The obtaining of an antioxidant product based on a Rosmarinus officinalis freeze-dried extract

Abstract

The aim of this study was to obtain a freeze-dried extract with an important antioxidant and antimicrobial effect from Rosmarinus officinalis. The extracts were obtained in a fluidized bed solid extractor and there has resulted that the optimal values of phenols, flavonoids and the highest reduction power were determined when using 70% ethanol as solvent, the antioxidant activity ranging between 90-95%. In case of the freeze-dried product, the maximum antioxidant activity was registered when using 0.2 mg mL-1 powder and the results were optimal as well in case of determining flavonoids, phenols and the reduction power. The antimicrobial effect of the extracts and of the freeze-dried product were quantified by using the Colony Quant software on the strains Escherichia coli CBAB 2, Bacillus cereus CMGB 215, Listeria innocua CMGB 218. An inhibition area of maximum 2 cm resulted when using 70% ethanol as solvent. The optimal inhibitory effect of the freeze-dried product, of around 1.8 cm, was determined by a 0.2 mg mL-1 concentration. © 2010 Asian Network for Scientific Information.