title: Antimicrobial Activity of Essential Oils AgainstStaphylococcus aureusin Fresh Sheep Cheese.
abstract: Essential oils (EOs) are aromatic oily liquids extracted from different parts of specific plants, well known especially for their aromatic and antibacterial properties. Nowadays, EOs are exploited in the food sector mainly for their aromatic properties. Thanks to their antimicrobial activity, however, they could also be used as additives to increase the safety and the shelf-life of food products. Aim of this study was to assess the antimicrobial activity ofThymus vulgarisL. oil and ofOriganum vulgareL. oil againstStaphylococcus aureusbothin vitroand on fresh cheese, and to determine whether the use of EOs can modify the microbiological and/or chemical-physical properties of the products. The antimicrobial activity againstS. aureus in vitrowas assessed by preparation of the aromatogram (diffusion in agar test), minimum inhibitory concentration test and minimum bactericidal concentration assessment. Raw sheep milk was experimentally contaminated with a strain ofS. aureusATCC 25922 and was used to produce three types of fresh cheese: without EOs, with thyme and oregano EOs (both EOs at a concentration of 1:1000). The samples were analysed on the day of production, after three and seven days. The results obtained from the tests showed that the concentration ofS. aureusand the counts of lactic flora remained unchanged for all types of cheese. Even the chemical-physical parameters were constant. The results of inhibition tests on the cheese disagree with those relating to thein vitrotests. Most likely this is due to the ability of EOs to disperse in the lipids the food: the higher the fat content is, the lower the oil fraction will be able to exert the antimicrobial activity.
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Simonetta
authors: S
authors: Amatiste
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Daniele
authors: D
authors: Sagrafoli
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Giuseppina
authors: G
authors: Giacinti
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Giulia
authors: G
authors: Rosa
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Virginia
authors: V
authors: Carfora
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Nicla
authors: N
authors: Marri
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Andreana
authors: A
authors: Tammaro
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Emanuela
authors: E
authors: Bovi
authors: Centro di Referenza Nazionale della qualità del latte e dei derivati ovini e caprini, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana , Roma, Italy.
authors: Remo
authors: R
authors: Rosati
keywords: Antimicrobial activity; Essential oils; Soft cheese