B. Panea

Breed type and ageing time effects on sensory characteristics of beef strip loin steaks.

Forty-two yearling males from seven European beef breeds were used to study breed type and ageing time effects on meat sensory quality. Breeds were grouped according to their double muscled condition (DM), dual-purpose condition (Brown Swiss, BS), fast growth rate (FG) and rustic characteristics (RT). Vacuum packaged loin chops were aged for 1, 3, 7, 10, 14 and 21 days at 4°C and evaluated by a trained taste panel. Ageing time had the main influence in all the studied sensorial descriptors. Breed type did not affect juiciness, fibrosity or overall flavour intensity. Interactions between breed type and ageing appeared in global odour intensity, tenderness (p<0.05) and acid flavour intensity (p<0.01). All breed types showed higher tenderness scores as ageing period increased but, comparatively, those with higher scores at an early postmortem period (DM, FG) showed lower scores at a late postmortem time. A possible faster, but shorter and less intensive meat tenderisation rate in animals with double muscled condition, and its particular collagen characteristics, in relation to BS and RT groups, could explain our findings.

Assessment of breed type and ageing time effects on beef meat quality using two different texture devices

Forty-two male yearlings were used to assess the influence of breed type and ageing time on beef texture. Samples of the M. longissimus dorsi of four breed types [double muscled (DM), dual purpose (Brown Swiss, BS), fast growth (FG) and unimproved type (UT)] were aged for 1, 3, 7, 10, 14 or 21 days at 4°C and frozen at -18°C until analysed. Cooked samples (to end-point of 70°C) were assessed using a Warner-Bratzler (WB) device. Raw samples were assessed using a compression device in which transverse elongation was prevented. There were no significant differences in WB values of cooked meat due to breed type, but ageing had a significant (P<0.05) on maximum load. Ageing, but not breed type, had a significant effect on the compression values of raw meat at low compression rates (P<0.001). Compression values, of raw samples, at 80% compression differed significantly (P<0.001) between breed types, but were not affected by ageing. Compression values of raw samples, at 80% compression, were affected by breed type, probably because of genotype differences in the contribution of connective tissue.

Relationship between collagen characteristics, lipid content and raw and cooked texture of meat from young bulls of fifteen European breeds.

Variations in texture were determined for 10 day aged raw and cooked Longissimus thoracis (LT) muscle from 436 bulls of 15 European cattle breeds slaughtered at an age of 13-16 months. Variations in texture were related to differences in pH 24 h post-mortem, sarcomere length, collagen characteristics and lipid content. The shear force of cooked meat samples varied from 43.8 to 67.4 N/cm². Simmental, Highland and Marchigiana cattle had the highest shear force values and Avileña-Negra Ibérica, Charolais, Casina and Pirenaica cattle had the lowest values. Cooked meat toughness showed a weak negative correlation to lipid content (P<0.001) but no correlation to collagen characteristics. Raw meat texture measured by compression correlated positively (P<0.001) with total and insoluble collagen. In conclusion, collagen characteristics showed correlation to raw meat texture but not to cooked meat toughness of LT muscle in European young bulls.

Near-infrared reflectance spectroscopy for predicting chemical, instrumental and sensory quality of beef.

The aim of this study was to assess near-infrared reflectance (NIR) spectroscopy as a tool for determining sensory and texture characteristics of beef. Chemical, instrumental, texture and sensory characteristics were predicted by near-infrared reflectance spectroscopy carried out on longissimus dorsi muscle samples from 190 young bulls. The use of first derivative gave best predictions together with NIR spectra, except for myoglobin and water holding capacity, which had an R(2) of prediction of 0.91 and 0.82, respectively, using visible and NIR spectra. Tenderness was the best-predicted variable (R(2)=0.98) demonstrating the potential of NIR spectroscopy in the prediction of sensory variables. Chemical composition variables and Warner-Bratzler shear force were predicted with an R(2) of prediction of around 0.7, but protein was not predicted with accuracy.

Carcass quality of 10 beef cattle breeds of the Southwest of Europe in their typical production systems

A sample of about 70 young bulls of each of 10 beef cattle breeds from France and Spain, reared in their typical production systems, was studied regarding growth and carcass quality traits. There were large differences between and within breed-systems. The animals slaughtered in Spain weighed between 444 and 551 kg, whereas the range in France was from 610 to 750 kg. Growth showed a linear tendency; the daily weight gain ranging from 1.03 to 1.65 kg/day. Asturiana de los Valles and Pirenaica were, among the Spanish populations, the breed-systems with more muscle (around 75%) and less fat (8-10%) in the carcass, whereas Avilena-Negra Iberica, Morucha and Retinta showed opposite characteristics (60-65% muscle and 17-19% total fat at the 6th rib). Bruna dels Pirineus and Asturiana de la Montana occupied an intermediate position. All of the French breed-systems, Aubrac, Gasconne and Salers surpassed 73% muscle, while the percentage of total fat ranged from 7.6 to 10%. Salers breed-system also showed the longest and thinnest hind-limb. In the wide range of carcass weights studied in this paper, the general relationships among carcass traits were confirmed. Animals with the better conformation were also leaner. Longer carcasses tended to be associated with poor conformation and fatness. Bone content was clearly opposed to carcass conformation and muscle content.

