Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: Progress Report: (a) Continued to measure the variability associated with the sampling, sample preparation, and analytical steps associated with measuring ochratoxin A (OTA) in wheat and oats. Using regression analysis, the variances for all three steps were shown to be a function of the OTA concentration. The observed distribution among sample test results is being compared to several theoretical distributions for model development. (b) Determined the variance and aflatoxin (AFT) distribution among samples test results taken from contaminated lots of dried figs which led to the development of a Codex Standard that harmonized sampling plans and maximum limits for AFT in dried figs traded in the international market. (c) Compared AFT sample test results when peanut samples are ground using two different mills approved by USDA/AMS to prepare peanut sample for aflatoxin analysis. Using AFT test results from the two mills and Monte Carlo simulation, the performance of the two mills was evaluated and no biases were found with either mill. (d) Assisted the US FDA determine the accuracy and precision associated with five commercial kits used to measure egg, peanut, and milk proteins in both a sugar cookie and chocolate matrices. Results indicated that recovery and precision decreased as bake time and temperatures increased. (e) Continued development of EXCEL software for public use that calculates operating characteristic (OC) curves to predict the performance of mycotoxin sampling plan designs for 25 different mycotoxin/commodity combinations. PARTICIPANTS: Andrew B. Slate - NC State University; Canadian National Millers Association; Tubutak Research Center - Turkey; Ms Darlene Cowart - Birdsong Peanut Co; Kristin Williams - US FDA TARGET AUDIENCES: Canadian Millers; Health Canada; International Fig industry; Codex Committee on Contaminants in Foods; US FDA; US Peanut Industry; USDA/AMS PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Impact: (a) Health Canada is considering the establishment of maximum level (ML) for OTA in raw wheat and oats marketed in domestic and export markets. With the establishment of an OTA ML for wheat and oats, OTA sampling plans will have to be designed to determine if wheat and oat lots meet the established ML. From the variance and distributional information among sample test results, OTA sampling plans can be designed to minimize the number of contaminated lots reaching the consumer and minimize the financial burden to buyers and sellers associated with misclassifying lots according to their OTA concentration. (b) From variance and distributional information among AFT sample test results for died figs, a Codex Standard was developed when an aflatoxin ML and sampling plan to was accepted by Codex to detect AFT in dried figs traded in the international market. The harmonization of the AFT ML and sampling plans will increase consumer protection and improved world trade. (c) Two USDA/AMS mills, most commonly used to comminute official peanut samples provided analytical samples that gave similar AFT test results. These results demonstrated that concerns among shellers and food manufacturers that samples prepared with these two mills didn't give similar results was not true. This allows USDA/AMS, shellers, and food manufacturers to use either mill without fear that there is an inherent bias associated with the official USDA subsampling mill affecting AFT results. (d) It is important to accurately and precisely determine egg, peanut, and milk proteins in food products since they can cause sever allergic reactions in individuals. The results demonstrated to the FDA that there is a need to improve the performance of commercially available test kits in order to protect the consuming public from proteins that can cause allergic reactions. (e) A method was developed based upon experimental measurements of the variability and distribution among sample test results to evaluate the performance of mycotoxin sampling plans by predicting the good lots rejected and bad lots accepted by a sampling plan design for 25 mycotoxin/commodity combinations. Because the mathematics and computer software is complicated, an EXCEL based program is currently being developed for public use where they can input basic information about the sampling plan design into the software and the software will predict the performance of the specific mycotoxin sampling plan for anyone of these 25 mycotoxin/commodity combinations.
Publications
- Publications: Khuda, S., Slate, A., Pereira, M., Al-Taher, F., Jackson, L., Diaz-Amigo, C., Bigley III, E., Whitaker, T., and Williams, K. 2012. Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: Sugar cookies. Agricultural and Food Chemistry, 60:4195-4203.
- Khuda, S., Slate, A., Pereira, M., Al-Taher, F., Jackson, L., Diaz-Amigo, C., Bigley III, E., Whitaker, T., and Williams, K. 2012. Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: Dark chocolate. Agricultural and Food Chemistry, 60:4204-4211.
- Whitaker, T.B. and Slate, A.B. 2012. Comparing the USDA/AMS subsampling mill to a vertical cutter mixer type mill used to comminute shelled peanut samples for aflatoxin analysis. Peanut Science, 39:69-81.
- Whitaker, T.B. and Slate, A.B. 2012. Sampling and sample preparation for mycotoxin analysis, In: Guide to Mycotoxin, Eds: E.M. Binder and R. Krska. Anytime Publishing Services, Leicestershire, England, pp 55-87 (Book Chapter).
