en Nutrition Nutrition پژوهشي Research <p style="margin: 0px 0px 13.33px; text-align: justify; line-height: 200%; unicode-bidi: embed; direction: ltr;"><strong>Background and Objectives: </strong>According to recent research, olive leaf (OL) has demonstrated significant properties, including antibacterial, antiviral, anticancer, gastro protective and cardio protective properties. The aim of this study was to investigate the chemical composition, and fatty acid composition (FAC) of OL of <em>Marry</em> variety cultivated in Jiroft province of Iran. This study also attempts to identify and quantify the polyphenolic compounds of OL of <em>Mari.</em><br> <strong>Materials and Methods: </strong>The content of dry matter (DM), crude protein (CP), ash, fat ether extract (FEE), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of OL, FAC, type and amount of polyphenol compounds, antioxidant activity (AA%), total phenol, tannin, flavonoid contents (TPC, TTC, and TFC, respectively), were determined, all procedures were performed according to the reference methods.<br> <strong>Results: </strong>The content of DM, and CP, Ash, FEE, ADF, and NDF of OL obtained 94.7<span dir="RTL">&plusmn;</span>0.08 (%), and 13.08<span dir="RTL">&plusmn;</span>0.06, 6<span dir="RTL">&plusmn;</span>0.7, 3.9<span dir="RTL">&plusmn;</span>0.28, 32.48<span dir="RTL">&plusmn;</span>0.56, 40.6<span dir="RTL">&plusmn;</span>0.26 (DM%), respectively. The amounts of TPC, TTC and TFC of OL were obtained 108.24<span dir="RTL">&plusmn;</span>0.09, 56.85<span dir="RTL">&plusmn;</span>0.10 (mg Gallic acid (GAE)/g dried OL) and 189.28<span dir="RTL">&plusmn;</span>.012 (mg Quercetin (QE)/g dried OL), respectively. Results showed that oleuropein was the dominant polyphenol (8306<span dir="RTL">.</span>9&micro;g/ g of dried OL). The AA% of OL extract was obtained 61%&plusmn;0.9%. The FAC of OL was determined by gas chromatography (GC) and the results showed linoleic acid (27.2&plusmn;0.33%) followed by oleic acid (21.8&plusmn;0.40 %) as the most abundant unsaturated FAs found in the OL, respectively.<br> <strong>Conclusions: </strong>These results demonstrated that OL is a rich source of natural and bioactive compounds, which can be used in the food industry, animal feed, and so on for improving the nutritional value and functionality.</p> Olive leaves, Polyphenol compound, Antioxidant activity, Fatty acids profile 39 46 http://nfsr.sbmu.ac.ir/browse.php?a_code=A-10-570-1&slc_lang=en&sid=1 Yadollah Jabalbarezi Hukerdi yadollahbarezi@gmail.com 10031947532846003153 10031947532846003153 No Department of Animal Science, Faculty of Agriculture, University of Birjand, Birjand, Iran Mohammad Hassan Fathi mhfathi@gmail.com 10031947532846003154 10031947532846003154 No Department of Animal Science, Faculty of Agriculture, University of Birjand, Birjand, Iran Ladan Rashidi l.rashidi@stanard.ac.ir 10031947532846003155 10031947532846003155 Yes Department of Food and Agriculture, Standard Research Institute, Iranian National Standards Organization (INSO), Karaj, Iran Mehdi Ganjkhanlou ganjkhanlou@ut.ac.ir 10031947532846003156 10031947532846003156 No Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Tehran, Karaj, Iran