Effect of macronutrient fertilization on olive oil composition and quality under irrigated, intensive cultivation management

Abstract

BACKGROUND Intensive olive (Olea europaea L.) orchards are fertilized, mostly with the macronutrients nitrogen (N), phosphorus (P) and potassium (K). The effects of different application levels of these nutrients on olive oil composition and quality were studied over 6 years in a commercial intensively cultivated ‘Barnea’ olive orchard in Israel. RESULTS Oil quality and composition were affected by N, but not P or K availability. Elevated N levels increased free fatty acid content and reduced polyphenol level in the oil. Peroxide value was not affected by N, P or K levels. The relative concentrations of palmitoleic, linoleic and linolenic fatty acids increased with increasing levels of N application, whereas that of oleic acid, monounsaturated‐to‐polyunsaturated fatty acid ratio and oleic‐to‐linoleic ratio decreased. CONCLUSION These results indicate that intensive olive orchard fertilization should be carried out carefully, especially where N application is concerned, to avoid a decrease in oil quality due to over‐fertilization. Informed application of macronutrients requires leaf and fruit analyses to establish good agricultural practices, especially in view of the expansion of olive cultivation to new agricultural regions and soils. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Integrated Use of Organic and Bio-fertilizers to Improve Yield and Fruit Quality of Olives Grown in Low Fertility Sandy Soil in an Arid Environment

“…on the other hand, oleic acid, the monounsaturated-to-polyunsaturated fatty acid ratio, and the oleic-to-linoleic ratio decreased. N, P, or K levels had no impact on the peroxide value [13]. Calcium spraying treatment during the growing season increased the oil content and the concentration of phenol compounds in fruits of Manzanilla de Sevilla and Ascolanta tenera olive cultivars [14,15].…”

Extra Virgin Olive Oil Composition and its Bioactive Phenolic Compounds

“…A daily dose of 2-15mg of hydroxytyrosol or oleuropein related compounds is required for the scientific validation of health claims. PUFA are protected from oxidation by these polyphenols and tocopherols that have a positive impact on consumer health [2,7,15]. Positive correlations were found…”

“…Oleic acid is one of the main characteristics of olive oil that is associated with health. Phenolic compounds, oleic acid, polyunsaturated fatty acids, phytosterols, squalene, tocopherols are effective on consumer health [7]. Oleic acid (55-85%) is the most abundant monounsaturated fatty acid in olive oil, followed by saturated palmitic acid (7.5-20%), polyunsaturated linoleic (3.5-21%), and linolenic (1%) acids [2,8].…”