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: Progress Report: (a) Developed an experimental protocol for the Canadian National Millers Association to measure the variance and ochratoxin A (OTA) distribution among samples test results taken from contaminated lots of Canadian wheat and oats. (b) Developed an experimental protocol for the Codex Committee on Contaminants in Foods (CCCF) and the government of Turkey to measure the variance and aflatoxin (AFT) distribution among samples test results taken from contaminated lots of dried figs. (c) Developed a Monte Carlo model to simulate the performance of the sample preparation methods for peanut samples using two different mills to comminute the samples for AFT testing. (d) Continued development of an EXCEL software to calculate operating characteristic (OC) curves to predict the performance of sampling plan designs for 25 different mycotoxin/commodity combinations. PARTICIPANTS: Dr. Francis Giesbrecht, Professor emeritus, Dept. of Statistics, NCSU Mr. Andrew B. Slate, Biological and Agricultural Engineering Dept., NCSU Canadian National Millers Association, Ottawa, Canada Dr. Hayrettin Ozer, Tubitak Research Center, Turkey TARGET AUDIENCES: Consumers, grain industry, fig industry, peanut industry, food manufacturers, and regulatory agencies PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Impact: (a) Health Canada is considering the establishment of maximum level (ML) for OTA in raw wheat and oats marketed in the food chain. With the establishment of an OTA ML for wheat and oats, OTA sampling plans will have to be designed to determine if wheat and oat lots meet the established ML. From the variance and distributional information among sample test results, OTA sampling plans can be designed to minimize the number of contaminated lots reaching the consumer and minimize the financial burden to the industry associated with misclassifying lots according to their OTA concentration. (b) An objective of CCCF is to harmonize MLs and sampling plan designs for testing AFT in dried figs in the export market. From the variance and distributional information among sample test results, AFT sampling plans can be designed to minimize the number of contaminated lots reaching the consumer and minimize the financial burden to the exporter and importer associated with misclassifying lots according to their AFT concentration. (c) Two comminution mills, a USDA subsampling mill and a vertical cutter type mill (VCM), are used by the peanut industry to comminute official USDA peanut samples for AFT testing. There is a concern among shellers and food manufacturers that samples prepared with the USDA mill underestimates the aflatoxin in official samples compared to the use of the VCM. The Monte Carlo model demonstrated that the observation made by shellers and food manufactures was due to the design of the USDA sequential sampling plan and not due to the type mill used to prepare the sample. This allows USDA, shellers, and food manufacturers to use either mill without fear that there is an inherent bias associated with the official USDA subsampling mill affecting AFT results. (d) A method was developed based upon experimental measurements of the variability and mycotoxin distribution among sample test results to calculate an OC curve and predict the good lots rejected and bad lots accepted by a sampling plan design. Historically, about 25 different mycotoxin/commodity sampling studies have been conducted. Because the mathematics and computer software is complicated, it is difficult for food industries, government agencies and international organizations to calculate OC curves and design mycotoxin sampling plans. An EXCEL based program is currently being developed where users can input basic information about the sampling plan design into the software and the software will output the OC curve along with other information about the performance of specific sampling plan designs.
Publications
- Vargas, E.A., dos Santos, E.A., Whitaker, T.B., and Slate, A.B. 2011. Determination of aflatoxin risk components for in-shell Brazil nuts. Food Additives and Contaminants, 28:1242-1260.
