en Food Safety and Hygiene Food Safety and Hygiene Review Review Article <div style="text-align: justify;"><span style="line-height:1;"><span style="font-size:14px;"><span style="font-family:Times New Roman;">Olive oil production represents a major economic activity in Iran. The standard industrial extraction process involves three key steps: (i) crushing of olives to rupture cellular structures and release oil, (ii) malaxation to enhance oil yield through gentle mixing of the olive paste, and (iii) separation of oil from the aqueous and solid residues. In the three-phase centrifugation process, the addition of hot water facilitates oil separation but simultaneously generates large volumes of OMWW and solid waste compounds particularly phenolic substances, making it one of the most environmentally problematic effluents in the agro-industrial sector. Despite these challenges, OMWW is also a rich source of bioactive compounds, including phenolics, tocopherols, and carotenoids, which exhibit antioxidant properties. &nbsp;The valorization of food industry wastes and by-products, therefore, serves a dual purpose: it ensures the effective utilization of waste streams while simultaneously promoting public health. This approach contributes significantly to the development of a sustainable food chain from both environmental and economic perspectives. Polyphenolic compounds recovered from OMWW show great potential for applications in the food, pharmaceutical, and cosmetic industries, thereby reframing OMWW from an environmental burden to a valuable resource. The aim of this review is to investigate various methodologies for the extraction and purification of polyphenolic compounds from wastes and by-products generated during the olive oil production process.</span></span></span></div> Olive oil, Wastewater, Extraction of phenolic, Olive, 0 0 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-683-2&slc_lang=en&sid=1 Ali Ammarlo ali.amarlo@gmail.com 100319475328460016316 100319475328460016316 Yes Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran; Food and Drug Deputy, Zanjan University of Medical Sciences, Zanjan, Iran. Arash Ghaitaranpour a.ghaitaranpour@urmia.ac.ir 100319475328460016317 100319475328460016317 No Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran. Adel Mirza Alizadeh a.alizadeh@zums.ac.ir 100319475328460016318 100319475328460016318 No Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran. Nesa Azimzadeh nesaazimzadeh79@gmail.com 100319475328460016319 100319475328460016319 No Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran.