Abstract: (19632 Views)
Background & Objective: Listeria monocytogenes has already established as an important food born pathogen which induce
listeriosis in human. Use of bacteriocins to provide food safety has been increased dramatically. Nisin has a wide spectrum
inhibitory effect than the other bacteriocins and inhibits food-borne pathogens such as L. monocytogenes and many
other Gram-positive spoilage microorganisms. The purpose of this study was to investigate the inhibitory effect of Nisin on
population of Listeria monocytogenes and the role of changes in food components on the antilisterial properties of Nisin.
Materials & Methods: The minced meat and surimi samples were inoculated by 1×104 cfu/g of L. monocytogenes. Then
samples exposed to Nisin at the levels of 500 or 1000 IU/g were prepared. All treatments after packaging in plastic bags
were kept for 12 days at refrigerator temperature. Samples were cultured on CHROMagarTM Listeria every 2 days and the
number of listeria monocytogenes was counted.
Results: two different concentrations of Nisin (500 or 1000 IU/g) was not able to inhibit L. monocytogenes below the acceptable
level for raw food (100 cells per g) in minced meat and surimi of silver carp. But the number of bacteria reduces
more in fish surimi as compared to the mince meal. Also, antilisterial activity of Nisin was reduced during the storage
period.
Conclusion: Inhibitory property of Nisin against L. monocytogenes in surimi significantly was higher than the minced
(P<0.05). So it is possible the antilisterial properties of Nisin will increase by elimination of some enzymes during processing.
Type of Study:
Research |
Received: 2013/02/11 | Accepted: 2013/09/14 | Published: 2013/09/14