Title
The characterisation of Bacillus spores occurring in the manufacturing of (low acid) canned products
Author
Oomes, S.J.C.M.
van Zuijlen, A.C.M.
Hehenkamp, J.O.
Witsenboer, H.
van der Vossen, J.M.B.M.
Brul, S.
TNO Kwaliteit van Leven
Publication year
2007
Abstract
Spore-forming bacteria can be a problem in the food industry, especially in the canning industry. Spores present in ingredients or present in the processing environment severely challenge the preservation process since their thermal resistance may be very high. We therefore asked the question which bacterial spore formers are found in a typical soup manufacturing plant, where they originate from and what the thermal resistance of their spores is. To answer these questions molecular techniques for bacterial species and strain identification were used as well as a protocol for the assessment of spore heat stress resistance based on the Kooiman method. The data indicate the existence and physiological cause of the high thermal resistance of spores of many of the occurring species. In particular it shows that ingredients used in soup manufacturing are a rich source of high thermal resistant spores and that sporulation in the presence of ingredients rich in divalent metal ions exerts a strong influence on spore heat resistance. It was also indicated that Bacillus spores may well be able to germinate and resporulate during manufacturing i.e. through growth and sporulation in line. Both these spores and those originating from the ingredients were able to survive certain thermal processing settings. Species identity was confirmed using fatty acid analysis, 16SrRNA gene sequencing and DNA-DNA hybridisation. Finally, molecular typing experiments using Ribotyping and AFLP® analysis show that strains within the various Bacillus species can be clustered according to the thermal resistance properties of their spores. AFLP® performed slightly better than Ribotyping. The data proofed to be useful for the generation of strain specific probes. Protocols to validate these probes in routine identification and innovation aimed at tailor made heat processing in soup manufacturing have been formulated. © 2007 Elsevier B.V. All rights reserved.
Subject
Biology
Biotechnology
Cluster analysis
Food processing
Molecular phylogenetic characterisation
Spore heat resistance
acid
metal ion
RNA 16S
acidity
article
Bacillus subtilis
bacterial spore
bacterium contamination
canned food
DNA DNA hybridization
fatty acid analysis
food contamination
food industry
food preservation
food processing
gene sequence
Geobacillus stearothermophilus
heat tolerance
molecular typing
nonhuman
phylogeny
ribotyping
RNA gene
sporogenesis
strain identification
survival
validation process
Bacillus
Bacterial Typing Techniques
Cluster Analysis
Colony Count, Microbial
Consumer Product Safety
Fatty Acids
Food Contamination
Food Handling
Food Microbiology
Food Preservation
Germination
Heat
Humans
Phylogeny
RNA, Ribosomal, 16S
Species Specificity
Spores, Bacterial
Bacillus (bacterium)
Bacteria (microorganisms)
To reference this document use:
http://resolver.tudelft.nl/uuid:4345bcff-f306-4531-835c-c54fccb67df3
DOI
https://doi.org/10.1016/j.ijfoodmicro.2007.06.013
TNO identifier
240314
ISSN
0168-1605
Source
International Journal of Food Microbiology, 120 (1-2), 85-94
Document type
article