Olive Growing Systems, Varieties and Olive Oil Production Systems

Portuguese olive groves suffered a great setback in the decades of 1950s–1960s of the twentieth century with the rural exodus. Portugal’s entry into the EEC/EU in 1986 created conditions to the reconversion of existing olive groves, enabling the plantation of new orchards with 200–300 trees per hectare and the use of varieties from other regions. At the beginning of the twenty-first century, the construction of the Alqueva Dam in the Alentejo region led to an increase in the area of irrigated olives groves. The hedge olive grove concept with continuous mechanized harvesting and the availability of water for irrigation contributed to the increase of this new growing system, reaching about 50,000 ha in two decades. Furthermore, olive oil production systems are also the focus of this section. Indeed, olive oil production encompasses, previously, the collection of olives and their washing followed by an extraction process. This step, comprising crushing/malaxing with or without water and finally centrifuging/decanting processes, is typically feasible using two types of systems: a traditional discontinuous press process and a continuous three-phase centrifugal or two-phase centrifugal extraction systems. Thus, a descriptive summary of the different olive oil extraction systems will be presented covering their advantages and drawbacks. Also, recent approaches and innovations introduced in the olive oil extraction chains, in order to improve the working efficiency of the production system and to obtain high-quality extra virgin olive oils (EVOOs), will be highlighted. In Portugal, a change in the sector of olive oil has undergone reflecting in the modernization of the mills to increase production capacity, offsetting the increase in production and increasing consumption.