World Grain - October 2015 - 94

TECHNICAL PROFILE: STAYING IN CONTROL OF MYCOTOXINS

Mycotoxin concentration relative to input (%)
100
100
100

Input corn

638

Dust

1200
419
253
214

Brokens

390
183

Low density

369
332
272

Reject SORTEX

529
135

Cleaned corn

18
12
31

DON
ZEA
FB1 + FB2

Mycotoxin concentrations of input corn (base level of 100% for DON, ZEA,
and FB1+FB2) and the relative concentrations in the corn fractions which
were removed by the sequential processing steps and for the cleaned corn.
The reduction performance is case specific and may vary for different types
of contamination. The sampling was in accordance with the E.U. Commission
Regulation No 401/2006. Mycotoxin analysis was carried out using HPLC.

of hazardous grains early in the value chain - not only in mills
but also at grain elevator/reception facilities and warehouses.
CASE STUDIES SHOW CONSISTENT TOXIN REDUCTION
In 2012, The Bühler Group worked with Italian processors
and leading scientists to successfully demonstrate that dediFDWHGP\FRWR[LQFOHDQLQJOLQHVFDQHIIHFWLYHO\UHGXFHDÀDWR[LQ
B1 levels in contaminated corn lots - consistently below the
European maximum level for feed of 20 parts per billion (ppb).
Two years later, the mycotoxin problem hit the same reJLRQ DJDLQ WKLV WLPH VKLIWLQJ IURP DÀDWR[LQV SURGXFHG E\
Aspergillus species, to DON, produced by Fusarium species.
$OWKRXJKOHVVWR[LFWKDQDÀDWR[LQVSURGXFHUVZHUHRQDOHUW
not to exceed maximum permitted levels of DON in product
intended for food and to ensure they complied with commerFLDOVSHFL¿FDWLRQVDQGJXLGDQFHOHYHOVIRUXVHLQDQLPDOIHHG
Reliable measurement of a mycotoxin concentration at ppb and
ppm requires a statistically representative sample of the product,
sample preparation, for example, by grinding and extraction, followed by chemical analysis using test kits or laboratory-based
methods, such as high performance liquid chromatography
(HPLC). Clearly, this approach is simply not viable for a grain
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key physical indicators of the presence of fungal contamination, and removing kernels with these indicators by cleaning
DQGRSWLFDOVRUWLQJLWLVSRVVLEOHWRVLJQL¿FDQWO\UHGXFHP\FRtoxin concentration.
%XW ¿UVW D FHQWUDO TXHVWLRQ WR DGGUHVV LV ZKHWKHU WKLV DSproach remains valid even when multiple mycotoxins are
present and the indicating properties change, due to vary94

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Institute of Sciences of Food Production ISPA, Bari, Italy, at
DQ,WDOLDQJUDLQUHFHSWLRQIDFLOLW\,WFRQ¿UPVWKHUHVXOWVSUHYLRXVO\REWDLQHGIRUDÀDWR[LQ%IRUWKHP\FRWR[LQV'21
ZEA, and fumonisins B1 and B2, which co-occurred at different levels in the investigated corn lots.
The study proves:
x Broken kernels tend to foster higher contamination
with levels ranging from 250%-400% of the respective mycotoxin, relative to the input concentration.
7KLVPHDQVVHSDUDWLRQE\VL]HLVDQHVVHQWLDO¿UVWVWHS
in lowering mycotoxin levels.
x Light product and dust from affected lots typically
contain high levels of mycotoxins. This study highlighted increased concentrations of up to 1,200% of
ZEA. Integrated or separate air aspiration systems can
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lower-density grains, with noted levels of up to 180%370% for the three different mycotoxins, decreases
concentration to even lower levels.
x Color defects are strongly associated with mycotoxin contamination. An advanced optical sorter targets
color defects effectively and with minimal removal of
good product. In the current study, relative levels of
272% and 529% have been measured in the rejected
product for DON and ZEA, respectively.
The study concluded that the mycotoxin concentration of
the cleaned product was reduced to 12%-31% of the initial
concentration and revealed that all removed material had high
concentrations of all three monitored mycotoxins. SORTEX
optical sorting demonstrated outstanding selectivity in the removal of contaminated whole kernels.
It is this in-depth understanding of the key indicators of fungal contamination that has allowed Bühler experts to design
VWDQGDUGÀRZVKHHWVIRUP\FRWR[LQUHGXFWLRQOLQHVIRUGLIIHUHQW JUDLQV DQG FRQWDPLQDWLRQV$V WKH FRQWDPLQDWLRQ SUR¿OH
and thus the indicators for a fungal infection may vary, it is
essential to have a solid line of defense in place, which sequentially targets all relevant indicators of mycotoxins.
Bühler mycotoxin reduction lines are designed to help
ensure a consistent and safe output quality, despite challenges imposed by natural variability and emerging hazards,
enabling continued business success for grain processors.
Several customer installations, at both grain reception facilities and mills, are already proving successful and demonstrating that return on investment can be achieved in less
than a year.
Matthias Graeber is a mycotoxin expert with the Bühler Group, based in
London, U.K. He can be reached at matthias.graeber@buhlergroup.com.
We want to hear from you - Send comments and inquiries to worldgrain@
sosland.com. For reprints of WG articles, e-mail reprints@sosland.com.

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