Óleos essenciais de plantas condimentares com potencial anti-Shigela flexneri na conservação de carne moída

Abstract

Bacteria of the genus Shigella are Gram-negative bacilli, non-spore forming, belonging to the Enterobacteriaceae family. Shigella sp. is transmitted by contaminated water and food such as salads, raw vegetables, milk and dairy and meat products mainly ground beef and are directly linked to outbreaks of food toxiinfeco rapidly progressive, difficult to treat and easy contagion. The increase in bacterial resistance to sanitizing agents commonly employed in the industry is growing. On the other hand, the chemical preservatives are not well accepted by consumers and therefore naturally occurring antimicrobials are currently of great interest. Essential oils are well known for their antimicrobial properties, and several studies have confirmed its efficiency as both sanitizing and disinfectant or as a preservative. This study aimed to determine the minimum inhibitory concentration (MIC) of essential oils of Origanum vulgare, Myristica fragrans, Thymus vulgaris, Syzygium aromaticum, Rosmarinus officinalis, Ocimum basilicum, Cinnamomum zeylanicume and Foeniculum vulgare dulce against Shiguela flexneri to select oils increased activity to assess the anti-Shiguela potential of combining these oils in contamination of ground beef. The essential oils combined pure and were analyzed by GC and GC-MS. The IMC and combinations of pure essential oils in different concentrations were determined using the technique of microdilution in 96-well polystyrene plates. The essential oils pure and in mixture, were incorporated into the ground meat and then the meat was contaminated with S. flexneri. For bacterial counts dilutions in the 0 h, 24 h and 48 h and plating on medium Shiguela /Salmonella, followed by incubation for 24 h at 35 ° C for counting the colonies were used. The essential oils that showed greater inhibition were Syzygium aromaticum (0.33%) and of Cinnamomum zeylanicum (0.65%). The oils of Thymus vulgaris and Origanum vulgare Myristica fragrans showed MIC in the range from 5 to 10%. The combinations of oils from leaves of Origanum vulgare, leaves and flowers of Thymus vulgaris flower buds of Syzygium aromaticum and Cinnamomum zeylanicum aerial parts were successful in controlling strains of Shigella flexneri, a fact that makes it possible aids in the conservation of ground beef.