BIOACTIVE PACKAGING WITH PROPOLIS APPLIED IN MINAS STANDARD CHEESE

Active packaging is thin layers of materials that play an important role in the preservation of products. In several studies, extracts with antioxidant potential are incorporated into these coatings to increase the shelf-life and facilitating food processing and consumption. Propolis extract has been widely studied because of its biological actions as antimicrobial and antioxidant. Thus, the objective of this study is to evaluate the inhibitory action of the bioactive packaging against Staphylococcus aureus bacteria in Minas standard cheese. The ethanolic extract of the green and red propolis were prepared for determination of the total phenolic compounds content, using the colorimetric method of Folin-Ciocaulteau described by Singleton and Rossi (1965), with some modifications. Two different methodologies were used to evaluate the antioxidant activity: the ABTS radical deactivation method and the methodology of ORAC, based on the deactivation of the peroxyl radical. The ethanolic extract of green propolis was incorporated into the chitosan biofilm and it was applied in Minas standard cheese to inhibit Staphylococcus aureus. There was a statistical difference in the contents of total phenolic compounds between the types of green and red propolis, with 43,71 and 20,53mg Gallic Acid Equivalent (GAE)/g, respectively. The values were statistically different in the ABTS analysis, with 629.12μmol Trolox Equivalent (TE)/g in the green type and 420.73μmol TE/g in the red propolis. There was no statistical difference in the ORAC methodology between the two types of propolis analyzed, with 436,12 e 520,75 μmol TE/g in green and red propolis, respectively. The bioactive packaging was applied in Minas standard cheese with the intention of inhibiting the growth of bacteria S. aureus at a concentration equivalent to 7,0 x 1013 CFU/mL and the best action was found in the film with incorporation of propolis extract at 12% (v/v). The physical characteristics of chitosan added to chemical and biological properties of propolis allowed the formation of efficient biofilm to inhibit the growth of S. aureus bacteria in the cheese samples. This demonstrates a great potential of this system in the preservation of food, which can increase its shelf-life.