Monitoring of spoilage‐associated microbiota on modified atmosphere packaged beef and differentiation of psychrophilic and psychrotrophic strains

• Published in: Journal of applied microbiology 2018-03, Vol.124 (3), p.740-753
• Main Authors: Hilgarth, M., Behr, J., Vogel, R.F.
• Format: Article
• Language: English
• Subjects: Animals; Bacteria - classification; Bacteria - growth & development; Beef; Cattle; Contaminants; Food contamination & poisoning; Food Microbiology; Food packaging; Food Packaging - methods; Hydrogen ions; Leuconostoc; MALDI‐TOF MS fingerprinting; Meat; meat spoilage; Microbiology; Microbiota; Microorganisms; Monitoring; pH effects; Psychrophiles; Red Meat - microbiology; Spoilage; spoilage‐associated psychrophilic/psychrotrophic microbiota; Strains (organisms)
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.13669

Aims This study aimed to explore the discriminatory power of MALDI‐TOF MS as a high‐throughput method to monitor growth dynamics of meat‐spoiling bacteria on modified atmosphere packaged (MAP) beef and to differentiate psychrophilic and psychrotrophic spoilage‐associated strains. Methods and Results MAP beef steaks were incubated for 21 days at constant 4 and 10°C. Development of headspace gas composition, pH, CFU and spoilage‐associated microbial composition were monitored. MALDI‐TOF MS exhibited high discriminatory power for reliable, high‐throughput identification of spoilage‐associated, psychrotrophic microbiota. Microbiota development was highly dependent on initial abundance of specific species. Organoleptic onset of spoilage was concomitant with an alteration of headspace atmosphere and pH. Screening for psychrophiles at 4°C on beef revealed the abundance of Leuconostoc gelidum subsp. gelidum TMW2·1998 with characteristic psychrophilic growth behaviour. Conclusions We suggest that control of initial contaminants is crucial to predict the onset of spoilage and that headspace atmosphere and pH are important parameters with spoilage‐indicative potential. Significance and Impact of the Study MALDI‐TOF MS proved suitable for high‐resolution monitoring of psychrotrophic and psychrophilic spoilage‐associated microbiota and enables improved insights in the spoilage progress. The presence of psychrophilic strains on beef is the likely causative for unexplained spoilage events.