[Antioxidant, color and antibacterial properties of edible chitosan film incorporated with Zataria multiflora boiss essential oil against Listeria monocytogenes]

ABSTRACT

The film containing antimicrobial agents are a type of active packaging which is mainly designed to control microbial and chemical spoilage of food. The aim of this study was to evaluate the antimicrobial, antioxidant and color properties of chitosan film incorporated with essential oil of Zataria multiflora Boiss [ZEO]. In this experimental study which was conducted at Urmia University of Medical Sciences between 2009-2010, the chemical composition of ZEO was analyzed using GC-MS. Chitosan films containing 0, 0.5, 1 and 2% ZEO, were obtained by casting method and subsequently, total phenol [TP], antioxidant, color [accordance with hunter system [L*[luminosity], * [redness, and b* [yelloweness]] and antimicrobial characteristics of films on Listeria monocytogenes were studied. The collected data was analyzed by the SPSS software. The order of TP for all films in the experiment was 2% ZEO>1% ZEO%0.5% ZEO> unsupplemented chitosan film, respectively. It was also conducted that the antioxidant activity of chitosan films was increased by adding various concentrations of ZEO. These increases were significant for film containing 1% [33.98%] and 2% [37.77%] ZEO [p<0.05]. Regarding the color luminosity [L*] of the chitosan film, results indicated no significant changes by incorporating ZEO, whereas the incorporation of ZEO into films had a significant effect on film yellowness, evidenced by lower b* values. Finally, it was shown that the presence of ZEO in chitosan films significantly modified the anti-listerial activity of chitosan, [p<0.05]. The results indicated that an active film from chitosan could be achieved by incorporating ZEO. Addition of ZEO improves functional and antibacterial characteristics of chitosan film