Chemical composition and antimicrobial activity of Cymbopogon citratus and Cymbopogon giganteus essential oils alone and in combination.

As part of ongoing research on the chemical composition and the antimicrobial properties of Burkinabe plants essential oils alone and in combination, essential oils (EOs) from leaves of Cymbopogon citratus and Cymbopogon giganteus from Burkina Faso were analyzed by GC-FID and GC-MS. Five constituents, which accounted for 96.3% of the oil, were identified in the EO of C. citratus. Geranial (48.1%), neral (34.6%) and myrcene (11.0%) were the major constituents. For C. giganteus a total of eight compounds were identified which represented 86.0% of the oils extracted. The dominant compounds were limonene (42%) and a set of monoterpene alcohols: trans-p-mentha-1(7),8-dien-2-ol (14.2%), cis-p-mentha-1(7),8-dien-2-ol (12%), trans-p-mentha-2,8-dien-1-ol (5.6%) and cis-p-mentha-2,8-dien-1-ol (5.2%). The EOs were tested against nine bacteria by using disc diffusion and microdilution methods. C. giganteus EO showed antimicrobial effects against all microorganisms tested whereas C. citratus EO failed to inhibit Pseudomonas aeruginosa. The antimicrobial activity of combinations of the two EOs was quantified by the checkerboard method. Combinations of the two EOs exerted synergistic, additive and indifferent antimicrobial effects. Results of the present investigation provide evidence that the combinations of plant EOs could be assessed for synergistic activity in order to reduce their minimum effective dose.

[Hygienic quality of meat used in institutional food services: university cafeterias in Ouagadougou (Burkina Faso)]. / Qualité hygiénique de la viande utilisée en restauration collective dans trois restaurants universitaires de Ouagadougou (Burkina Faso).

This present study was conducted to assess the hygienic quality of meals served in three cafeterias at the national university in Ouagadougou and the compliance of kitchen staff with good hygiene practices. Microbiological analyses assessed the hygienic quality of the raw meat and of meat-based meals. The results showed poor hygiene practices by food handlers along the food chain. These observations were confirmed by the identification of salmonella, coliform and staphylococcal bacteria in raw meat and cooked meals. Overall, 60% of the raw meat samples were unsatisfactory for aerobic mesophilic flora and 6.6% for salmonella. For the cooked meat meals, on the other hand, 45% of the samples were satisfactory for aerobic mesophilic flora, 100% for salmonella, 93.3% for fecal thermotolerant coliforms and 96.6% for staphylococci. These results showed poor hygiene in the handling of raw meat, but a clear improvement in hygienic quality after cooking. Raising the awareness of cafeteria staff about compliance with hygiene rules appears primordial. Moreover improvement of the food environment, the kitchen equipment, and organization as well as the introduction of a cleaning-disinfection programme would make it possible to provide more hygienic meals in these institutional facilities.