An Balcaen

Meat quality, fatty acid composition and flavour analysis in Belgian retail beef.

The objective of this study was to evaluate the differences in biochemical, sensorial and quality characteristics of retail beef in Belgium. Four types of beef (Belgian Blue double-muscled, Limousin, Irish and Argentine) and two different muscles (longissimus lumborum and semimembranosus) were bought at the retail level and compared with regard to colour, shear force, collagen content, fatty acid analysis, taste panel evaluation as well as flavour analysis. Belgian Blue and Limousin beef had a paler colour, lower collagen and intramuscular fat contents. Fatty acid profiles were significantly different between the four types, with significantly higher PUFA/SFA and n-6/n-3 ratios for Belgiam Blue and Limousin beef compared to Argentine and Irish beef. There were significant differences between the meat types for taste panel tenderness and shear force, however both measurements did not fully correspond. Flavour analysis by gas chromatography-mass spectrometry as well as sensory analysis demonstrated that Irish and Argentine beef had a higher flavour intensity related to higher contents of volatile compounds. Differences in tenderness and flavour between the meat types were probably affected by differences in ageing time, related to import vs local production of meat.

Effect of linseed feeding at similar linoleic acid levels on the fatty acid composition of double-muscled Belgian Blue young bulls

The effect of including linseed [extruded (EL) or crushed (CL)] instead of whole soybeans (S) in the finishing diet of double-muscled Belgian Blue young bulls on the fatty acid composition of the longissimus thoracis, triceps brachii and subcutaneous fat was investigated. The dietary supply of C18:2n-6 was similar in the three diets, while in the EL and CL diet the supply of C18:3n-3 was equal. No effects of diet on the saturated, monounsaturated and branched chain fatty acids were found. Including linseed in place of whole soybeans increased the total intramuscular n-3 fatty acid content significantly, mainly as C18:3n-3, while no significant effect on the total and individual n-6 fatty acid incorporation was observed in the intramuscular fat. As a consequence of the higher n-3 content, the n-6/n-3 ratio was decreased by linseed feeding. In contrast with the intramuscular fat, the subcutaneous fat showed a significantly increased C18:3n-3 proportion accompanied by a significantly decreased C18:2n-6 proportion when linseed was fed. Diet did not influence the c9t11CLA content in the intramuscular or the subcutaneous fat.

Quantification of fresh meat peptides by SDS–PAGE in relation to ageing time and taste intensity

The extraction and quantification of fresh meat peptides in the molecular weight (MW) range between 3 and 17 kDalton (kDa) was examined, as well as their evolution during post-mortem ageing and their relation to taste intensity. Using a Tricine-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) method, quantification of fresh meat peptides in this MW range was possible. Correlation coefficients higher than 0.98 were found between the absolute amounts of peptides loaded on the gel and the measured amounts expressed as cytochrome c equivalents. In contrast to the extraction in the presence of SDS, extraction with 0.1 N HCl, 3% HClO(4) and 0.9% NaCl only partially recovered peptides present in fresh meat samples in both the 3-10 and 10-17 kDa MW range. A substantial increase in peptide concentration in the 3-17 kDa MW range with time post-mortem in both pork and beef fresh muscle samples was found. For grilled beef longissimus lumborum and semimembranosus samples of different origin and ripening times, both the concentration of the peptides in the 3-10 kDa MW range and the intramuscular fat content were significantly related with taste panel intensity scores, while the correlation with the amount of peptides in the 10-17 kDa MW range was not significant.

Polyphasic identification of Bacillus and Brevibacillus strains from clinical, dairy and industrial specimens and proposal of Brevibacillus invocatus sp nov.

