Nisin-Loaded Chitosan/Alginate Nanoparticles: A Hopeful Hybrid Biopreservative

To improve the deficiencies concerning the physicochemical instability of nisin, a hybrid of nisin at concentration of 450IU/mL with chitosan/alginate nanoparticles was prepared. Antibacterial strength of the hybrid was compared with free nisin against Listeria monocytogenes ATCC 25923 and Staphylococcus aureus ATCC 19117 in ultra filtered (UF) Feta cheese. The effects of nisin and the nisin-loaded nanoparticles on the chemical composition, rheological parameters, color indices and sensory attributes of UF Feta cheese were studied. Antibacterial experiments indicated that the nisin-loaded nanoparticles were able to decrease the populations of S.aureus and L.monocytogenes up to five- and sevenfold on a logarithmic scale in comparison with free nisin, respectively. Sensory acceptance and physicochemical features of UF Feta cheese were also significantly improved using the nisin-loaded nanoparticles as compared with those of free nisin. Overall, greater antibacterial strengths and less undesirable influences of this hybrid than those of free nisin on the original quality of UF Feta cheese would make this hybrid a promising biopreservative in dairy products. Practical Applications This study investigates the use of chitosan/alginate nanoparticles as an auxiliary adjuvant in food preservation process. Considering our former promising antibacterial strength observed for this hybrid against S.aureus in the milk samples and also our new findings, it can be concluded that this hybrid would actually be an effectual potential biopreservative against common foodborne pathogens without any harmful side effects on the original qualities of the assessed dairy products. These outstanding features would be an incentive for further future investigation and probable industrialization of this hybrid as a highly productive biopreservative in food preservation technology.