FBL x parma impianti rivista

ches, apples, pears and various tropical
fruits. Among these, for some
species of fruit, most tropical a “negative”
sorting is carried out, which
means that not the rejected fruit but
the sound one is removed through
the conveyer belt placed above the
sorting table.
The removal of flabby, necrotic pieces
of fruit by means of knifes, just
a memory of the good old days, also
for tomatoes, is today still in use
only for top quality fruit, mainly tropical
such as mango, for instance.
Personnel in great number removes
besides waste or unwholesome
fruits, also stones and the surrounding
pulp, often worm infested in some
varieties. After this operation,
the wholesome parts recovered are
moved to the chopping station.
It is evident from these notes that
the receiving step virtually leaves
only little room for a fruit-tomato integration.
Only in a few cases and
with keen devices the possibility of
extending it to the washing and sorting
areas can be contemplated.
These integrated operations are
possible if, also topographically, a
choking of the highest capacity line
can be done over parallel planes.
Evidently, any solution in this technical
sector must be developed very
wisely to avoid hindrance and troubles
to the flow of product.
Instead tomato-fruit integration proves
to be easy with low hourly capacity
lines, which means when the
amounts of tomato to be processed
are equal to those of fruit. This is because
the overall availability of raw
material can reach a percentage of
plant utilization large enough to
make it a cost-effective system, all
cost components considered.
Situations like these are found in
many Far-East countries, where
means are rather limited and tomato
doesn’t account for the staple food
item.
Leaving these first stations, tomato
can be processed into different tomato
products.
In the mediterranean areas, pulp, diced
and peeled tomatoes are quite
usual products. Little compatibility
exists between their processing and
that of fruit, even if many varieties of
fruit are commercially available in
the form of diced and peeled fruit
(fruit in syrup and bases for fruit
cocktails).
Instead many areas are overlapping
in case of purees, juices, and, as
seen in previous issues, also for the
production of dehydrated products.
Coming back to our exercise, after
washings, manual inspections and,
alternatively, the optical ones, starts
the important step including chopping
and juice or puree production.
We know what to do for tomato.
The berry is passed through a system
equipped with knifes reducing
it to pulp. Then through a constant
level vat the pulp is transferred to
the heat-exchangers unit where the
tissues are softened and made
ready to be pumped to sievers.
Technology delivering juice to concentrate
is presently well-known by
everybody. We will avoid mentioning
it, while just remembering the possibility,
by applying high temperatures
and a fast flow speed through the
tube-exchanges, to obtain a high viscosity
product with equal total solids
(HB) compared to the standard
(CB). This is linked or not linked to
the destruction of the pectolitic
enzymes present.
This step can be supplemented with
small equipment to make it suitable
also for the production of fruit juices,
either thick or clear (in the latter case
with another specific change in
the plant).
Juice production processes can be
hindered by a stone, occurring in
some varieties of fruit, and, lacking
it, by a high percent content of cellulosic
matter. Stone fruit of mediter-
ranean type can be easily stoned
using simple design stone removing
machines. The fruit, previously washed
and sorted, falls into the hollow
made by two “packs” of spaced rotary
blades with parallel rotation axles.
A device helps pushing cyclically
the fruit into the hollow made by
the blades. This is for fruit intended
for juice and puree preparation. Instead
if fruit is used to make, for instance,
syruped products, where a
still intact fruit is required, processors
must apply another sort of technology
including punches and
special sectioned knifes. They can
stone fruit, dice or slice it. Except for
some cases when peeling (peach) is
performed by a boiling soda solution.
As some pulp pieces can still adhere
to stone, special brushing units
are added to stoners, capable of removing
every still usable edible part.
For the production of tomato juice to
concentrate, the heat-softened pulp,
leaving the tube-nest heaters, is
pumped to the screening unit, where
seeds, peel rags and cellulosic parts
are eliminated. After the sieve
screening, the juice is put into the
storage and feed tank of concentrator.
As to fruit, for the production of juices
intended for the preparation of
cloudy drinks, the high sugar content
and cellulose, occuring in large
quantity, make the process difficult
as often pulpers are inadequate.
Hence the need for special centrifu-
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