**Effect of the Application of a Green Preservative Strategy on Minced Meat Products: Antimicrobial Efficacy of Olive Mill Wastewater Polyphenolic Extract in Improving Beef Burger Shelf-Life**

**Rossana Roila 1, Beatrice Sordini 2, Sonia Esposto 2,\*, David Ranucci 1,\*, Sara Primavilla 3, Andrea Valiani 3, Agnese Taticchi 2, Raffaella Branciari 1,† and Maurizio Servili 2,†**


**Abstract:** The mincing process of raw meat favors microbial spoilage as well as chemical and enzymatic oxidation processes. In order to limit this degradative process, preservatives are routinely added to minced meat products. The role of olive mill wastewater polyphenolic extract as a replacement for synthetic preservatives in beef burger was assessed. The antioxidant capacity of the extract experimentally added to beef burger was evaluated using the oxygen radical absorbance capacity method (ORACFL) to assess the shelf-life, while the lipid oxidation was measured by thiobarbituric reactive substance (TBAR) determination. The antimicrobial activity was assayed by means of classical methods and predictive microbiology. The experimental addition of polyphenolic extract led to 62% lower lipid oxidation and 58% higher antioxidant capacity; it also successfully modulated spoilage microbial populations with an average growth reduction of 15% on day 7. Results indicate that olive mill wastewater polyphenolic extracts could be added to raw ground beef meat to act as natural antioxidants and to modulate microbial growth.

**Keywords:** microbial spoilage; lipidic oxidation; antioxidant; predictive microbiology; food preservation; food safety; sustainable strategy; by-product reuse; kinetic parameters; *Olea europaea*
