NANOEMULSION-BASED ACTIVE COATING WITH PINK PEPPER ESSENTIAL OIL FOR PRESERVATION OF FRESH CHEESE

Minas Frescal cheese is a popular product and the fourth most consumed type of cheese in Brazil. However, due to its high pH and moisture content, it is highly susceptible to contamination by spoilage and pathogenic microorganisms. Pink pepper essential oil (PPEO) exhibits antioxidant and antimicrobial properties, making it suitable for encapsulation in nanoemulsions and use as active coatings in food preservation. To extend the shelf life of Minas Frescal cheese, a coating based on sodium alginate and PPEO nanoemulsion was applied. The nanoemulsion formulation consisted of 1.0% (w/w) sodium alginate, 0.75% (w/w) sunflower oil, 1.0% (w/w) Tween 80 or Tween 20, and 1.0% (w/w) pink pepper essential oil. Droplet size and polydispersity index of the nanoemulsion-based coatings were evaluated to determine their physicochemical stability and suitability for application on cheese surfaces. The antimicrobial efficiency of the coating was tested against Listeria monocytogenes and Staphylococcus aureus inoculated in Minas Frescal mini cheeses. Additionally, the effects of the coating on the physicochemical properties of the mini cheeses were assessed throughout refrigerated storage. The coating effectively maintained pH, moisture, and acidity levels, while preserving the texture and color of the mini cheeses, demonstrating its potential as a protective barrier against quality deterioration. However, its antimicrobial efficacy was compromised due to the high degree of syneresis and interactions between PPEO components and the cheese matrix, which likely reduced the availability of bioactive compounds. Therefore, this study highlights the feasibility of using a sodium alginate and PPEO nanoemulsion-based coating for maintaining the physicochemical and textural properties of Minas Frescal cheese. Nevertheless, careful evaluation and optimization of the formulation are necessary to improve antimicrobial performance and maximize its potential as an active packaging strategy for fresh cheeses.