Efeitos do processamento na erva-mate, Esmelindro et al.

The essential oil of Eucalyptus sp. presented insecticidal and repellency against Sitophilus zeamais Motschulsky (Coleoptera, Curculionidae). Although from an economic point of view synthetic chemicals are still more frequently used as repellents, natural products (essential oils) have the potential to provide efficient and safer repellents for humans and the environment.

RESUMO Chemical composition and antioxidant and antibacterial activities of clove essential oil (Eugenia caryophyllata Thunb)The search for natural antioxidants and antimicrobials has been a major goal of scientific studies. The main objective of this work was to determine the antioxidant and antimicrobial activities and the minimal inhibitory concentration of clove oil obtained by hydrodistillation. GC-MS analysis identified eugenol as major compound of the essential oil. The oil showed antibacterial activity for almost all tested microorganisms. The minimal inhibitory concentration ranged from 0.2 mg.mL -1 to 0.6 mg.mL -1 . There was a linear correlation between the antioxidant activity and the essential oil concentration. Results showed the potential of Eugenia caryophyllata essential oil as an alternative for the formulation of new food products.

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Recebido em 5/9/08; aceito em 29/4/09; publicado na web em 28/10/09 CAROTENOIDS PRODUCTION: MICROORGANISMS AS SOURCE OF NATURAL DYES. Carotenoids are natural dyes synthesized by plants, algae and microorganisms. Application in many sectors can be found, as food dyeing and supplementation, pharmaceuticals, cosmetics and animal feed. Recent investigations have shown their ability to reduce the risks for many degenerative diseases like cancer, heart diseases, cataract and macular degeneration. An advantage of microbial carotenoids is the fact that the cultivation in controlled conditions is not dependent of climate, season or soil composition. In this review the advances in bio-production of carotenoids are presented, discussing the main factors that influence the microbial production of these dyes in different systems.