- Shephard, G.S., Berthiller, F., Burdaspal, P., Crews, C., Jonker, M.A., Krska, R., MacDonald, S., Malone, B., Maragos, C., Sabino, M., Solfrizzo, M., Van Egmond, H.P., and Whitaker, T.B. 2011. Developments in mycotoxin analysis: an update for 2009-20010. World Mycotoxin Journal, 4:3-28.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: (a) Designed aflatoxin sampling plans for the US pistachio and almond tree nut industries for lot exported to the EU. (b) Developed a method to predict in advance the percent lots rejected when lots are re-testing at a later date in the EU using the percents lots rejected in the US. (c) Measured the sampling and analytical variability associated with the test procedure used to measure aflatoxins (AF) and ochratoxin A (OTA) in two bulk lots consisting of one-lb bags of powdered ginger using a 5 g laboratory sample and HPLC analytical methods. (d) As part of a Codex effort, evaluated the performance of several fumonisin sampling plan designs for maize and maize products traded in the export market. PARTICIPANTS: Mr. Andrew B. Slate - Biological and Agricultural Engineering Dept, NCSU; Dr. Francis Giesbrecht - Professor Emeritus Dept of Statistics, NCSU; Ms Julie Adams, Almond Board of California, Modesto, CA; Dr. Robert Klien, Administrative Board for Pistachios, Fresno, CA; Dr. Mary Trucksess, US FDA, Washington, DC; Dr. Carlo Brera, Italian Institute of Health, Rome, Italy. TARGET AUDIENCES: Development of sampling statistics will help regulatory agencies such as US FDA and food industries design mycotoxin sampling plans that will improve consumer safety by reducing contamination in the supply chain and improve trade. Results of research are directed specifically to the California pistachio and almond industries, US FDA, European Commission, and Italian Institute of Health. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
(a) Using the export market system model, aflatoxin sampling plans were designed for the US pistachio and almond industries to keep lots rejected in the EU below the EU threshold of 6% and reduce costs associated with returning rejected lots from the EU back to the US. The EU, who is the largest importer of US almond and pistachio lots, modified in March 2010 their aflatoxin maximum limits and sampling plans to closely match Codex maximum limits and sampling plans for tree nuts. The EU tests US lots for aflatoxin at import to verify that US lots meet EU aflatoxin regulatory limits. If the percent US lots rejected at destination by the EU exceed 5 to 6% of lots tested, the EU will impose tighter testing protocols where they could test up to 100% of imported lots. If the EU goes to tighter control more US lots will be rejected in the EU at considerable expense to the US industry and affect the consistency of supply for EU buyers. (b) Because of the time delay between testing tree nut lots in the US and in the EU, it is often too late to tighten inspection in the US to minimize the percent lots rejected in the EU. A method was developed that uses the percent lots rejected in the US to predict the percent lots that will be rejected in the EU some months later. The US can tighten inspection and keep lots rejected in the EU to a minimum which will provide large savings to the tree nut industries. (c) Because of the variability among replicate sample test results taken from the same lot, it is difficult to get an accurate estimate of the true mycotoxin contamination in a bulk lot. Equations can be used to show the effect of increasing laboratory sample size and/or number of aliquots on reducing the variability of the test procedures used to estimate OTA and AF in powdered ginger, which will help regulatory agencies design the most effective sampling plans for available resources. (d) Because over 100 countries have differing aflatoxin limits and sampling plans for foods, Codex Committee for Contaminants in Foods (CCCF) initiated a program to promote export trade and increase consumer safety by harmonizing mycotoxin maximum limits and sampling plans for commodities traded in the international markets. Fumonisin sampling plans for maize and maize products with varying limits and sample sizes were evaluated for consideration by members of CCCF in The Hague in April 2010. Harmonized mycotoxin limits and sampling plans will result in less disruption in supply to processors, lower costs for exporter due to fewer lot rejections, and provide a safer food supply for the consumer.
Publications
- Shephard, G.S., Berthiller, F., Dorner, J., Krska, R., Lombert, G.A., Malone, B., Maragos, C., Sabino, M., Solfrizzo, M., Trucksess, M., Van Egmond, H.P., and Whitaker, T.B. 2010. Developments in mycotoxin analysis: an update for 2008-2009. World Mycotoxin Journal, 3:3-23
- Whitaker, T.B., Slate, A.B., Adams, J.G., Birmingham, T., and Giesbrecht, F.G. 2010. Comparing the performance of sampling plans that use a single regulatory limit based upon total aflatoxins to sampling plans that use dual limits based upon B1 and total aflatoxins. World Mycotoxin Journal, 3:35-44.
- Whitaker, T.B., Slate, A.B., Birmingham, T., Adams, J., Jacobs, M., and Gray, G. 2010. Correlation between aflatoxin contamination and various USDA grade categories for shelled almonds. J. AOAC, Int., 93:943-947.
- Whitaker, T.B., Slate, A.B.., Adams, J., and Birmingham, T. 2010. Number of export almond lots rejected in the EU due to USA sampling plans and aflatoxin contamination levels among lots tested. World Mycotoxin Journal, 3:157-168.
- Brera, C., DeSantis, B., Prantera, E., Debegnach, F., Pannunzi, E., Fasano, F., Berdini, C., Slate, A., Miraglia, M., and Whitaker, T.B. 2010. Effect of sample size in the evaluation of In-Field sampling plans for aflatoxin B1 determination in Corn. J. Agricultural and Food Chemistry, 58:841-8489.
