اندازه گیری مقادیر پلیفنل میوه زیتون و ارزیابی قدرت آنتی اکسیدانی در چند رقم ناشناخته ایرانی

Olive and Olive oil represents the typical lipidic source of the Mediterranean diet, a dietary habit which has been associated with a low incidence of several pathologies, including cardiovascular diseases and neurological disorders and Cancers. Polyphenols are bioactive molecules, present in all plant species, acting as free radical scavengers, they are chiefly responsible for the intrinsic defense against the autoxidation of unsaturated fatty acids, increasing the shelf life of the oil. It is amply reported that polyphenol concentration of extra virgin olive oils may differ, depending on both cultivars and environmental factors, as well as the degree of ripeness of the olives.
In this study, the methanolic extract of extra virgin olive oil was obtained, and then total phenolic content was determined colorimetrically using the Folin-Ciocalteau. Absorbance was measured at 765 nm. For each sample, three replicate assays were performed. The total phenolic content was calculated as gallic acid equivalent. Determination of the free radical scavenging activity of the different extracts was carried out using a modified quantitative DPPH assay. Absorbance was measured at 517 nm. The concentration of the total phenolic fractions extracted from different olive samples indicates a high variability in the phenolic content of the extra virgin olive available on the farme. Positive correlations between antioxidant capacity and total phenolic content suggest that the antioxidant activities of the olive extract can be mainly ascribed to their phenol compounds.