for the food processing industry
Reworking or Re-Peeling of Mechanically Peeled
for the Catering Sector?
in Batch Peelers or in Roller Peeling Machines?
manual reworking of potatoes, already peeled
mechanically, for the catering sector requires many
personnel, above all if the inspection of the peeled
material is done on conveyor inspection beltes.
Here, the potato lies statically on the belt, and it
is impossible for the human eye to ascertain whether
there are damages or foul spots at its lower (hidden)
side. To make sure this is not the case the staff have
to pick up every potato. - If manual reworking is
carried out on roller inspection belts, it'll take
slightly less time to do the job: You need not pick up
every potato. The peeled potatoes pass the personnel
in constant rotation: The "good" potatoes
keep moving on immediately and are not touched anymore
the performance of the personnel appears to be
insufficient if after a first peeling process at e.g.
a waste percentage of 20 to 25 per cent, when peeling
medium-sized or large products, eyes and other foul
spots must be removed by hand.
can achieve an hourly capacity of approximately 40 to
60 kgs per person, at a total waste rate of about 30
per cent (if West European continental potatoes are
This is true if the potatoes are to be peeled in an
absolutely accurate way – as it is usual for the
catering industry - .
to high labour costs and normally low potato prices in
this regions (in the European Community), the
industrial peeling factories have been opting for
longer peeling times at higher waste rates.
it is now common in such factories to dispense with
manual "reworking". Potatoes with dark spots
or other damages are sorted out by the personnel at
the roller inspection table and put on conveyor belts
via feeding chutes. These conveyor belts take the
potatoes back to the peeling machine for re-peeling…
the waste rate will be higher, i. e. between 5 and 20
per cent more. But: a good worker at the roller
inspection table will now have an average output
capacity of about 120 to 250 kgs/hr, in case of very
big potatoes still more... Compare the throughput
capacity under item 3.
sorting and re-peeling (at higher waste rates) has,
therefore, proven successful in the EU...
more so since the DORNOW roller peeling machines peel
without water, and the peel pulp produced can be used
for fodder, particularly since it consists at 100 per
cent of potato parts.
method of re-peeling has, however, proved successful
above all in roller peeling machines. Reason: See
items 10 to 13.
batch peelers with bottom and side peeling you will
frequently find "flat" peeling. Due to the
centrifugal forces the potatoes move along the inner
wall and are peeled "flat" this way after
some time. Thus, waste peel is produced in places
where it should not be produced...
DORNOW roller peeling machines this does not occur.
Here, potatoes are peeled largely regularly.
reasons that suggest not to carry out the
after-peeling in carborundum batch peeling machines (with
peeling segments at the bottom and at the sides):
machines with bottom discs >600 mm the potato is
liable to getting inner damages which may result in
colouring and a "second skin".
batch peelers must be coated with a more rough
granulation. A fine graining gets choked too fast so
that the peeling capacity falls off drastically.
elements coated with a rough graining lead to a
product with a rough surface structure which is not
very favourable for the catering industry.
reasons in favour of after-peeling in DORNOW roller
first part of the peeling rollers can be coated with
rough granulation; here, you remove, fast and
thoroughly and without flat peeling, those layers of
the potatoes that have to be removed!
second part of the peeling rollers is coated with a
coarser granulation. Smooth potatoes leave the
re-peeling machine.- The fine granulation doesn't get
choked (see above): the peeling rollers clean
themselves. The consumer will enjoy smoothly and
accurately peeled potatoes thanks to the micro
fine-grain peeling method which can be applied here!
above observations are grounded on many years of
experience. Their publication is non-committal for us.
Please see section
paper contains non-committal notes. We do not lay claim to
completeness. Alterations reserved.
Our order confirmation, accepted by our customers, is in
effect upon delivery. The presentation of a new edition of this treatise will
substitute for any previous versions.
by DORNOW food technology GmbH, D-40549 Düsseldorf
Dornow food technology GmbH,
D-40549 Düsseldorf - Germany, USt-Id.-Nr. DE119264470
Tel. ++49-211-527060, Mobile ++49-172-2614932,
Fax ++49-211-596883, email firstname.lastname@example.org,
AG, Konto-No. 1452333, BLZ 300 400 00, Managing Director Karl-Dietrich
Dornow, Amtsgericht Düsseldorf, HRB 22597