Facile synthesis and characterizations of antibacterial and antioxidant of chitosan monoterpene nanoparticles and their applications in preserving minced meat.

Chitosan nanoparticles loaded monoterpenes (ChMNPs) were prepared for preservation of minced meat from oxidative changes and growth of microorganisms. Four monoterpenes (limonene, linalool, menthol and thymol) were used to synthesis of four different types of ChMNPs. The physicochemical characteristics of nanoparticles were analyzed using Scanning electron microscopy (SEM) and Zeta potential. SEM showed that the nanoparticles were nearly uniformly shape and size and the zeta potential values ranged between 0.0346 and -0.1690 mV. In vitro antimicrobial activity of Ch, monoterpenes (M) and ChMNPs against Gram (-) bacteria Escherichia coli (ATCC 8739) and Salmonella typhimurium (ATCC 1402) was analyzed using serial dilution test. E. coli was more susceptible than S. typhimurium to these products. ChMNPs exhibited good in vivo antimicrobial and antioxidant property for the minced meat samples during refrigerated storage. Verification of testing hypothesis was performed by assessing a DPPH radical scavenging activity, peroxide value and E. coli reduction of experimental nanoparticles. Significant effects of ChMNPs were observed at 1000 and 2500 mg/kg on the total number of E. coli in meat samples during storage time. The results indicate that ChMNPs can be used to preserve food as antimicrobial agents and to extend shelf life.