Cold-tolerant microorganisms causing spoilage of vacuum-packed beef under time-temperature abuse determined by culture and qPCR

Publikationen als Autor:in / Herausgeber:in der Vetmeduni

Dorn-In, Samart; Schwaiger, Karin

Abstrakt

Vacuum packaging and storage conditions at chilled temperatures are commonly used in order to prolong the shelf life of meat. Under these conditions and time-temperature abuse, cold-tolerant (facultatively) anaerobic spoilage microorganisms can continue growing. This study investigated growth of six relevant spoilage micro-organisms in vacuum-packed beef (n = 12, 72 subsamples, stored at 10 degrees C for 28 days) using culture and qPCR methods. Correspondingly, six qPCRs were newly developed/modified (for total bacteria, lactic acid bacteria (LAB), Enterobacterales, total fungi, Kazachstania psychrophila, and cold-tolerant Clostridium spp.). Besides mi-crobial quantification, four spoilage appearances of meat (gas production, spoilage odor, % drip loss, and meat color) were observed. Results obtained from culture and qPCR show that total bacteria, LAB, and Enter-obacterales reached their stationary phase at day 7 when spoilage parameters such as gas production were statistically increased and a deviation of odor was detected. Fastidious cold-tolerant Clostridium spp. and K. psychrophila could be detected from day 7. Based on microbiological and sensory analysis results, the maximum shelf life of vacuum-packed beef stored at 10 degrees C is 7 days. The developed qPCR has the potential to be used as an alternative method to culturing for determination of microbial growth.

Dokumententyp

Originalarbeit

DOI

10.1016/j.fm.2022.104147

PubMed ID

MEDLINE:36309446