Malaxing temperature affects volatile and phenol composition as well as other analytical features of virgin olive oil

Abstract

Malaxing temperature affects volatile and phenol composition as well as other analytical features of virgin olive oilThree Italian olive varieties (Caroleo, Leccino and Dritta) were processed by centrifugation in the oil mill. The olive paste was kneaded at 20, 25, 30 and 35°C. The results achieved revealed that the oil content in green volatiles from lipoxygenase pathway (including C 5 and C 6 compounds and especially unsaturated C 6 aldehydes) decreased progressively as the kneading temperature increased, dropping markedly at 35°C. The content of phenols, o-diphenols and secoiridoids showed an opposite trend, but the temperature of 35°C was critical also for them, as it was for the majority of the other components, analytical parameters and indices related to quality, typicality and genuineness. In general, an increasing kneading temperatures increased the release of oil constituents from the vegetable tissue. This factor also affected the oil extraction yields. The best overall results were achieved by malaxing the olive paste at 30°C. In fact, this temperature level led to achieving both pleasant green virgin olive oils and satisfactory oil extraction outputs.

Phenolic profile of virgin olive oil from advanced breeding selections

“…Moreover, water availability, cultivation zone and sanitary status of the olive fruits (mainly infestation by Bactrocera olea) have a large effect on the phenolic profile of VOO (Morelló et al, 2005;Gómez-Rico et al, 2007;Servili et al, 2007;Gómez-Caravaca et al, 2008;Ripa et al, 2008;Tura et al, 2008). On the other hand, the extraction process, mainly crushing and malaxation steps, highly affects the phenolic composition of VOO due to the activity of endogenous enzymes of olive fruits, which are released in the paste during these steps (Servili et al, 1998;Bianco et al, 2001;Ranalli et al, 2001;Gómez-Rico et al, 2009).…”

Comprehensive two-dimensional gas chromatography for fingerprint pattern recognition in olive oils produced by two different techniques in Portuguese olive varieties Galega Vulgar, Cobrançosa e Carrasquenha

“…Several studies have been carried out comparing aroma compounds, oxidative stability, phenolic compounds, odour and other chemical parameters [9][10][11][12]. The novel analytical scale headspace technique of solid phase micro-extraction (SPME) [13] has become a popular, simple, solvent free method for headspace analysis, allowing quantification in both equilibrium and non-equilibrium situations [14,15].…”

Physico-Chemical Properties, Fatty Acids Content, Oxidative Stability and Antioxidant Activity of some Virgin Olive Oil Cultivars

“…Generally, there are two most important parameters related to fatty acid composition of any oil, one is the ratio of total saturated fatty acids/ total unsaturated fatty acids, which related to the oxidation stability of the oil, while the second is oleic/linoleic ratio, which has a positive effect on the taste of the oil (Ranalli et al, 2001). From the above data (Table 3), it could be noticed that oleic/linoleic ratio was higher in Kronaki olive oil (5.610) followed by Pecual, Frantoio and Chemlali, which recorded 3.560, 2.818 and 2.530; respectively.…”