Abstract Nowadays the avocado fruit (Persea americana Mill.) is widely regarded as an important fruit for its nutritional values, as it is rich in vital human nutrients. The avocado fruit is mainly sold fresh on the market, which however trades also a relevant quantity of second-grade fruits with a relatively high oil content. Traditionally, this oil is extract- ed from dried fruits by means of organic solvents, but a mechanical method is also used in general in locations where drying systems and/or solvent extraction units cannot be installed. These traditional processes yield a grade of oil that needs subsequent refining and is mainly used in the cosmetic industry. In the late 1990s, in New Zeland, a processing company with the collaboration of Alfa Laval began pro- ducing cold-pressed avocado oil (CPAO) to be sold as edible oil for sal- ads and cooking. Over the last fifteen years, CPAO production has increased in many other countries and has led to an expansion of the market which is set to continue, given the growing interest in high- quality and healthy food. Avocado oil like olive oil is extracted from the fruit pulp and in particular shares many principles of the extraction process with extra-vergin olive oil. We conducted a review of tradition- al and modern extraction methods with particular focus on extraction processes and technology for CPAO production. Introduction The avocado fruit originated in Southern Mexico where archaeolog- ical remains and other evidence indicate that its cultivation started in very ancient times, possibly some 6000 years ago. Avocados were grown at the time of the Conquest and spread from Northern Mexico southwards across Central America into North-Western Latin America, extending southwards in the Andean region down to Peru and east- wards into the Andean region of Venezuela (Popenoe, 1935). The com- mercial exploitation of avocado began in the early 1900’s by Californians. Its production in the tropical areas of the world has grown steadily over the last decade and currently accounts for about three million and eight hundred thousand tons of fresh fruit. Most of the produce is grown for fresh consumption, which is also on the increase (FAO, 2014). The avocado fruit (Persea americana Mill.) is widely regarded today as an important fruit for its nutritional values, as it is rich in vital nutrients for the human body. There has recently been an increasing demand in antioxidants, given their beneficial effects on human health. In this respect, avocados contain three of the most important ones, which are vitamins. Avocado fat consists predominantly of mono- unsaturated oleic acid, which has been found to reduce harmful low- density lipoprotein cholesterol, while maintaining beneficial high- density lipoprotein cholesterol, and to perform better than typical low- fat diets (Bergh, 1992; Fulgoni et al., 2013). Although avocado is pri- marily consumed fresh, a substantial increase in the use of avocado- based products (e.g., guacamole) and oil for cosmetics and culinary purposes also suggest further market growth (Bost et al., 2013). Avocado fruit and oil extraction The avocado plants include three different horticultural varieties named after their presumed areas of origin: Guatemala, Mexico and West Indies. Each variety is marked by many different traits, some of which are of commercial relevance (Bergh and Ellstrand, 1986). Today, from the agronomical point of view, there are many varieties with a wide range of sizes, forms and compositions of the fruit. For instance, For instance, Table 1 reports the characteristics of different fruits from varieties harvested in Venezuela (Gómez López, 2002) and clearly shows an example of their variability in particular in terms of size, oil content and seed/pulp proportions. In general, the fruit is roughly pear- shaped and more or less elongated. Its weight may range from 60 g to 700 g. The relative amount of pulp varies from 60 to 75% according to the cultivar. The oil content may also vary widely. The kernel contains only about 1% of oil, whereas the skin accounts for less than 4% (Jacobsberg, 1988). Figure 1 shows the average composition of a Hass avocado from New Zealand. Requejo-Tapia (1999) in New Zealand described the Hass variety as being the most compatible with high- quality oil extraction due to its large amount of flesh with a high oil Correspondence: Giacomo Costagli, Alfa Laval SpA - Market Unit Food, Beverage & Olive Oil, via Sangallo 33, 50028 Tavarnelle Val di Pesa (FI), Italy. Tel.: +39.03927041390. E-mail: giacomo.costagli@alfalaval.com Key words: Avocado; oil; cold-pressed; centrifuge; extra virgin; Alfa Laval. Contributions: the authors contributed equally. Conflict of interest: GC and MB, who contributed part of the materials used in this study, are employees of Alfa Laval SpA (Tavarnelle Val di Pesa, Florence, Italy). Received for publication: 21 April 2015. Accepted for publication: 20 August 2015. ©Copyright G. Costagli and M. Betti, 2015 Licensee PAGEPress, Italy Journal of Agricultural Engineering 2015; XLVI:467 doi:10.4081/jae.2015.467 This article is distributed under the terms of the Creative Commons Attribution Noncommercial License (by-nc 3.0) which permits any noncom- mercial use, distribution, and reproduction in any medium, provided the orig- inal author(s) and source are credited. Avocado oil extraction processes: method for cold-pressed high-quality edible oil production versus traditional production Giacomo Costagli, Matteo Betti Alfa Laval SpA - Market Unit Food, Beverage & Olive Oil, Tavarnelle Val di Pesa (FI), Italy [Journal of Agricultural Engineering 2015; XLVI:467] [page 115] Journal of Agricultural Engineering 2015; volume XLVI:467 Non commercial use only