Evaluation of Potential and Real Quality of Virgin Olive Oil from “Campos de Hellín” (Albacete, Spain)

The regulated physicochemical and sensory parameters, stability parameters and fatty acid, sterol and triterpenic dialcohol composition of the olive oils from the varieties Arbequina, Benizal, Cornicabra, Cuquillo, Injerta, Manzanilla de Sevilla, Manzanilla Local, Picual and Negrilla, grown in the Campos de Hellin, were analyzed. Regarding potential quality, all the oil samples were classified in the “extra virgin” category according to the regulated parameters. The oils from the varieties Cornicabra and Picual showed remarkably high stability, due to their high total phenol content. The oils from the Benizal variety stood out due to their high campesterol and low total sterol content, exceeding and not reaching, respectively, the limits set by European regulations. This seems to be an intrinsic characteristic of this variety. When the real quality was analyzed, two clearly differentiated groups were observed: on one hand, oils from the Arbequina variety, and on the other hand, oils from the Picual variety and oils mixed from different varieties (Blend). The great number of olive varieties grown in the Campos de Hellin area enables the production of better balanced oils, producing high quality blended oils since the mixing of different varieties may compensate the deficiencies of monovarietal oils.     

Chemical Composition and Sensory Quality of Tunisian ‘Sayali’ Virgin Olive Oils as Affected by Fruit Ripening: Toward an Appropriate Harvesting Time

Herein, the influence of the ripeness of Tunisian Sayali olives on the chemical composition and sensory quality of virgin olive oils have been investigated, with a particular focus on minor metabolites. Towards this end, five samples (S1–S5) were produced from fruits at increasing stages of maturity and then analyzed. Quality indices (free acidity, peroxide value, specific extinction in UV, sensory characteristics) and composition in major (fatty acids) and minor compounds (squalene, pigments, tocopherols, phenolic compounds, volatile compounds), as well as oxidative stability, were evaluated. Significant variations for the most analytical parameters of Sayali samples were demonstrated, highlighting the impact of stage of ripening. In particular, at later stages of ripening a decreased tendency was seen in minor compounds that are able to inhibit lipid oxidation (tocopherols, carotenoids, squalene and polar phenolic compounds) and, as a consequence, in the oxidative stability value. Moreover, a higher intensity of positive sensory notes (fruity, bitter and pungent) characteristic of extra virgin olive oil were found for samples produced with less ripe olives. Finally, a deeper knowledge of the influence of this factor would be helpful to correctly manage the optimal fruit harvesting time for producers for this variety and to improve the marketing of extra virgin olive oils by using a promising secondary variety (with a high oxidative stability and an interesting fatty acid composition).     

Virgin sunflower oil

Sunflower oil is the second most important virgin oil in Europe but, from the nutritional point of view, the assessment of this oil has become increasingly poorer over the last few years because of the high amount of linoleic acid in traditional sunflower seeds. Today sunflower oil with a high oleic acid content is coming more into the focus of interest since the fatty acid composition is more comparable to rapeseed and olive oil. Another important aspect is that the high content of oleic acid results in a high oxidative stability, making this oil interesting for a wide range of applications. A special challenge is the production of high‐quality tasty virgin sunflower oil because, in contrast to other raw materials, about 30% of sunflower seeds consist of hulls that are covered by waxes. During oil processing these waxes are co‐extracted with the oil, resulting in undesired turbidity of the oil on storage. Pressing of the raw material is done in a screw press or expeller and results in residue fat contents between 7 and 15% depending on the pressing conditions. We discuss two possibilities to avoid or to remove waxes by dehulling of the seeds or winterisation of the resulting oil. Dehulling is carried out by an impact dehuller with removal of the hulls by airflow and gravity. Removal of hulls before pressing improves the sensory quality of the oil because it results in products with a mild sunflower seed‐like nutty taste, while oils from whole seeds often have a woody and bitter taste. In addition, the development of heat during pressing is reduced if dehulled seeds are used for oil production. Conventional sunflower seeds are processed mainly in big oil mills, whereas in small and medium‐sized facilities organic raw material is in use.