Effect of olive leaf phytochemicals on the anti-acetylcholinesterase, anti-cyclooxygenase-2 and ferric reducing antioxidant capacity.

In this study, the phytochemical profile of fifty olive leaves (OL) extracts from Spain, Italy, Greece, Portugal, and Morocco was characterized and their anti-cholinergic, anti-inflammatory, and antioxidant activities were evaluated. Luteolin-7-O-glucoside, isoharmnentin, and apigenin were involved in the acetylcholinesterase (AChE) inhibitory activity, while oleuropein and hydroxytyrosol showed noteworthy potential. Secoiridoids contributed to the cyclooxygenase-2 inhibitory activity and antioxidant capacity. Compounds such as oleuropein, ligstroside and luteolin-7-O-glucoside, may exert an important role in the ferric reducing antioxidant capacity. It should be also highlighted the role of hydroxytyrosol, hydroxycoumarins, and verbascoside concerning the antioxidant activity. This research provides valuable insights and confirms that specific compounds within OL extracts contribute to distinct anti-cholinergic, anti-inflammatory, and anti-oxidative effects.

Changes of the wax contents in mixtures of olive oils as determined by gas chromatography with a flame ionization detector.

Mixing of refined olive-pomace oil with virgin olive oil is a fraud that has been tried often. Normally, the tests that detected the fraud were determinations of wax esters, erythrodiol+uvaol, and stigmastadienes contents. The most common is the determination of wax esters content (extra virgin olive oil is very poor in wax esters, usually less than 100 mg/kg). In this work, the variations of individual wax esters (C40, C42, C44, and C46), with different degrees of unsaturation content, and total wax esters were studied when extra virgin olive oil and refined pomace-olive oil were mixed. The following mixtures were prepared: extra virgin olive oil plus 1, 2, 4, 6, 8, 10, 12, 15, 18, 25, 35, 45, 50, and 80% of refined olive-pomace oil. In all cases, individual and total wax ester content variation was linear with increasing percentage of refined olive-pomace oil in the mixture. The variation of the total wax esters content can be adjusted according to the equation: Total wax esters, mg/kg = 14.3 x (% refined olive-pomace oil) + 83.9.

Influence of harvest date and crop yield on the fatty acid composition of virgin olive oils from cv. Picual.

In this study was analyzed the effect of crop year and harvesting time on the fatty acid composition of cv. Picual virgin olive oil. The study was carried out during the fruit ripening period for three crop seasons. The mean fatty acid composition of Picual oils was determined. The oils contained palmitic acid (11.9%), oleic acid (79.3%), and linoleic acid (2.95%). The content of palmitic acid and saturated fatty acids decreased during fruit ripening while oleic and linoleic acids increased. The amount of stearic and linolenic acids decreased. The amount of saturated acids, palmitic and stearic, and the polyunsaturated acids linoleic and linolenic was dependent on the time of harvest, whereas the amount of oleic acid varied with the crop year. The differences observed between crop years for both palmitic and linoleic acid may be explained by the differences in the temperature during oil biosynthesis and by the amount of summer rainfall for oleic acid content. A significant relationship was observed between the MUFA/PUFA ratio and the oxidative stability measured by the Rancimat method.