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Comprehending the variability in the chemical composition of olive oil from the same olive variety, based on its geographical origin, is essential. This study investigated the chemical composition of Chétoui olive oils from thirteen mills located in Northern Tunisia's Béja region. The chemical composition of olive oil exhibits substantial regional variability. Free acidity ranged from 0.57% to 0.73%, and peroxide values varied between 7.33 and 14.00 meq O2/kg. Total phenolic content varied as well, with values ranging from 906.53 to 1,298.60 caffeic acid eq/kg (oils from Amdoun and Testour II, respectively). Chlorophyll contents ranged from 2.03 to 7.85 mg/kg, and carotenoids from 1.28 to 3.92 mg/kg. Olive oils from Amdoun and Dogga II were the richest in these compounds. In terms of tocopherols, the range extended from 282.88 mg/kg (oil from Tibar) to 416.79 mg/kg (oil from Testour II). DPPH radical scavenging activity of the polar fraction of all olive oils was higher than that of the non-polar fraction. Fatty acid profiles were mostly similar with exception of the oil from Tibar with lower saturated fatty acid content and higher monounsaturated fatty acid content. Substantial differences in polyunsaturated fatty acid content were found. Triacylglycerol compositions differed as well, with the lowest triolein percentage around 13.66% and the highest at approximately 34.98%. In summary, this study reveals significant regional variations in the chemical composition of Chétoui monovarietal olive oil, highlighting the collection region impact on oil quality and nutritional properties. [ABSTRACT FROM AUTHOR]

In this study, we investigated the role of seed priming in mitigating depressive effects of high salinity on membrane lipid composition and membrane functionality in seedlings of Hasawi rice cultivar (Oryza sativa L). Results indicated that seed pre-treatment with hydropriming (HP) and priming with 50 mM NaCl solution enhanced germination performance and early seedling growth under salinity condition. Priming treatments were found effective in maintaining membrane stability and integrity by increasing total membrane lipid content and reducing membrane damage. Concentrations of monogalactosyldiacylglycerol, digalactosyldiacylglycerol and phosphatidylglycerol were greatly increased when seeds were primed. Priming also increased phosphatidylcholine PC (lipid forming lamellar structure) and maintained phosphatidylethanolamine PE (non-bilayer-forming lipid) levels resulting in enhanced PC/PE ratio under salinity condition. Membrane unsaturation level was also increased, suggesting an improvement in membrane fuidity under salinity conditions. HP and NaCl-priming with 50 mM also induced increased contents of total phenolics, total soluble sugar and proline as compared to unprimed seedlings subjected to salinity. It is concluded that HP and priming with 50 mM NaCl solution can offer perspectives to improve germination and early growth of Hasawi rice under high salinity. This could be achieved through down-regulation of oxidative stress, accumulation of osmoprotectant compounds and improving cell membrane fuidity and integrity. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the influence of the solvent type on the extraction of phenolics and the antioxidant properties of the extracts obtained from Chétoui olive leaves. Extraction was conducted at room temperature using four solvents: deionized water (ddH2O), 80% methanol (80% MeOH), 70% ethanol (70% EtOH), and 80% acetone. Total phenols and total flavonoids were measured using the Folin-Ciocalteau and aluminum chloride colorimetric methods, respectively. The antioxidant properties have been determined by two scavenging activity methods, DPPH and ABTS. The total phenol and flavonoid contents of the olive leaf extracts (OLEs) ranged from 16.52 to 24.93 mg gallic acid g-1 DM and from 6.23 to 21.47 mg catechin g-1 DM, respectively. The IC50 values of DPPH varied from 0.17 to 0.97 mg mL-1 and the antioxidant activity values determined by ABTS (trolox equivalent antioxidant capacity) were between 629.87 and 1064.25 µmol TE g-1 DM. Our results revealed that extracting solvents have a significant influence on the antioxidant properties of olive leaves and that a methanol mixture is recommended for extracts with high levels of flavonoids and important antioxidant activities. Moreover, it was noticed that the trolox equivalent antioxidant capacity (TEAC) depends more on the flavonoids (r = 0.821) than on the total phenols (r = 0.399). [ABSTRACT FROM AUTHOR]