Cultivar determines fatty acids and phenolics dynamics for olive fruit and oil in super-high-density orchards

Abstract

The dynamics of maturation index, water and oil concentrations, and total phenols in olive fruit, together with fatty acids and total phenols content in olive oil, was studied as a function of time after flowering for super-high-density ‘Arbequina’, ‘Arbosana’ and ‘Koroneiki’ using data collected in three seasons. Oil concentration increased linearly from the middle of August until reaching a plateau by the end of November for all three cultivars, with ‘Koroneiki’ (45.7 g/100 g) and ‘Arbosana’ (45.4 g/100 g) showing higher maximum oil concentration than ‘Arbequina’ (41.8 g/100 g). While total phenols in the fruit decreased linearly during the harvest for all three cultivars, phenolics in oil peaked at 180 days after flowering (400 mg/kg) for ‘Arbequina’ and at 160 days after flowering (600 mg/kg) for ‘Koroneiki’. For ‘Arbosana’, total phenols in oil decreased linearly with a maximum of 400 mg/kg for early harvest oils. Fatty acid dynamics was largely affected by genotype, with ‘Arbequina’ displaying the largest variation in fatty acid concentrations along the season. ‘Koroneiki’ presented the highest values of oleic acid (73.0–77.1%), followed by ‘Arbosana’ (70.2–72.4%) and ‘Arbequina’ (64.4–74.0%). Results presented here are useful for growers to make planting and harvesting decisions, for producers to understand the differences in oil made from the most common super-high-density cultivars during the harvest seasons, and for regulators to consider legal standards for authentic olive oil.