Virgin Olive Oil Enriched with Lutein-Zeaxanthin from Spinacia oleracea.

The aim of this work consists of developing a technological process for elaborating a virgin olive oil enriched in lutein-zeaxanthin extracted from spinach, studying different parameters like temperature, time of extraction and different ratios (spinach-oil). It was observed that the amount of carotenoids extracted increased up to a maximum after 24 hours and decreased as the maceration time progressed up to 60 hours, resulting of biological degradation. It was also observed that as more spinach we added, as more lutein-zeaxanthin in the enriched virgin olive oil was obtained. The best results were obtained after 24 hours by using a 75:25 ratio at 30°C. Values of oxidative stability decreased drastically, as well as other parameters such as acidity; peroxides index and Ks were modified when the enriched virgin olive oil was subjected to 45°C for 24 hours of maceration. Thus, the present procedure constitutes a way to achieve an increase in the daily intake of beneficial compounds.

Influence of the fruit's ripeness on virgin olive oil quality.

Virgin Olive Oil (VOO) is a product much demanded by consumers looking for the highest quality and certain traits considered to be typical of the Mediterranean area. The olive fruit's properties and the industry-regulated physicochemical and sensory parameters of seven cultivars were evaluated during the ripening process. In general, the oil percentage in both the wet and dry material increased for all the cultivars from the green to the spotted stages of maturation, and they stayed constant statistically until the ripe stage with just a few exceptions. The lowest oil content was observed in the Manzanilla Cacereña cultivar in all stages of maturation. The cultivars that presented the lowest oil yields in the Abencor system were Manzanilla Cacereña and Carrasqueña, and the highest Corniche. In general, all the cultivars except one presented good behaviour during the mixing process, the exception being Manzanilla Cacereña which presented the lowest values of the extractability percentage. The moisture content of the olives presented a common pattern, increasing from the green to the spotted stage, with the differences being significant in the Corniche, Picual, and Verdial de Badajoz cultivars. All the oils analysed were classified into the "extra virgin" category according to the results for the regulated parameters. The fruity, bitter, and pungent attributes decreased during ripening in all the cultivars studied. In the green stage of maturation, Arbequina had the least intensity of bitterness and pungency, but there were no significant differences among cultivars in the fruity attribute.

Phenolic compounds and antioxidant capacity of virgin olive oil.

The characterisation of virgin olive oil from Arbequina, Carrasqueña, Corniche, Manzanilla Cacereña, Morisca, Picual, and Verdial de Badajoz varieties according to the individual phenolic compounds at different ripening stage was carried out. In all olive oil varieties studied, secoiridoid derivatives were most abundant, followed by phenolic alcohols, flavonoids and phenolic acids. The secoiridoid derivatives of hydroxytyrosol were the most important complex phenols for Picual and Carrasqueña, whereas the tyrosol derivatives were the major ones found in Manzanilla Cacereña, and Verdial de Badajoz. For secoiridoid derivatives of hydroxytyrosol and tyrosol, Arbequina was the oil variety showing the lowest concentration. Tyrosol, hydroxytyrosol, vanillic acid, p-cumaric acid, luteolin, and apigenin levels were greater in early harvested samples in almost all oils analysed. Antioxidant activity measurements (antiradical, lipid peroxide inhibition, H2O2 and NO scavenging) were also accomplished for the seven varieties in the first ripening stage.