GrasasYaceites 1-57. pdf

10. STORAGE
The olive oil is extracted for 2-3 months but is
consumed during the year and therefore it should
be stored until packing. This is the last step in the
quality chain, and the oil manufacturer is mainly
responsible. The objectives are:
• Quality separation
• Saving the oil characteristics protecting it from
oxidation and aroma losses and avoiding
acquisition of negative attributes.
• Helping the oil maturation, this process
reduces the astringency, bitterness.
For quality separation, the oils extracted during
the day should be preliminarily catalogued
according to their acidity and sensory
characteristics, and stored in different tanks. For
this, different storage tanks are needed (capacity
lower than 50 T) or tanks with a capacity lower than
the oil production for 3 days.
Fermentation should be avoided through a
periodical tank bleeding since on the bottom there
are impurities where fermentation can appear;
because of that the bottom of tanks should be
conical. To protect against oxidation and aroma
losses, the oil temperature should be moderate and
oil aeration, light exposure and metal trace
contamination should be avoided since they act as
oxidation catalysts. The storage conditions should
be:
• Bodega with constant temperature (15-18ºC)
which assists in oil maturation.
• Avoid oil movements between storage tanks.
• Covered tanks
• Tanks made with stainless steel.
• The bodega should be clean, ventilated and
without any smell (fume, gas-oil) since oil
might take on undesirable smells.
11. PROCESS AUTOMATION
The two way system helped to solve the
alpechín contamination problem, but it has less
visual controls in process regulation. Therefore
process automation is needed to obtain a high
quality product, optimal process yields at low costs
(Gonzalez et al., 1997). In the 90s the first software
was applied to control and monitor the extraction
process regulating some important process
variables, automatically and by operator order, to
obtain efficient yields and high quality oils.
These systems are formed by software with a
user interface that receives process data from
specific sensors. Evaluating the data acquired and
the order established the software changes the
process parameters acting on the regulation
mechanism, electro valves, automatic valves,
variable speed devices, etc until the parameters are
adjusted to established orders.
From 1992 in CIFA ‘Venta del Llano’ several
automation and control systems have been
evaluated (González et al., 1993). In general,
instrument reliability was acceptable as observed in
Figure 5 for differences between olive weight and
the paste amount loaded in the decanter.
For regulation of olive paste temperature
automatic differences were not found between
automatic and manual measurement (Figure 6).
Paste feed loaded in the decanter is very important
for process regulation and showed higher reliability
when automatic control is performed (Figure 7).
Using automation system in CIFA ‘Venta del Llano’
have been obtained better process yields (Figure
8). At present, new sensors based on NIR and
microwave technologies are being developed. They
will help to know the process performance and its
regulation.
30
GRASAS Y ACEITES
, 57 (1), 
ENERO
-
MARZO
, 25-31, 2006, 
ISSN
: 0017-3495
MARINO UCEDA, ANTONIO JIMÉNEZ AND GABRIEL BELTRÁN

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