Comparison of culture-dependent and independent techniques for characterisation of the microflora of peroxyacetic acid treated, vacuum-packaged beef.

The diversity of microflora associated with peroxyacetic acid (POAA) treated and untreated beef was investigated by 16S rDNA gene cloning, DGGE analysis and conventional bacterial cultivation. Following vacuum packaging, POAA treated and untreated meat samples were stored for up to 18 weeks at -1.5 degrees C.

Potential of solid phase microextraction and gas chromatography for quarantine-required detection of wood packaging in shipping containers.

Solid phase microextraction (SPME) coupled with gas chromatography (GC) was used to detect terpene hydrocarbons inside shipping containers entering New Zealand. The utility of this system for the rapid detection of undeclared wood packaging for quarantine purposes was demonstrated. A portable dynamic air-sampling device was built to house a SPME fibre and allow the air from shipping containers to be sampled.

Effects of rigor temperature and electrical stimulation on venison quality.

The effects of rigor temperature and electrical stimulation on venison quality were assessed using venison longissimus dorsi muscle. In the first trial, effect of rigor temperature (0, 15, 25, 30, 35 and 42°C) and time post-mortem (at rigor, 3, 7 and 14 days) on drip and cooking losses, % expressible water (water holding capacity, WHC), sarcomere length, protein solubility, meat tenderness and colour were investigated. In the second trial, the effects of rigor temperature (15 and 35°C), electric stimulation (stimulated or not stimulated) and time (at rigor, 3 and 6 weeks post-mortem) on tenderness and colour were further investigated.

Efficacy of a peroxyacetic acid formulation as an antimicrobial intervention to reduce levels of inoculated Escherichia coli O157:H7 on external carcass surfaces of hot-boned beef and veal.

The efficacy of a peroxyacetic acid formulation (POAA) at reducing Escherichia coli O157:H7 contamination on external carcass surfaces of hot-boned beef and veal with a commercial spray apparatus was determined. Hot-boned external carcass surfaces were inoculated with either a high dose (10(6) CFU/cm2) in fresh bovine feces or with a low dose (10(3) CFU/cm2) in diluent of laboratory-cultured E. coli O157:H7.

Post-mortem metmyoglobin reduction in fresh venison.

The accumulation of metmyoglobin (MetMb) at the surface of meat during storage contributes significantly to its discolouration. Under appropriate conditions it may be possible to utilise residual meat MetMb reducing activity to maintain fresh colour. Venison meat colour stability is poorer compared with other species.

Integrated technologies to enhance meat quality - An Australasian perspective.

Ensuring meat quality attributes meet the requirements of the diverse range of markets is a critical component for the continued success of the New Zealand and Australian meat industries. Developing cost-effective and flexible technologies to help meet this requirement is a central objective of a current Meat and Wool New Zealand and Meat and Livestock Australia funded programme. This initiative was developed three years ago; it is a collaborative programme that involves meat scientists, electrical engineers and commercial meat processors.

Identifying the bacterial community on the surface of Intralox belting in a meat boning room by culture-dependent and culture-independent 16S rDNA sequence analysis.

We examined the bacterial community present on an Intralox conveyor belt system in an operating lamb boning room by sequencing the 16S ribosomal DNA (rDNA) of bacteria extracted in the presence or absence of cultivation. RFLP patterns for 16S rDNA clone library and cultures were generated using HaeIII and MspI restriction endonucleases. 16S rDNA amplicons produced 8 distinct RFLP pattern groups.

Evaluation of molecular methods to determine enterotoxigenic status and molecular genotype of bovine, ovine, human and food isolates of Staphylococcus aureus.

This study evaluated the use of PFGE and single enzyme AFLP techniques for the determination of the genetic relationships between Staphyloccocus aureus isolates from human, bovine, ovine and food related sources and reports the prevalence of 'classic' (sea to see) and 'new' (seg, seh, sei, sej, sem, sen and seo) staphylococcal enterotoxin (se) genes in 92 S. aureus strains. A sub-set of the se genotyping results was confirmed by ELISA and the presence of SE toxin determined in isolates from different sources.

