Effects of the natural antimicrobial substance from Lactobacillus paracasei FX-6 on shelf life and microbial composition in chicken breast during refrigerated storage

In our previous study, Lactobacillus paracasei FX-6 was isolated from kefir, and a novel bacteriocin with broad spectrum antimicrobial activity was identified from its fermentation. The aim of this study was to investigate the effects of this antimicrobial substance on chicken breast during refrigerated storage, specifically with regards to pH, total volatile base nitrogen (TVB-N), total viable counts (TVC) and sensory evaluation. Our results showed that the shelf life of chicken breast was prolonged for 4 more days after treatment with 100 mg/mL of antimicrobial substance. Significant differences in volatile organic compound (VOC) were found between the control and test groups. Results from high-throughput sequencing showed that Citrobacter and Acinetobacter were the dominant genera in fresh chicken breast. As time in storage increased, Pseudomonas (89.7%), Hafnia-Obesumbacterium (3.1%) and Serratia (2.6%) became the predominant genera in the control group when the meat was spoiled (day 8). However, these predominant bacteria were effectively inhibited by the antimicrobial substance.