Atividade antioxidante e antimicrobiana de extratos microencapsulados de ervas aromáticas

Abstract

The use of aromatic herbs in food preparation is an old habit and nowadays it has increasing due to it healthy benefits. The benefits are justified by the bioactive compounds with antioxidant and antimicrobial activity. The current challenge is to condition those compounds that herbs can be a natural choice to replace the synthetic antioxidants used in industry. This way, the microencapsulation is an alternative for, besides microencapsulate the bioactive compounds, and assign significant effects to the extracts, such as low water activity and easy manipulation. Thus, the objective of this work was to evaluate the antioxidant and antimicrobial activity of microencapsulated ethanolic extracts of the aromatic herbs Rosemary (Rosmarinus officinalis), Basil (Ocimum basilicum), Thyme (Thymus vulgaris) and Sage (Salvia officinalis), all belonging to the family of Lamiaceae. The antioxidant activity was determined by the phenolic compounds content, DPPH radical capturing (expressed as Trolox), ABTS radical capturing, iron reducing power (FRAP) and β-carotene/linoleic acid system autoxidation. The antimicrobial activity was performed against Staphylococcus aureus and Salmonella bongori using microdilution in 96 wells microplates for the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). It was observed that Sage and Rosemary the greatest phenolic compounds and the highest iron reduction capacity. The Basil showed an antioxidant capacity by β-carotene/linoleic acid system of 83,03%, greater than the amount found for the sodium erythorbate (77,27%). The Sage and Rosemary extracts showed inhibit power against the Gram-positive bacteria Staphylococcus aureus, with MIC of 25 mg.mL-1. It can be conclude that the aromatic herbs microencapsulated extracts present considerable antioxidant and antimicrobial activities, being an alternative for the food and pharmaceutical industry.