Thirty-three clinical, dairy and industrial isolates of aerobic endospore-forming bacteria which were unreactive in routine identification tests were characterized genotypically by using amplified rDNA restriction analysis (ARDRA), 16S rDNA sequencing and DNA-DNA reassociation, and phenotypically by using fatty acid methyl ester (FAME) analysis, SDS-PAGE of whole-cell proteins, API Biotype 100 assimilation tests and 16 other routine phenotypic tests. Three isolates were identified as strains of Bacillus badius, 12 as Brevibacillus agri, including 3 strains associated with an outbreak of waterborne illness, 4 as Brevibacillus centrosporus and 2 as Brevibacillus parabrevis; 12 strains contaminating an antibiotic production plant were recognized as members of a new species, for which the name Brevibacillus invocatus is proposed, with the type strain LMG 18962T (= B2156T = CIP 106911T = NCIMB 13772T).

Halomonas muralis sp. nov., isolated from microbial biofilms colonizing the walls and murals of the Saint-Catherine chapel (Castle Herberstein, Austria).

A group of seven halophilic strains (optimal growth at 2.5-10.0% NaCl) was isolated from samples of a wall and a mural painting, both heavily contaminated by microbial growth, inside the Saint-Catherine chapel of Castle Herberstein (Austria). The strains were subjected to a polyphasic taxonomic study that included DNA-DNA relatedness studies, DNA base-ratio determinations, 16S rDNA sequence analysis, rep-PCR genomic fingerprinting, fatty acid analysis and phenotypic and biochemical characterization. The data obtained indicate that the strains belong to the genus Halomonas and represent a novel species, for which the name Halomonas muralis sp. nov. is proposed. The type strain is strain LMG 20969(T) ( = DSM 14789(T)).

Brachybacterium fresconis sp. nov. and Brachybacterium sacelli sp. nov., isolated from deteriorated parts of a medieval wall painting of the chapel of Castle Herberstein (Austria).

From two samples of microbial biofilms, damaging the mural paintings at the Saint-Catherine chapel of Castle Herberstein (Austria), four and nine coryneform bacteria were isolated, respectively. A polyphasic taxonomic study of these isolates, including morphological, biochemical and chemotaxonomic characterization, REP-PCR fingerprinting, 16S rDNA sequence analysis, DNA base ratio and DNA-DNA hybridizations, allocated them to the genus Brachybacterium. The isolates of the two samples both represent new species, for which the names Brachybacterium fresconis sp. nov. and Brachybacterium sacelli sp. nov. are proposed. The respective type strains are LMG 20336T (= DSM 14564T) and LMG 20345T (= DSM 14566T).

Multiplex PCR screening of soil isolates for novel Bacillus-related lineages.

A16S rDNA multiplex PCR-based high-throughput protocol is presented to screen bacterial isolates in large amounts for the appearance of novel lineages of bacteria, especially hitherto unknown Bacillus relatives. The 16S rDNAs of 4224 isolates from a comprehensive cultivation campaign were screened for similarity to predominant uncultured soil bacteria. Soil suspensions were plated in serial dilutions on various media. After 2, 4 and 6 weeks, colonies were collected with toothpicks and transferred to microtiterplates for cell lysis and storage plates for subculture. Cell lysis was a simple freeze-heating cycle in distilled water. The multiplex PCR was adapted to operate sufficiently for Gram positives under these conditions. Approximately 10.6% of all picked colonies reacted with a primer targeting a Bacillus fraction containing novel Bacillus benzoevorans-relatives previously detected as predominant soil bacteria by culture-independent studies. From these 446 colonies detected by multiplex PCR, 363 (81.4%) could be successfully used for continued subculture and 16S rDNA sequencing. All identification was done by 16S rDNA sequencing. This revealed that more than 60% of them represented a variety of candidates for potentially new species. Twelve colonies were identified as almost identical matches to 16S rDNA sequences of hitherto uncultured but apparently predominant soil bacteria cloned from directly extracted soil DNA. Also, novel lineages of unpredicted phylogenetic diversity like novel Paenibacillus, Sporosarcina and even Xanthomonads were represented.