Óleo essencial de alecrim pimenta (lippia origanoides kunth) no controle de pseudomonas spp. aderidas em superfície de aço inoxidável

Abstract

Essential oil of rosemary pepper (Lippia origanoides Kunth) in the control of Pseudomonas spp. adhered in stainless steel surface. The experiment was carried out to evaluate the antimicrobial activity of essential oil (EO) extracted from rosemary pepper (Lippia origanoides Kunth) on Pseudomonas cells adhered for 48 h on stainless steel AISI 304 # 4 in the presence of skimmed milk. In the chromatography were detected compounds with antimicrobial action as carvacrol (31%) and thymol (2.8%). In order to determinate the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), potential of transfer, adhesion and sanitizing action of the EO the strain Pseudomonas aeruginosa ATCC 27853 and Pseudomonas sp. isolated from raw milk were used. To both strains used, the MIC was 240 µL·mL-1 and it was not possible to determinate the MBC with the levels tested. The potential of transfer reached values between 8.16 and 8.05 log UFC.cm-2 and counting of cells adhered to the stainless steel of 3.84 and 3.24 log UFC.cm-2 to the standard and isolated strains, respectively. After the sanitizing treatment with 240 µL·mL-1 of EO during 2 and 20 min it was observed the complete elimination of the microbial cell present on the contact surfaces. It was possible to observe that the organic matter interferes in the EO action, demanding higher exposure time to obtain bactericide effect. Besides that, the EO was able to inhibit the bacterial growth after 10 and 20 min of contact with the isolated and standard strains, respectively. Thus, the present study showed that EO of rosemary pepper is efficient in the control of adhesion of Pseudomonas in stainless steel surfaces, material used in milking equipment.