Genetic and environmental features for oil composition in olive varieties

Abstract

Consumption of olive oil helps both prevent and cure heart disease. Olive oils vary in their fatty acid profiles as well as those of other secondary metabolites (phenols, sterols, and terpene compounds). We seek to distinguish the genetic bases from the environmental factors that cause these variations. The genetic base is indeed wide: varieties originate in different domestication occurrences, from different oleaster trees and in differing climatic regimes. With the aid of diagrams, we set out briefly the oil synthesis pathway for fruits in comparison with that of seeds, and the specific aspects of olive oil in particular. Varieties of olive have appeared that are adapted to regions with harsh conditions where the oleaster could not thrive. Environmental stresses have consequences on drupes and their oil profiles; these have been highlighted in European countries through the use of appellations. Whilst stresses tend to enhance the quality of the end product, they do however decrease final yields with potential negative impacts on olive growers’ incomes. Irrigation experiments are underway in order to determine the optimal amount of watering. In breeding new varieties, the result sought is that of accumulating pest tolerances and fruit-quality characteristics; selection programmes are however expensive as they necessitate observations over many years. Consumers have choice across a range of appellations with different organoleptic specificities at different prices, and whatever the appellation of the oil they can expect a positive effect on their health.