Fatty acid profile and cholesterol content of beef at retail of Piemontese, Limousin and Friesian breeds.

Samples of longissimus thoracis muscle of young bulls belonging to Piemontese (n=10), Limousin (n=11) and Friesian (n=10) breeds were analysed in order to study the chemical composition, fatty acids and cholesterol content of beef purchased at retail. The breeds and their differences in intramuscular fat content strongly influenced the fatty acids profile. The Piemontese animals displayed the lowest intramuscular fat and SFA content, while Friesian animals showed the highest intramuscular fat, SFA and MUFA content. In general, Limousin animals had intermediate characteristics. A higher PUFA proportion on total fatty acids was observed in Piemontese breed, but the PUFA absolute content (mg/100 g meat) did not differ among breeds. All the three breeds displayed a high content of n-6 fatty acids family and, consequently, a very unbalanced n-6/n-3 ratio. No differences were found for cholesterol content.

Lipomatous muscular 'dystrophy' of Piedmontese cattle.

Lipomatous myopathy is a degenerative muscle pathology characterized by the substitution of muscle cells with adipose tissue, sporadically reported in cattle, pigs, and rarely in sheep, horses and dogs. This study investigated the pathology of this myopathy in 40 muscle samples collected from regularly slaughtered Piedmontese cattle living in Piedmont region (Italy). None of the animals showed clinical signs of muscular disease. Muscle specimens were submitted to histological and enzymatic investigations. Gross pathology revealed a different grade of infiltration of adipose tissue, involving multiple or single muscles. The most affected regions were the ventral abdomen and the shoulders, especially the cutaneous muscles and the muscles of the thoracic group. Morphological staining revealed an infiltration of adipose tissue varying in distribution and severity, changes in muscle fibre size and increased number of fibres with centrally located nuclei, suggesting muscle degeneration-regeneration. Necrosis and non-suppurative inflammatory cells were also seen. Furthermore, proliferation of connective tissue and non-specific myopathic changes were present. Chemical and physical characteristics of the affected tissue were also evaluated. The authors discuss about the aetiopathogenesis and classification of this muscle disorder whose histological lesions were similar to those reported in human dystrophies.

Relationship between beef consumer tenderness perception and Warner-Bratzler shear force.

The aim of this study was to determine consumer ability to discern different levels of beef tenderness established by Warner-Bratzler shear (WBs). A panel of 220 people evaluated 60 samples of longissimus thoracis using a 5-point intensity scale (1: very tough; 5: very tender). Samples differed for commercial category, breed of animals and ageing length of meat. Shear force was measured by Instron equipped with a Warner-Bratzler device on 1.27cm diameter cores. Correlation coefficient of WBs measurements with tenderness sensory ratings was -0.72. WBs value corresponding to class 3 of the sensory tenderness was 47.77N. From this value, the range of WBs (22.96-72.59N) was split into five categories to which connect the five classes of sensory tenderness. The results suggest consumers' difficulty in discriminating category 1 (WBs>62.59N) from category 2 (WBs: 52.78-62.59N) and a greater inclination to distinguish category 5 (WBs<32.96N). As WBs category boundaries were probably too restrictive for the panel's selective ability, WBs scale was reduced to 3 categories by joining the two extreme categories (i.e. category 2 with 1 and category 4 with 5). In this case, 55.6% of consumers significantly discriminated tough from intermediate and tender meat and 62.3% distinguished tender from intermediate and tough meat (P<0.01). Hence, WBs values >52.68N and <42.87N allow classification of tough and tender beef in a sufficiently reliable way.

Single-scan extraction of two-dimensional parameters of infrared focal plane arrays utilizing a Fourier-transform spectrometer.

