No abstract

No abstract

BackgroundAntimicrobial activity of anthraquinone compounds of emodine type has been reported by many authors. These compounds are found in Vismia laurentii (Clusiaceae), a plant used in traditional pharmacopoeia for treatment of microbial infections among others affections. The continuous identification of new compounds has raised the problem of the relation between the structure and antimicrobial properties.ResultsThe yeast growth kinetics parameters were not influenced by the pH variation as it was the case for the other tested bacteria. Fungicidal activities were noted for all molecules while only few of them had bactericidal activities, mostly on Gram positive bacteria. Mathematical model establishing a quantitative relationship between physicochemical properties of molecules and their fungicidal activities were obtained for Candida albicans and showed that physicochemical properties impacting on antifungal activity were polarizability, partition coefficient, molecular weight and hydrogen bond acceptor.ConclusionsThis work demonstrated that the presence of a long aliphatic chain methoxy group substituted in position two of the emodine structure increased the antibacterial properties of the studied compounds. Moreover this antimicrobial property depends on the pH of the environment, and specifically on the polarizability and number of hydrogen bond acceptors of the compound.

The aim of this work was to characterize the essential oil (EO) of Eryngium foetidum (EfEO) and assess its activity toward Listeria monocytogenes in broth and during thermal inactivation of the pathogen in pineapple juice. In this respect, EfEO was chemically characterized, and its antilisteria potential in broth as a function of pH, cell load, and EfEO concentration was assessed through a central composite design. Furthermore, the inactivation kinetics of L. monocytogenes in the juice were assessed by combining EfEO and low pasteurization temperatures. A total of 81 compounds were identified from EfEO. The reduction of pH and cell load increased EO activity. The use of only 15 ppm of EfEO during pasteurization of pineapple juice at 60°C reduced the time required for a 4-log reduction in L. monocytogenes CFU/ml by 74.9% (i.e., from 8.5 to 2.1 min) compared with treatment without EfEO. It could be concluded that EfEO activity toward L. monocytogenes increases with the reduction of pH and that it can be used at sublethal concentrations in combination with low temperatures in pineapple juice pasteurization. This study demonstrates that EO-assisted pasteurization is a promising strategy for the reduction of thermal impact during juice production. EfEO is easily available and compatible with many juices and is thus promising for industrial application.

No abstract