Functional stability of frozen normal and high pH beef.

The functional properties of whole, diced or minced high and normal pH beef were determined after 0, 1, 2, 3 and 7 month's storage. There was no interaction between pH, degree of comminution and storage time for most of the attributes measured. Regardless of storage time or comminution method, high pH meat had significantly (P<0.

Influence of the sigB gene on the cold stress survival and subsequent recovery of two Listeria monocytogenes serotypes.

The influence of serotype and the role of the sigB gene of Listeria monocytogenes during the survival and recovery on different substrates were determined. Wild-type and sigB mutants of two serotypes of L. monocytogenes were inoculated into buffer and onto beef steaks, and incubated at 4 degrees C for 8 weeks during which samples were removed and Listeria numbers determined.

Ultra-fast freezing and low storage temperatures are not necessary to maintain the functional properties of manufacturing beef.

The effects of freezing rates and subsequent storage temperatures on the functional properties of meat were assessed. In the first trial, 24 Semitendinosus muscles were allocated to four freezing treatments to determine the effect of freezing rate alone (no frozen storage) on the functional properties of thawed muscle proteins. In the second trial, the effect of freezing rate, storage temperature and time were determined: 24 semimembranosus muscles were assigned to 30 treatment combinations using an incomplete factorial design with two freezing rates × three storage temperatures × five storage times.

An SNP-based PCR assay to differentiate between Listeria monocytogenes lineages derived from phylogenetic analysis of the sigB gene.

The alternative sigma factor sigB gene is involved in the stress response regulation of Listeria monocytogenes, and contributes towards growth and survival in adverse conditions. This gene was examined to determine if it could be a useful indicator of lineage differentiation, similar to the established method based on ribotyping. The sigB sequence was resolved in four local L.

Effect of diet and fat content on the functional properties of thawed beef.

The effect of animal diet (pasture versus grain) and fat content (1, 15 and 25%) on the functional properties and quality of beef stored for 8 months at -20 °C was determined. After storage, pasture-finished beef had significantly (P<0.001) less malondialdehyde than grain-finished.

Molecular differentiation of clostridia associated with "blown pack" spoilage of vacuum-packed meats using internal transcribed spacer polymorphism analysis.

The 16S-23S rDNA internal transcribed spacer (ITS) polymorphism analysis was assessed for its suitability in rapid discrimination between species of psychrophilic and psychrotolerant clostridia associated with "blown pack" spoilage of vacuum-packed meats. DNA isolated from 10 reference and 20 meat strains of psychrophilic and psychrotolerant clostridia were used as templates in PCR amplification with primers complementary to conserved regions of the 3' end of the 16S rRNA and 5' end of the 23S rRNA genes directly flanking the spacer. The majority of strains showed multi-band ITS patterns when products of spacer amplification were visualised on an agarose gel.

The role of the sigB gene in the general stress response of Listeria monocytogenes varies between a strain of serotype 1/2a and a strain of serotype 4c.

The ability of Listeria monocytogenes to resist many adverse environmental conditions has been attributed in part to activation of the alternative sigma factor sigma(B), encoded by the sigB gene. The ability of this pathogen to survive and grow under stress conditions varies between strains within the species. The current study was undertaken to determine whether the role played by the sigB gene in the stress response varies among strains of different serotypes.

Effect of feeding pasture-finished cattle different conserved forages on Escherichia coli in the rumen and faeces.

The effects of eight different pre-slaughter diets on gut microflora, pH and dry matter were evaluated in 112 slaughter-weight, pasture-finished heifers. Hide dirtiness at slaughter, plasma cortisol, meat pH and stickiness, and liveweight loss, were also examined. The pre-slaughter diets were: 48 h of 100% meadow hay, lucerne hay, red clover hay, perennial ryegrass hay, haylage, haylage supplemented with maize silage, pasture, or 24 h fasting before transport.