GrasasYaceites 1-57. pdf

Olive oil extraction and quality
By Marino Uceda, Antonio Jiménez and Gabriel Beltrán
CIFA ‘Venta del Llano’. Instituto Andaluz de Investigación y Formación Agraria, Pesquera,
Alimentaria y de la Producción Ecológica (IFAPA). CICE, Junta de Andalucía.
P.O. Box 50, 23620 Mengibar, Jaén. Spain.
(Spanish Agriculture, Fisheries and Food Ministry)
to apply for subsidies for recent crop years.
The Spanish olive oil sector has made an
important effort to significantly increase its milling
capacity in order to adapt to the annual needs of
olive growers. In this way, the daily milling capacity
reported at the end of the 80s was 400000 T/day,
achieving more than 237000 T, which is currently
six times higher.
In theory a mean crop year (around 5.5 million T
of olive fruits) can be milled in 2.5 days. Extraction
technology has changed considerably from the
press extraction system (70s and 80s) to the
continuous systems by centrifugation called ‘Three
phases’. However the contaminant capacity of the
liquid by-product (alpechín) (COD 100000 ppm), its
amount produced (1.2 L/kg olives) and the growing
interest in the environmental quality promoted a
technological solution for this problem, the
development of the ‘two way’ system (in the 90s)
that reduces the liquid by-product and its
contaminant capacity.
At present, both systems (two and three way)
are working. The Two way system represents more
than 90% of the milling capacity while the press
systems have practically disappeared.
2. SCHEME OF THE EXTRACTION PROCESS
The olive oil extraction process starts in the olive
fruit, the first step in the oil industry. Because of that,
its harvesting and transport have great importance
since they affect, sometimes significantly, the oil
quality and process yield. However, considering that
olives arrive in optimal conditions to the oil mill, we
can focus on the process steps that are shown in the
following scheme:
– Previous operations
– Fruit reception
– Fruit characterization
– Fruit preparation
– Cleaning
– Washing
25
GRASAS Y ACEITES
, 57 (1),
ENERO
-
MARZO
, 25-31, 2006,
ISSN
: 0017-3495