-
Whitaker, T.B., Hagler Jr., W.M., Giesbrecht, F.G. and Johansson, A.S., 2000. Sampling, sample preparation and analytical variability associated with testing wheat for deoxynivalenol. Journal of AOAC International 83: 1285-1292.
-
Whitaker, T.B., Hagler Jr., W.M., Giesbrecht, F.G. and Johansson, A.S., 2002. Sampling wheat for deoxynivalenol. In: DeVries, J.W., Trucksess, M.W. and Jackson, L.S. (eds.) Mycotoxins and food safety. Kluwer Academic/Plenum Publishers, New York, NY, USA, pp. 73-83.
-
Whitaker, T.B., 2003. Standardization of mycotoxin sampling procedures: an urgent necessity. Food Control 14: 233-237.
'Standardization of mycotoxin sampling procedures: an urgent necessity ' () 14 Food Control : 233 -237 .
| All Time | Past 365 days | Past 30 Days | |
|---|---|---|---|
| Abstract Views | 110 | 36 | 8 |
| Full Text Views | 10 | 0 | 0 |
| PDF Views & Downloads | 8 | 0 | 0 |
An alternative to slurry mixing to minimise sample preparation variance for determination of ochratoxin A in wheat
In: World Mycotoxin JournalSearch for other papers by T. Nowicki in
Current site
Google Scholar
PubMed
Search for other papers by M. Roscoe in
Current site
Google Scholar
PubMed
Many countries have established maximum limits for ochratoxin A (OTA) in cereal grains and implemented surveillance programs for OTA in wheat shipments. For shipment to some countries, certification for OTA content is mandatory. These control activities require the capability to measure OTA in bulk grain shipments with accuracy and precision. It is known that the nugget effect caused by the heterogeneous nature of mycotoxin contamination in agricultural commodities creates major challenges for generating representative test results due to the potential for high variances in the sampling / sample preparation phases of the analytical process. The water-slurry mixing approach to sample preparation has greatly minimises variances associated with this phase of the analytical process, but this is not a practical technique for all laboratories. The potential magnitude of variances for subsampling raw and ground grain for the dry-milling approach to sample preparation and the means for reducing variances to acceptable levels is not fully understood. We investigated the repeatability of OTA measurements in 2 kg laboratory samples subsampled from 20 kg samples of raw wheat and in 100 g test portions subsampled from 2 kg of ground wheat. In addition, the effect of mixing time on the repeatability of OTA results was investigated prior to subsampling to obtain test portions for analysis. Results show that for subsampling of a primary sample of raw wheat using a conventional sample divider the variability of OTA results decreases with increasing weight of the laboratory sample relative to the weight of the primary sample. In order to improve repeatability, the proportion of primary sample separated out to produce a laboratory sample should be as large as operationally feasible and ideally about 50% of the weight of the primary sample. Four factors are identified for separating out a test sample from a raw wheat laboratory sample.
| All Time | Past 365 days | Past 30 Days | |
|---|---|---|---|
| Abstract Views | 110 | 36 | 8 |
| Full Text Views | 10 | 0 | 0 |
| PDF Views & Downloads | 8 | 0 | 0 |
