Virgin Olive Oil Phenols, Fatty Acid Composition and Sensory Profile: Can Cultivar Overpower Environmental and Ripening Effect?

Abstract

The authenticity and typicity of monocultivar oils and knowledge of the changes that environmental olive growing conditions bring to naturally present antioxidants and sensory attributes of virgin olive oils (VOO) are important for quality and safety improvement. This study delivers a comprehensive evaluation of the factors affecting phenolics, fatty acid composition and sensory characteristics of cultivars Oblica and Leccino VOOs throughout ripening season at two distinct olive growing environments during three consecutive crop years, and ranks the importance of each factor. Specified parameters were significantly influenced by olive growing environmental conditions. At the colder location of higher altitude, both cultivars gained higher amount of stearic, linoleic and linolenic fatty acids, as well as a higher proportion of phenolic compounds, but lower amounts of oleic fatty acid. At the warmer location of lower altitude, both cultivars had oils with lower level of fruitiness, bitterness and pungency. Analysis of the main components showed that VOOs were primarily differentiated by the cultivar, then main groups were divided with regard to the growing site, while harvest period affected the biosynthesis of natural VOOs antioxidants but had the least impact. These results reveal that the composition of fatty acids, phenolic content and sensory profile are predominantly characteristics of a cultivar.

Keywords: C18:1/C18:2; Olea europaea L.; fatty acids; growing conditions; maturity index; phenols; sensory quality.

Figure 1

Microclimatic parameters measured for each olive growing site; (A) Kaštela and (B) Šestanovac.

Figure 2

Total phenol concentration (mg/kg) of Oblica (A) and Leccino (B) virgin olive oils during ripening, obtained from two distinct olive orchards (Kaštela and Šestanovac) in three successive crop years. Bars labelled by different lowercase letters, for each crop year, are significantly different, while different uppercase letters indicate differences within main effects (crop year, growing site and harvest period), obtained by three-way ANOVA (Tukey’s test, p ≤ 0.05). 1–4, harvest period, see also Table 1.

Figure 3

Sensory profile of Oblica virgin olive oils obtained in 3 successive crop years from the 2 distinct olive orchards at 4 harvest periods. (A)—Kaštela 2010, (B)—Kaštela 2011, (C)—Kaštela 2012; (D)—Šetanovac 2010, (E)—Šetanovac, 2011, (F)—Šetanovac 2012; 4 harvest periods—line colors 1–4 within each graph.

Figure 4

Sensory profile of Leccino virgin olive oils obtained in 3 successive crop years from the 2 distinct olive orchards at 4 harvest periods. (A)—Kaštela 2010, (B)—Kaštela 2011, (C)—Kaštela 2012; (D)—Šetanovac 2010, (E)—Šetanovac, 2011, (F)—Šetanovac 2012; 4 harvest periods—line colors 1–4 within each graph.

Figure 5

(A) Projection of the variables (basic quality parameters (FFA, PV, K numbers), fatty acid composition, tocopherol composition, total phenols (TPC) and sensory properties) of the first two factors, obtained by principal component analyses; and (B) projection of the virgin olive oil samples of Oblica (O) and Leccino (L) grown in Kaštela (K) and Šestanovac (S) during ripening (1–4, harvest period, also see Table 1) in 3 successive crop years (1–3, number after the point) in the two-dimensional space of first 2 factors.