Chapter 11 - Olive-oil quality biotechnologies

Abstract

This chapter presents information on the basic composition of olive oil, oil standards, the quality and purity of olive oil and how these are measured, and current research on olive oil quality analysis, with an emphasis on oil cultivated in desert conditions. Olive oil is the lipophilic product of olive fruit. Olive oil is mostly composed of triglycerides or triacylglycerols (TAGs) and some small quantities of free fatty acids (FFA), glycerol, phosphatides, pigments, flavor compounds, sterols, unidentified resinous substances and other constituents. The International Olive Council (IOC) is an intergovernmental organization based in Madrid, Spain, with 23 member states that subscribe to a United Nations charter to develop standards for quality and purity criteria for olive oil. The main aim of the IOC is to promote olive oil around the world by tracking production, defining quality standards, and monitoring authenticity. More than 85 percent of the world's olives are grown in IOC member nations. Olive oils have been classified into different grades, such as industrial and retail. According to this, olive oil can be classified as virgin oil, refined oil and pomace oil. The IOC and the EEC have defined the quality of olive oil; based on parameters that include free fatty acid (FFA) content, peroxide value (PV), UV absorbency, and sensory score. In particular, the quantity of FFA is an important factor for classifying olive oil into commercial grades. Intensive studies have been carried out in recent years, mainly in Israel, regarding the quality of desert-grown olive oils. Factors that affect the quality of olive oil can be grouped into those that act during oil formation in the fruit, during fruit collection, and during the processing and storage of oil. Genetic (varietal), climatic, and environmental factors might affect all these stages.