Review of Olive Pomace Valorization Techniques: A Sustainable Perspective for the Olive Oil Industry

The process of olive crushing, which is primarily aimed at producing olive oil, generates significant waste materials in the form of olive pomace and olive mill wastewater. Globally, the production of olive pomace is estimated to be around 2.9 million tons, with a substantial portion originating from Morocco, accounting for approximately 600,000 to 700,000 tons. However, the lack of proper waste management practices has raised significant environmental concerns. These waste materials, characterized by high levels of organic matter, cellulose, and nitrogen, are often discharged untreated into the natural environment. This indiscriminate disposal leads to soil, surface water, and groundwater pollution, along with the release of unpleasant odors. The detrimental effects of olive pomace primarily stem from its polyphenol content, which is resistant to biodegradation. However, these waste materials also contain valuable resources, such as organic matter and various nutrients that can be recycled. In recent years, researchers have focused on exploring different valorization methods for olive pomace. Several studies have investigated techniques such as olive oil extraction, combustion, animal feed, adsorbents, thermal insulation, composting, and solid-state fermentation as potential avenues for valorization. The unique physicochemical properties of olive pomace have presented specific challenges in its management within olive mills, necessitating the development of appropriate valorization strategies and methods. The choice of the most suitable techniques for valorization depends on various factors, including the social, agricultural, or industrial context surrounding the olive mills. While certain methods may be mandated by regulations in the sector, it is advisable to consider environmentally friendly approaches for the sustainable management of olive pomace waste.