Chapters authored
Effect of Sanitizers and Oregano Essential Oils to Reduce the Incidence of Salmonella and Other Pathogens in Vegetables
Part of the book: Salmonella
Antioxidant Capacity and Food Pathogenic Bacteria Inhibition of Citrus limetta and Citrus reticulata
In this study, phenolic compounds in the juice, seed and bagasse of C. limetta and C. reticulata cultivated in Mexico at two ripening stages were determined, and their antioxidant capacities were evaluated using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2′-azin-bis-(3-etilbenzotiazolin-6-sulfonic acid) (ABTS) and oxygen radical absorption capacity test (ORAC) methods, as well as their antibacterial growth inhibition. We found that bagasse had the highest total phenol content and the highest total flavonoid content. The dominant flavonoid, hesperidin, was observed to be the highest in bagasse. Ascorbic acid was analyzed and C. limetta juice and C. reticulata bagasse had the highest contents. Antioxidant capacity showed variations in both, C. limetta and C. reticulata, juices which had the highest ABTS value; C. limetta juice and C. reticulata bagasse had the highest DPPH value; C. limetta juice and C. reticulata bagasse had the highest ORAC value. C. limetta and C. reticulata extracts showed the bactericidal effect at the range of 4–40 mg/mL, assayed against Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enterica and Staphylococcus aureus. Overall, ripeness increased total phenol content (TPC), total flavonoid content (TFC), hesperidin content, antioxidant capacity and bactericidal effect. These results may provide useful information for future utilization of C. limetta and C. reticulata.
Part of the book: Citrus
Essential Oils and Microbial Communication
The World Health Organization highlighted the increase in the resistance to conventional antibiotics for most pathogens and observed also a decrease of the threshold for all mechanisms of cell-cell microbial communication, leading to the formation of biofilms and to the increase of microbial pathogenicity. Scientific community is therefore oriented to the identification and study of alternative substances to antibiotics. In such context, substances of vegetal source, such as essential oils (EOs), always used in traditional medicine, stimulated—particularly in recent decades—the scientific world to discover and identify substances, intended as a mixture or single components capable to fight pathogenic microorganisms. From this point of view, the study of plants is very interesting and offers many interesting ideas and results. This brief chapter describes the basis of the microbial communication, until the formation of biofilm, and some mechanisms through which essential oils, or some of their main components, may decrease or inactivate the complex mechanisms that lead to pathogenicity, both of prokaryotes and eukaryotes.
Part of the book: Essential Oils