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Compounds from spices and herbs extracts are being explored as natural antibacterial additives. A plant extract used in traditional folk medicine is Hibiscus sabdariffa L., also known as Roselle. Therefore, the potential use of a phenolic hibiscus extract as antibacterial or natural food preservative was analyzed in vitro and in situ. A phenolic extract was obtained from hibiscus calyces and fractionated, and then the fractions were tested against foodborne pathogen bacteria. Liquid–liquid extraction and solid-phase extraction were used to fractionate the hibiscus extract, and HPLC was employed to analyze the fractions’ phenolic composition. Minimum bactericidal concentration (MBC) and minimal inhibitory concentration (MIC) were calculated for brute hibiscus phenolic extract, each of the fractions and pure commercial phenolic compounds. Bacteria tested were Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The fraction obtained after liquid–liquid extraction presented the best performance of MBC and MIC against the bacteria tested. Furthermore, a hibiscus ethanolic extract was employed as a natural preservative to extend the shelf-life of beef. Microbiological, color and sensory analyses were performed to the meat during the shelf-life test. The application of the phenolic hibiscus extract also showed an increase of the duration of the meat`s shelf life.

The photoinduced bactericidal capacity of TiO(2) based films was evaluated, using as model organism Pseudomonas aeruginosa. Thin films were obtained by spray pyrolysis; they included undoped, Cu doped, and Al doped TiO(2). Scanning electron microscopy was used to observe the final effect of the irradiated films upon the bacteria. Depending on the composition and characteristics of the films, quantitative experiments show that bacterial inhibition varies between 28 and 96%. The order of magnitude of the average quantum yield of the films was determined between 10(-9) and 10(-11) inhibited bacterial per photon.

El nopal (Opuntia spp.), es una cactácea que se encuentra presente en zonas áridas y semiáridas, con gran diversidad de especies y amplia distribución geográfica en México. Por su composición nutrimental, se considera un buen producto alimenticio, así como una buena opción de forraje en zonas desérticas. Se han descrito también muchas propiedades funcionales, incluyendo el contenido de fibra dietética y de pectina, que sugiere su uso como alimento funcional.Además, se han descrito propiedades medicinales, en el control de la diabetes, como antioxidante, antiviral, anticancerígeno y como anticolesterolémico, por lo que es utilizado en la medicina tradicional. Estas propiedades requieren de un estudio a mayor profundidad de la fitoquímica de la planta, así como de los mecanismos de acción involucrados en dichos usos. El presente documento presenta una reflexión sobre lo mucho que se le atribuye al nopal, y lo poco que se ha documentado científicamente sobre el mismo.