Farmers Review Africa Nov-Dec 2018 Farmers Review November-December 2018-6 | Page 21

©PETKUS GROUP
The PETKUS/ROEBER facility in Wutha-Farnroda (Germany) for testing clients’ samples and machine prototypes (source: PETKUS Group).
According to the Department of
Primary Industries and Regional
Development’s Agriculture and Food
Division (DPIRD) in Western Australia,
the annual costs to the industry of wild
oats was estimated to be 80 mill. USD,
and wild oats having the potential to
decrease yields by up to 80%.
Sorting results above the
standard
Optical sorters are doing a great job
where mechanical cleaning reaches
its limits or a specific or high quality
is needed. In addition, weather
conditions or cultivation flaws can
cause field production failure which
can only be offset in some way by
optical sorters. ROEBER can give vast
examples for those rescue operations:
• Deoxynivalenol (DON) level
reduction due to fusarium
infestations to below threshold
limits of 200 µg/kg for baby food
purpose;
• Separating paddy rice kernels with
a red coloured bran from white
•
•
•
•
rice (reduction from 13% to 0.11%
contamination);
Sorting a rye lot with 15%
contamination of triticale to final
0.25% contamination;
Separating durum from soft wheat
for seed or commodity pasta
production;
Removing off-types of sweet corn
originating from commercial sweet
corn volunteers with a final purity
level of target sweet corn grains of
> 99%;
Counting and analysing statistically
the nature and amounts of
defects and impurities in Arabica
coffee beans such as sticks,
cherries, black seeds, pergamino,
fermented seeds etc.
The list for optical sorting applications
is long. The machines became an
integral part of the seed and grain
processing industry. Optical sorters are
often considered as easy to operate
machines which can do all sorting jobs
easily: colour, shape, seed size and
ingredient detection and separation.
Nevertheless, it all depends on the
composition and the material to be
sorted. Sorting results can differ
substantially in purity levels between
crops, but also between varieties.
“You have to be aware that results
can differ even within crop lots or
for all variants”, says Dr. Kai-Uwe
Vieth, Sales and Development
Manager at ROEBER Institut GmbH,
knowing about the influence of input
contamination level, required ratio of
good material in the reject and differing
characteristic traits of varieties.
“Living organisms are too variable per
se.” In addition, high sorting quality or
purity are at the expense of good seed
loss in the reject fraction. The last 1%
of purity costs “accept” kernels.
The development goes on
“Obviously, the sorting results of some
optical sorters on the market are above
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