Elaboração de revestimento comestível à base de ora-pronóbis (Pereskia aculeata) e óleo essencial de orégano (Origanum vulgare) aplicado em queijo de coalho

Abstract

The ora-pro-nóbis has become an object of study due to its protein contente, it’s ease of digestion, and the fact is rich in essential amino acids. Based on this purpose, the production of edible coatings using vegetables or their mucilage as raw materials has been reported in the literature. Coalho cheese, along with other dairy products, has an excellent nutritional composition. However, due to these characteristics, they are favorable environments for the growth of microorganisms. In view of this, innovations in food preservation techniques are sought, and the incorporation of edible coatings in food products emerges as a promising preservation method. The objective was to develop and apply an edible coating from the mucilage of ora-pro-nóbis added with oregano essential oil in coalho cheese and evaluate its physicochemical, microbiological and microscopic quality. The experimental design was a 4x4 factorial in triplicate, with 4 treatments (control – cheese without coating; cheese coated with ora-pro-nóbis mucilage; cheese coated with ora-pro-nóbis mucilage + 0.5% oregano essential oil; cheese coated with ora-pro-nóbis mucilage + 1.0% oregano essential oil) and 4 storage periods. The film-forming solutions were prepared and the cheeses were immersed for 30 seconds in the solutions. The cheeses were stored for 15 days under refrigeration conditions (5±1 °C, RH% 50±2). The physicochemical and microbiological analyses were performed at 1, 5, 10 and 15 days. And the microscopy analysis occurred at 1 and 15 days. The results for moisture, ash, pH and water activity showed significant differences (p≤0.05) using the Tukey test. The results for E. coli in the coated cheeses were in accordance with the standards required by Brazilian legislation. In all treatments, the presence of coagulase-positive Staphylococci was observed during storage. Salmonella spp. was absent in 25 grams of all treatments. The coatings adhered well to the curd cheeses, both when made only of ora-pro-nobis and when oregano essential oil was added. Considering its chemical and microstructural properties, ora-pro-nobis mucilage is a promising alternative to biodegradable plastics and edible films.