Investigation of the distribution of deoxynivalenol and ochratoxin A contamination within a 26 t truckload of wheat kernels

Abstract

A study was conducted to determine the distribution of deoxynivalenol (DON) and ochratoxin A (OTA) in a lot of 261 of wheat kernels. Within this study, two different sampling and sample preparation strategies were carried out. On the one hand, following the official commission regulation 401/2006/EC, an aggregate sample out of 100 incremental samples was build, homogenized and prepared for laboratory analysis. On the other hand each individual subsample was investigated for its deoxynivalenol and ochratoxin A content. The determined concentration of DON in the individual samples was in a range from 830 up to 2655 (μg/kg, for OTA results ranged from < 0.2 up to 8.6 μg/kg. Thus, a coefficient of variance of 25% for DON and 200% for OTA was achieved. From this, a spot formation for OTA was observed and the average value of the 100 incremental samples did not correspond to the achieved value for the aggregate sample. While the DON contamination at this concentration range seems to be more even, consequently the result of the aggregate sample was in accordance with the average value.In addition a sample communition study was performed to answer the question whether the time consuming process of grinding of the whole aggregate sample is necessary or not. The results of this study show that contamination of whole wheat kernels with DON is at the same level within a 1 kg sample (CV 16%), while OTA contamination shows high variability (CV 94%). At least for OTA this study indicated that an extensive and complete sample communition of the high volume aggregate sample is necessary.

Quantitative estimation of sampling uncertainties for mycotoxins in cereal shipments

“…increase the slug extent u), a fact that was noted by Biselli et al (2008) who discussed the benefits of blending OTA slugs for reducing sampling variance due to spatial heterogeneity. We also note from Figure 2 that the lesser the number of slugs, the more critical the choice of sampling conditions.…”

“…This random occurrence of mycotoxins is extreme in the case of ochratoxin A (OTA Biselli et al (2008) reported evidence of high DH as they showed that the OTA assay of the final composite sample did not agree with the sublot averages during manual sampling a 26 t truckload of wheat. To some extent this problem is comparable to the sampling of nuggetty materials such as gold ore or the ore of precious stones.…”

Dois planos de amostragem para análise de fumonisinas em milho

“…A maior fonte de variação dos resultados das concentrações de fumonisinas para ambos os planos de amostragem foi na etapa de amostragem, sendo que as variâncias foram três vezes menores (P<0,01) para a amostragem automática em grãos moídos em relação à amostragem manual em grãos inteiros (Tabela 2). Pesquisadores concluíram que a etapa de amostragem é a maior fonte de variabilidade associada ao procedimento de detecção de: fumonisinas em milho (WHITAKER et al, 1998(WHITAKER et al, , 2007; aflatoxinas em milho (WHITAKER et al, 1979;JOHANSSON et al, 2000); aflatoxinas em amendoim (WHITAKER et al, 1994); aflatoxinas em avelã (OZAY et al, 2006), deoxinivalenol e ocratoxina A em trigo (BISELLI et al, 2008 Neste trabalho, foi assumido que as diferenças observadas nos valores do CV entre as amostras de cada lote estavam associadas ao procedimento de amostragem, uma vez que os procedimentos de preparo das amostras e de análise empregados foram os mesmos. Os resultados dos CV das concentrações de fumonisinas dos 11 lotes indicam que o CV da amostragem automática, com média de 6,37%, foi menor (P<0,01) que o CV da amostragem manual, com média de 8,94%.…”

Mycotoxins in food – how to prevent and what to do when things go bad

“…The heterogenic distribution is one of the main problems in mycotoxin contamination assessment. To be able to properly assess the mycotoxin contamination, proper sampling has to be performed, usually combining several subsamples (according to the EU commission guide EC 401/2006 if the batch is larger than 50 tones, the sublots needs to be created, and from each sublot 100 E3S Web of Conferences 215, 01004 (2020) BFT-2020 https://doi.org/10.1051/e3sconf/202021501004 incremental samples per 100 g need to be combined to a total weight of 10 kg of the sample) [42]. To ensure the microbial stability of the foods without the usage of thermal methods, gamma irradiation can be used (γ-rays) usually up to 10 MeV.…”