- Food and Agriculture Organization of the UN and the International Atomic Energy Agency, 2010. Sampling Procedures to Detect Mycotoxins in Agricultural Commodities, T.B. Whitaker, A.B. Slate, B. Doko, B. Maestroni, and A. Cannavan (Eds), Springer, New York, NY.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: (a) Developed an export market system model to simulate the effects of various US aflatoxin sampling plan designs and crop contamination levels on the number of export lots accepted and rejected at origin in the US and at destination in the EU. Models were developed specifically for both the US pistachio and almond industries who export a large percentage of their crop to the EU. (b) Measured the sampling and analytical variability associated with the test procedure used to measure aflatoxins (AF) and ochratoxin A (OTA) in two bulk lots of powdered ginger using a 5 g laboratory sample and HPLC analytical methods. Equations are derived to show the effect of increasing laboratory sample size and/or number of aliquots on reducing the variability of the test procedures used to estimate OTA and AF in powdered ginger. (c) As part of a Codex effort, evaluated the performance of several aflatoxin sampling plan designs for Brazil nuts traded in the export market. PARTICIPANTS: Statitical support provided by Dr. Francis Giesbrecht, Professor Emeritus, Dept. of Statistics, NCSU. Treenut export problems identified by Almond Board of California and the Pistachio industry. The USDA, FAS and AMS are pardners when study results are communicated between US exporters and EU officials. The need to develop sampling statistics for food supplements was identified by Dr. Mary Trucksess with the FDA, in College Park, MD. Dr. Eugenia Vargas with the Brazil Minister of Agriculture requested support to develop sampling statistics and aflatoxin sampling plans for Codex review. TARGET AUDIENCES: a) Treenut contamination studies will be used by US exporters, FDA, USDA/FAS and AMS, EU importers, and EU regulatory agencies; (b) food supplement contamination studies will be used by the FDA and processors; (b) Brazil nut contamination studies will be used by Brazil Ministry of Agriculture, Brazil treenut industry, US importers, and Codex Committee on Contaminants in Foods. In all cases the information will help remove contaminated food from the market and improve consumer safety. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
(a) The EU is the largest importer of US almond and pistachio lots. The EU tests US lots for aflatoxin at import to verify that the lots meet EU aflatoxin regulatory limits. If the percent US lots rejected at destination by the EU exceed 5 to 6% of lots tested, the EU will impose tighter testing protocols where they could test up to 100% of imported lots. If the EU goes to tighter control more US lots will be rejected in the EU at considerable expense to the US industry and affect the consistency of supply for EU buyers. Therefore the US industries want to use aflatoxin sampling plan designs at origin to keep US rejects below 5 to 6%. The export market system models has been used by the US pistachio and almond industries to design sampling plans to keep rejects below the EU threshold of 6% and reduce costs associated with returning lots rejected in the EU. (b) Because of the variability among replicate sample test results taken from the same lot, it is difficult to get an accurate estimate of the true mycotoxin contamination in a bulk lot. Study results showed how much variability was associated with each step of the aflatoxin test procedure so that regulatory agencies can design the most effective sampling plans for available resources. (c) Because over 100 countries have differing aflatoxin limits and sampling plans for foods, Codex Committee for Contaminants in Foods (CCCF) initiated a program to promote export trade and increase consumer safety by harmonizing aflatoxin limits and sampling plans for almonds, pistachios, hazelnuts, and Brazil nuts. Aflatoxin sampling plans for Brazil nuts with varying limits and sample sizes will be considered by members of CCCF in The Hague in April 2010. Harmonized aflatoxin limits and sampling plans will result in less disruption in supply to processors, lower costs for exporter due to fewer lot rejections, and provide a safer food supply for the consumer.
Publications
- Peterson, G.L., Whitaker, T.B., Stefanski, R.J., Pedleckis, E.V., Phillips, J.G., Wu, J.S., and Martinez, W.H. 2009. A risk assessment model for importation of United States milling wheat containing Tilletia Controversa. Plant Disease, 93:560-573.
- Trucksess M.W., Whitaker T.B., Weaver C.M., Slate A.B., Giesbrecht F.G., Rader J.I., Betz J.M. 2009. Sampling and analytical variability associated with the determination of total aflatoxins and ochratoxin A in powdered ginger sold as a dietary supplement in capsules. J Agric Food Chem, 57:321-325.
- Shephard, G.S., Berthiller, .F, Dorner, J., Krska, R., Lombert, G.A., Malone, B., Maragos, C., Sabino, M., Solfrizzo, M., Trucksess, M. W., Van Egmond, H.P., and Whitaker, T.B. 2009. Developments in mycotoxin analysis: an update for 2007-2008. World Mycotoxin Journal, 2:3-21
- Whitaker, T.B., Trucksess, M.W., Weaver, C.M., and Slate, A.B. 2009. Sampling and analytical variability associated with the determination of aflatoxins and ochratoxin A in bulk lots of powdered ginger marketed in 1-lb bags. Journal Analytical and Bioanalytical Chemistry, 395:1291-1299.
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