Influencia de la temperatura de almacenamiento sobre los parámetros de calidad, fenoles y compuestos volátiles de aceites de oliva vírgenes croatas

The influence of low storage temperature (+4 °C and －20 °C) and conventional storage room temperature on the quality parameters, phenolic contents and volatile profiles of Buža, Črna and Rosinjola monovarietal virgin olive oils after 12 months of storage was investigated in this study. Virgin olive oils stored at low temperatures maintained better quality parameters than oils stored at room temperature. A negligible decrease in the total phenols was detected after 12 months of storage at all investigated temperatures. The total volatile compounds, aldehydes, alcohols and esters in almost all stored samples were unchanged compared to fresh oils. Total ketones increased after storage, although at a lower temperature these changes were less notable. An increase in the oxidation indicators hexanal and hexanal/E-2-hexenal ratio was the lowest in oils stored at +4 °C.Storage at temperatures lower than room temperature could help to prolong the shelf-life of extra virgin olive oil by maintaining high quality parameters and preserving the fresh oil’s volatile profile.Se ha estudiado la influencia, durante 12 meses, de temperaturas bajas (+4 °C y −20 °C) y convencional (ambiente), sobre los parámetros de calidad, contenido fenólico y perfil de volátiles de aceites de oliva vírgenes monovarietales Buža, Črna y Rosinjola. Los aceites de oliva vírgenes almacenados a bajas temperaturas mantienen mejores propiedades de calidad que los aceites almacenados a temperatura ambiente. Se encontró una disminución no significativa de los fenoles totales después de 12 meses de almacenamiento a todas las temperaturas estudiadas. Los compuestos volátiles totales, aldehídos, alcoholes y ésteres, en casi todas las muestras almacenadas, se mantuvieron sin cambios en comparación con los aceites frescos. Las cetonas totales incrementaron tras el almacenamiento, aunque a temperaturasmas bajas estos cambios fueron menos notables. El incremento de los indicadores de la oxidación hexanal y la relación hexanal/E-2-hexenal fue más bajo en los aceites almacenados a +4 °C. El almacenamiento a temperaturas inferiores a la temperatura ambiente ayuda a prolongar la vida útil de los aceites de oliva virgen extra, manteniendo la alta calidad y preservando el perfil de volátilesde un aceite fresco

Influence of storage temperature on quality parameters, phenols and volatile compounds of Croatian virgin olive oils

The influence of low storage temperature (+4 °C and －20 °C) and conventional storage room temperature on the quality parameters, phenolic contents and volatile profiles of Buža, Črna and Rosinjola monovarietal virgin olive oils after 12 months of storage was investigated in this study. Virgin olive oils stored at low temperatures maintained better quality parameters than oils stored at room temperature. A negligible decrease in the total phenols was detected after 12 months of storage at all investigated temperatures. The total volatile compounds, aldehydes, alcohols and esters in almost all stored samples were unchanged compared to fresh oils. Total ketones increased after storage, although at a lower temperature these changes were less notable. An increase in the oxidation indicators hexanal and hexanal/<em>E</em>-2-hexenal ratio was the lowest in oils stored at +4 °C.Storage at temperatures lower than room temperature could help to prolong the shelf-life of extra virgin olive oil by maintaining high quality parameters and preserving the fresh oil’s volatile profile.<br><br>Se ha estudiado la influencia, durante 12 meses, de temperaturas bajas (+4 °C y −20 °C) y convencional (ambiente), sobre los parámetros de calidad, contenido fenólico y perfil de volátiles de aceites de oliva vírgenes monovarietales Buža, Črna y Rosinjola. Los aceites de oliva vírgenes almacenados a bajas temperaturas mantienen mejores propiedades de calidad que los aceites almacenados a temperatura ambiente. Se encontró una disminución no significativa de los fenoles totales después de 12 meses de almacenamiento a todas las temperaturas estudiadas. Los compuestos volátiles totales, aldehídos, alcoholes y ésteres, en casi todas las muestras almacenadas, se mantuvieron sin cambios en comparación con los aceites frescos. Las cetonas totales incrementaron tras el almacenamiento, aunque a temperaturasmas bajas estos cambios fueron menos notables. El incremento de los indicadores de la oxidación hexanal y la relación hexanal/<em>E</em>-2-hexenal fue más bajo en los aceites almacenados a +4 °C. El almacenamiento a temperaturas inferiores a la temperatura ambiente ayuda a prolongar la vida útil de los aceites de oliva virgen extra, manteniendo la alta calidad y preservando el perfil de volátilesde un aceite fresco

Towards understanding the varietal typicity of virgin olive oil by correlating sensory and compositional analysis data: a case study

To investigate if the anecdotal varietal typicity concepts for two monovarietal virgin olive oils (VOO) can bescientifically supported and explained, VOO samples were sorted according to typicity grade and related tosensory and compositional data for volatiles and phenols. Clear inter-varietal, as well as intra-varietal bound-aries between more and less typical samples were established by univariate and multivariate statistics. A variety-typical complex odor was related to a complex VOO volatile composition with relatively high amounts of li-poxygenase-derived compounds, accompanied by hydrocarbons, terpenes, and benzenoids. A simpler odor,described mostly as green and typical for the other monovarietal VOO, coincided with the lower amounts of thesame volatiles. The intensity of bitterness and pungency was mostly in correlation with the amount of majorphenols. Two monovarietal VOOs were clearly distinguished with respect to their variety-typical expression ofpungency: the one described as gradually increasing was tentatively related to pinoresinol, while the other, de-scribed as immediately strong and burning, was assumed to originate mainly from p-HPEA-EDA. Intra-varietaltypicity grades correlated with hedonic liking, as well as with general VOO positive sensory attributes related tokey volatiles and phenol

Complementary untargeted and targeted metabolomics for differentiation of extra virgin olive oils of different origin of purchase based on volatile and phenolic composition and sensory quality

In order to differentiate the extra virgin olive oils (EVOO) of different origin of purchase, such as monovarietal Italian EVOO with protected denomination of origin (PDO) and commercial-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of volatile aroma compounds by both targeted gas chromatography/mass spectrometry (GC-MS) and untargeted profiling by comprehensive two-dimensional gas chromatography/mass spectrometry (GC×GC-TOF-MS), analysis of phenols by targeted high-performance liquid chromatography/mass spectrometry (HPLC-DAD-ESI/MS), and quantitative descriptive sensory analysis. Monovarietal PDO EVOOs were characterized by notably higher amounts of positive LOX-derived C6 and C5 volatile compounds, which corresponded to the higher intensities of all the assessed positive fruity and green odor sensory attributes. Commercial-blended EVOOs had larger quantities of generally undesirable esters, alcohols, acids, and aldehydes, which coincided with the occurrence of sensory defects in many samples. Many minor volatile compounds that were identified by GC×GC-TOF-MS were found to differentiate each of the two investigated groups. The differences between the groups with respect to phenols and taste characteristics were evident, but less pronounced. The results that were obtained in this study have undoubtedly confirmed the existence of the large heterogeneity of oils that are sold declared as EVOO. It was shown that GC-MS, GC×GC-TOF-MS, and HPLC-DAD-ESI/MS analyses have complementary outputs, and that their use in combination has advantages in supporting the results of sensory analysis and objectively differentiating these groups of EVOO