Origanum vulgare extract as a natural additive in fresh cheese

Abstract

Oregano (Origanum vulgare) is a spice that has in its extracts and essential oils biological activities of interest, such as antimicrobial and antioxidant. These qualities are in line with the increased interest in natural alternatives for preserving foods such as fresh cheese due to its short shelf life. The objective of this research was to evaluate the acceptance, antibacterial and antioxidant activity of the hydroalcoholic extract of O. vulgare incorporated in fresh cheese during cold storage. For this, cheeses were produced with different concentrations of extract (0, 0.5, 1 and 3 g of extract/kg). Acceptance was assessed using a nine-point hedonic scale. The presence of Salmonella was investigated and the enumeration of coagulase-positive staphylococci, mesophilic, psychrotrophic and thermotolerant coliforms was performed in the samples. The antioxidant activity was evaluated in vitro (DPPH and FRAP assays) and directly in the food (measuring the malondialdehyde content). The data revealed a good acceptance of all cheeses regardless of the oregano concentration (mean 7.0 to 7.7). The addition of 0.3 g of oregano extract/kg of cheese promoted the inhibition of thermotolerant coliforms during the storage period. Antioxidant activity was demonstrated in vitro but not verified in the cheese. Foods have a complex composition, and the concentration and proportion of different constituents may have influenced the biological actions of the extract. Thus, further research becomes necessary, with variation in storage time and concentrations to know the action of this extract directly in the food model.