Faculté des Sciences

Permanent URI for this community

http://dspace.univ-skikda.dz:4000/handle/123456789/23

Browse

Browsing Faculté des Sciences by Subject "Biochemical Characterization"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Valorization of Biological Activities and Biochemical Characterization of Olive Oils from Selected Cultivars of Olive Tree (Olea europaea L.).
    (University of 20 August 1955, Skikda, 2025) SAHLI, Samir; Nabila, Souilah
    This study aims to characterize the physicochemical, biochemical, and biological properties of olive oils extracted from four Algerian varieties: Akerma, Bouchouk Guergour, Azeradj, and Gordal of Sevilla, according to the fruit ripening stage (green, spotted, and black). The objective is to assess the impact of varietal factors and fruit maturity on quality parameters, lipid composition, and biological activities to optimize the valorization of these oils in the agri-food and therapeutic sectors.The results revealed significant changes in physicochemical parameters with fruit ripening. The maturity index indicates that Bouchouk Guergour reaches an advanced ripening stage faster than Akerma, progressing from 1.8 ± 0.09 at the green stage to 6.2 ± 0.21 at the black stage, while Akerma matures more slowly, from 1.6 ± 0.08 to 6.9 ± 0.17. Regarding oil yield, Akerma reaches a maximum of 12.71 ± 0.17% at the spotted stage, whereas Bouchouk Guergour peaks at 19.56 ± 0.22% at the black stage, highlighting different lipid accumulation strategies between varieties. Azeradj oils showed moderate yields of up to 17.83 ± 0.19% at the black stage, with a balanced fatty acid composition rich in oleic acid (up to 68.54%) and linoleic acid (15.92%), which suggests good nutritional value and oxidative stability. In contrast, Gordal of Sevilla, a variety primarily used for table olives, exhibited the lowest oil yield (5.87 ± 0.11%), but the oils retained acceptable quality parameters and demonstrated interesting biochemical and biological potential despite their low fat content. Oil quality analysis shows that all varieties comply with the International Olive Council (IOC) standards for extra virgin olive oils. Free acidity slightly increases with maturation while remaining within acceptable limits (<0.8%) for all oils analyzed. The peroxide value increases from 3.25 ± 0.2 meq O₂/kg to 9.5 ± 0.3 meq O₂/kg in Akerma and from 9 ± 0.25 meq O₂/kg to 12.5 ± 0.41 meq O₂/kg in Bouchouk Guergour, indicating greater susceptibility to oxidation in more mature olives. The iodine value, an indicator of fatty acid unsaturation, increases with ripening, reaching 90.96 ± 1.71 in Akerma and 85.09 ± 0.9 in Bouchouk Guergour at the black stage, illustrating an enrichment in unsaturated fatty acids. GC-FID and GC-MS analyses revealed distinct fatty acid profiles depending on the variety and ripening stage. Oleic acid (C18:1 n-9) is the predominant fatty acid in all oils, but with significant variations: 73.03% in Bouchouk Guergour compared to 69.30% in Akerma at the green stage. Linoleic acid (C18:2 n-6) increases with maturation, reaching 16.41% in Akerma and 11.62% in Bouchouk Guergour at the black stage, affecting the oxidative stability of the oils. Palmitic acid (C16:0) slightly decreases with maturation in Akerma (from 17.28% to 14.22%) and remains stable in Bouchouk Guergour (9.24% - 9.45%). In vivo biological tests revealed remarkable anti-inflammatory and woundhealing properties in the studied olive oils. The anti-inflammatory activity, measured by the inhibition of xylene-induced ear edema, was highest for oils extracted from black-stage fruits, with inhibition rates of 91.09 ± 0.80% for Akerma and 92.54 ± 0.88% for Bouchouk Guergour after 4 hours, surpassing the effectiveness of Voltaren (79.88 ± 0.50%). Oils from Azeradj and Gordal of Sevilla also showed moderate anti-inflammatory responses, with inhibition percentages exceeding 80% at the black stage. The wound-healing activity, evaluated using a wound model in rats, demonstrated that olive oils enabled complete wound healing within 28 days, with wound contraction rates reaching 100% at the black stage for Akerma and Bouchouk Guergour, and up to 88–95% for Azeradj and Gordal of Sevilla, compared to 26.24% in the Vaseline-treated control group. These results confirm the potential of Algerian olive oils as high-quality products that meet international standards and offer promising agri-food and pharmaceutical applications. To maximize their valorization, future research should focus on optimizing agronomic practices and extraction techniques, conducting in-depth studies on bioactive compounds, and developing functional formulations suitable for the food, cosmetic, and pharmaceutical industries