Effect of Different Foliar Particle Films (Kaolin and Zeolitite) on Chemical and Sensory Properties of Olive Oil

Abstract

The use of kaolin foliar treatments in olive growing is a well-established approach that aims at protecting crops from the negative impacts of environmental stresses and from insect pests. The use of zeolite particle films is a far more recent technique. The experimentation was carried out on Correggiolo cv. cultivated in the Emilia-Romagna region (Italy). Foliar treatments were performed in summer until olive harvest. Ripening index, weight, and the oil content of olives were measured. Acidity, peroxide numbers, K232, K270 and total phenols were evaluated as well as fatty acid profiles, determined via GC-FID and phenolic compounds; vitamins and pigments were determined via HPLC-DAD. Quantitative descriptive analysis (QDA) sensory analysis and taint tests were performed. Olives treated with zeolite showed higher oil contents, and the oil obtained exhibited higher contents of total phenols, tyrosol and deacetoxy oleuropein aglycon with respect to the oils produced with kaolin and the control oil. Oils produced from kaolin-treated olives showed sensory profiles characterized by notes of berries (that are not typical of the Correggiolo cultivar). In the scenario of environment-friendly oil production, treatments employing zeolitite particle films represent both a valid alternative to chemical insecticide against olive fly attack and a practice that has a positive influence on the overall oil quality.