Bioactive (Poly)phenols, Volatile Compounds from Vegetables, Medicinal and Aromatic Plants.

Polyphenols, as well as volatile compounds responsible for aromatic features, play a critical role in the quality of vegetables and medicinal, and aromatic plants (MAPs). The research conducted in recent years has shown that these plants contain biologically active compounds, mainly polyphenols, that relate to the prevention of inflammatory processes, neurodegenerative diseases, cancers, and cardiovascular disorders as well as to antimicrobial, antioxidant, and antiparasitic properties. Throughout the years, many researchers have deeply studied polyphenols and volatile compounds in medicinal and aromatic plants, particularly those associated with consumer's choices or with their beneficial properties. In this context, the purpose of this review is to provide an overview of the presence of volatile and nonvolatile compounds in some of the most economically relevant and consumed vegetables and medicinal and aromatic plants, with an emphasis on bioactive polyphenols, polyphenols as prebiotics, and, also, the most important factors that affect the contents and profiles of the volatile and nonvolatile compounds responsible for the aromatic features of vegetables and MAPs. Additionally, the new challenges for science in terms of improving polyphenol composition and intensifying volatile compounds responsible for the positive characteristics of vegetables and medicinal and aromatic plants are reported.

ANTIMICROBIAL ACTIVITY OF AQUEOUS, ETHANOLIC AND METHANOLIC LEAF EXTRACTS FROM ACACIA SPP. AND Eucalyptus nicholii.

BACKGROUND: In Europe, Acacia and Eucalyptus, originate large amounts of biomass, due to their need by industries and other biological control, that can be used to extract antimicrobial substances. MATERIALS AND METHODS: Foliar aqueous, ethanolic and methanolic extracts of Acacia baileyana (Cootamundra wattle), Acacia dealbata (silver wattle), Acacia melanoxylon (black wattle) and Eucalyptus nicholii (narrow-leaved black peppermint) were assessed for antimicrobial activity against Escherichia coli, Bacillus cereus, Candida albicans and Candida parapsilosis, using the disc diffusion method. RESULTS: Ethanolic extracts from A. baileyana and A. dealbata showed significant (P< 0.05) antimicrobial activity. Concerning the microbial species tested, differences were found in A. baileyana (P< 0.01) and E. nicholii (P< 0.0001) extracts. These two extracts were effective mostly against B. cereus, followed by C. parapsilosis. According to the antimicrobial activity classification, eucalypt and Cootamundra and silver wattles extracts (both water and ethanol) presented good efficacy against B. cereus, a food poisoning agent, and moderate efficacy against the remaining microorganisms. E. coli, a Gram negative, exhibited low sensibility to all foliar extracts. CONCLUSION: A. baileyana, E. nicholii and A. dealbata foliar biomass could be used to develop alternative substances in microbial control.