We present what is believed to be a novel experimental method to measure the technological parameters (spectral response and quantum yield) of an infrared focal plane array. This method makes original use of a Fourier transform spectrometer, which allows us to simultaneously extract the spectral performances of all pixels from one single set of measurements. The methodology used and the principle of the experimental setup are detailed. A Fourier analysis is shown to provide various optogeometrical information on the detector microstructure. A demonstrator based on the HgCdTe technology was designed, and satisfactory experimental results were obtained.

Polymorphism of the GHR gene in cattle and relationships with meat production and quality.

Growth hormone (GH) exerts its effects on growth and metabolism by interacting with a specific receptor (GHR) on the surface of the target cells. Therefore, GHR has been suggested as candidate gene for traits related to meat production in cattle. The aim of the study was to analyse the polymorphism at position 257 in exon 10 of the GHR gene and investigate relationships with 14 in vivo traits and four meat characteristics in Piemontese animals. The biallelic polymorphism already described was detected using a new PCR procedure. The statistical analysis did not show significant gene substitution effects on growth, size and meat conformation traits. As for meat characteristics, a significant gene substitution of GHR(A) over GHR(G) was observed for drip losses at day 3, with the allele GHR(A) associated with higher values. A significant dominance effect was also observed for this trait. Further investigations in other breeds will be useful for better understanding information on the effect of this GHR polymorphism.

Effect of castration on meat quality in Piemontese cattle.

The effect of early (5 month) or late castration (13 month) on meat quality of hypertrophied Piemontese cattle was investigated. Twenty four animals, equally divided into three groups (early castrated, EC; late castrated, LC; intact males, IM) were reared under the same experimental conditions and slaughtered at the same age. Twenty four hours after slaughter the pH was measured on the longissimus thoracis of the right side. After 11 days of ageing the following analyses were performed on the longissimus thoracis et lumborum: water, protein and ether extract contents, hydroxyproline content and collagen solubility, colour (L, a(L), b(L), hue and chroma), drip and cooking losses, Warner-Bratzler shear values and sensory analysis (appearance of the raw meat and eating qualities of the cooked meat). Compared with intact males, the castrates had lower water and hydroxyproline contents and higher contents of protein and ether extract. No significant differences were observed between early and late castration, except for cooking losses.

The use of principal component analysis (PCA) to characterize beef.

Principal component analysis was performed to study the relationships between chemical, physical and sensory variables (n=18) measured on longissimus thoracis et lumborum of 79 young bulls from the following ethnic groups: hypertrophied Piemontese, normal Piemontese, Friesian, crossbred hypertrophied Piemontese×Friesian, Belgian Blue and White. The first three PCs explained about 63% of total variability. Sensory characteristics, protein content, shear force and cooking losses resulted the most effective variables for the PC1, while hydroxyproline and ether extract content, as well as hue and lightness were useful to define the PC2. The distribution of the objects on the axes of the first two PCs allowed the identification of two groups, the first one including meats of the hypertrophied animals (Piemontese and Belgian Blue and White) the second one including normal Piemontese and Friesian. However, a considerable variability within groups was noted. The crossbreds were placed between the two previous groups. In conclusion, PCA proved to be a very effective procedure to obtain a synthetic judgement of meat quality.

Two reading techniques of the filter paper press method for measuring meat water-holding capacity.

Two systems of measuring the areas obtained from the filter paper press method (Grau & Hamm) on meat (beef) were compared: by planimeter (method A) and by optical-electronic system (Video Image Analyzer; method B). Data obtained by three operators, measuring 15 samples twice, were utilized to estimate the 'precision' of the two methods. The general mean area of ring zone resulting from method A was 6·69 cm(2). Analysis of variance demonstrated a significant influence both for 'operator' factor and for the interaction operator-sample. Repeatability and reproducibility were 0·1706 and 0·2580, respectively. By method B the general mean area was 6·67 cm(2). The variance among operators was significant, but lower than in the method A, and there was no interaction. The repeatability and reproducibility were 0·03055 and 0·07234, respectively. It would appear, therefore, that the optical-electronic determination is more precise than the planimetric method.