Review: Near infrared spectroscopy for analysing olive oils

Over the past 30 years, there has been an emphasis on the quality, safety and nutritional proprieties of food products and thus an increasing interest by food producers to reveal frauds and to assure consumers regarding the quality and provenance of their products. In particular, olive oil has become more popular as a healthy food in contrast with the rapid decrease in world demand for animal fats in all their forms. In parallel, near infrared (NIR) spectroscopy has emerged in the food sector as a rapid and very useful tool for such purposes as quality control, process monitoring and estimating shelf-life. Despite its widespread use in the food sector, NIR spectroscopy is not commonly applied online in the olive oil production process: the challenge for the future is the development of dedicated analytical systems and oil analysers that can be used directly and simply in olive mills in order to guarantee the quality and authenticity of olive oil, following its production from the implantation of the tree to the bottling of the oil. This review summarises findings over the Last two decades in which NIR spectroscopy was used for analysing olive oils.