Impact of Nisin-Activated Packaging on Microbiota of Beef Burgers during Storage

Abstract

ABSTRACT Beef burgers were stored at 4°C in a vacuum in nisin-activated antimicrobial packaging. Microbial ecology analyses were performed on samples collected between days 0 and 21 of storage to discover the population diversity. Two batches were analyzed using RNA-based denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. The active packaging retarded the growth of the total viable bacteria and lactic acid bacteria. Culture-independent analysis by pyrosequencing of RNA extracted directly from meat showed that Photobacterium phosphoreum , Lactococcus piscium , Lactobacillus sakei , and Leuconostoc carnosum were the major operational taxonomic units (OTUs) shared between control and treated samples. Beta diversity analysis of the 16S rRNA sequence data and RNA-DGGE showed a clear separation between two batches based on the microbiota. Control samples from batch B showed a significant high abundance of some taxa sensitive to nisin, such as Kocuria rhizophila , Staphylococcus xylosus , Leuconostoc carnosum , and Carnobacterium divergens , compared to control samples from batch A. However, only from batch B was it possible to find a significant difference between controls and treated samples during storage due to the active packaging. Predicted metagenomes confirmed differences between the two batches and indicated that the use of nisin-based antimicrobial packaging can determine a reduction in the abundance of specific metabolic pathways related to spoilage. The present study aimed to assess the viable bacterial communities in beef burgers stored in nisin-based antimicrobial packaging, and it highlights the efficacy of this strategy to prolong beef burger shelf life.