Eating quality of young bulls from three Spanish beef breed-production systems and its relationships with chemical and instrumental meat quality

Sensory characteristics of longissimus thoracis muscle from three local Spanish beef breed-production systems and their relationships with chemical and instrumental meat quality traits were studied. Young bulls of Bruna dels Pirineus (BP; n=69), Avileña-Negra Ibérica (A-NI; n=70) and Morucha (MO; n=70) breeds were reared in their own production systems. MO breed showed the highest water holding capacity and also the highest thawing loss and haem pigment content (P<0.001). No differences in moisture and protein contents were found among breeds. A-NI showed the highest intramuscular fat (IMF, P<0.05) and total collagen (P<0.001) contents, whereas BP showed the lowest IMF content (P<0.05) and the highest collagen solubility (P<0.001). Beef flavour, tenderness and juiciness accounted for the eating quality differences among the three breed-production systems. Meat from A-NI was rated significantly higher (P<0.01) for beef flavour and tenderness than that from BP and MO animals. Furthermore, MO showed the lowest juiciness (P<0.001) which could be due to its higher thawing loss. Within the three breeds, thawing loss was negatively correlated with juiciness and, likewise cooking loss with juiciness and tenderness (P<0.05). The canonical discriminant analysis showed that the three breeds were significantly different (P<0.05) from each other according to sensory attributes, which justifies their involvement in different protected geographical indications (PGI).

Carcass characterisation of seven Spanish beef breeds slaughtered at two commercial weights

A total of 159 bulls representing seven Spanish beef breeds were fed with concentrates, managed in the same conditions and slaughtered at two commercial weights (veal and young-bull). Carcasses were measured and classified in order to characterise the carcass variation in the Spanish beef market and to assess the relationship among carcass measurements and grading. Principal Component Analysis clearly separated commercial types regardless the inclusion of the carcass weight in the input data. Within commercial weights the studied breeds clustered into three groups according to muscular development and carcass classification score: high meat producer breeds (Asturiana de los Valles and Rubia Gallega); medium meat producers (Parda Alpina and Pirenaica); and low meat producers (Avileña, Retinta and Morucha). The perimeter and width of the leg (muscular development) besides the length and width of the carcass basically defined these three carcass types. Conformation was an important trait in explaining variation between breeds because its values were positively correlated with muscular development and carcass compactness.

The effect of breed-production systems on the myosin heavy chain 1, the biochemical characteristics and the colour variables of Longissimus thoracis from seven Spanish beef cattle breeds

The effect of breed-production system on the myosin heavy chain 1 (MHC-I), the biochemical characteristics and the colour variables of longissimus thoracis (LT) from seven beef breeds was studied: Asturiana de la Montaña (AM), Asturiana de los Valles (AV), Avileña-Negra Ibérica (A-NI), Bruna dels Pirineus (BP), Morucha (MO), Pirenaica (PI) and Retinta (RE) (Age at slaughter between 368 and 541 days; carcass weight between 249 and 334 kg). Significant differences between breed-production systems were found for all traits evaluated. LT from the MO, a rustic type breed, was the most oxidative (MHC-I, 39.3%; isocitrate dehydrogenase activity, 52 nmol min(-1) mg(-1); pigment content, 188.4 μg acid haematin g(-1)) and showed a low L* value (32.6) and high a* and C* values (24 and 27.2, respectively). In terms of meat colour (L* and a*) the canonical discriminant analysis separated the breeds into two groups, the AV, the PI and the A-NI (the lightest ones) from the AM and the MO breeds (the reddest and darkest) whereas the BP showed an intermediate position. The RE and the A-NI were distinguished from the others by their high intramuscular fat content. Meat colour was affected by the muscle biochemical traits in the breed-production systems studied.

Characterisation of young bulls of the Bruna dels Pirineus cattle breed (selected from old Brown Swiss) in relation to carcass, meat quality and biochemical traits

Seventy-four young bulls of the Bruna dels Pirineus beef cattle breed were reared in a typical production system and slaughtered at an average age of 381 days and live weight of 541 kg. The animals were evaluated for productive traits, carcass quality, meat quality, eating quality and biochemical characteristics of m. longissimus thoracis (LT). Biochemical measurements included intramuscular fat (IMF) and collagen proportion, haem pigment concentration, lactate dehydrogenase and isocitrate dehydrogenase activities and type I (MHC I) fibre percentage determined by ELISA. Bruna dels Pirineus bulls achieved high growth rates during the fattening period (1.63 kg/day) and showed good carcass quality, with a high dressing-out proportion (607 g/kg, hot carcass), a good conformation score (U; EUROP) and a moderate fatness score (3;1-5). Carcass composition was estimated from the sixth rib joint dissection (682 g/kg lean proportion, 127 g/kg total dissectable fat and 163 g/kg bone). IMF (24.3 g/kg) and MHC I (27.9%) showed high variabilities (CV>30%). Sensory analysis of LT included beef and livery odour and flavour intensity, and overall tenderness and juiciness assessment of loin samples (14-day ageing). Beef odour and flavour were slightly positively correlated with IMF and carcass fatness score (P<0.05). Fatness, MHC I, insoluble collagen and cooking losses tended to affect the livery flavour intensity positively. This variable was significantly higher in meat from bulls of lower carcass quality (i.e. lower conformation score, lower lean proportion; P<0.05) and higher type I fibre percentage. Loin overall tenderness and juiciness were not affected by the biochemical traits studied, however, they were negatively affected by cooking loss (P<0.05).

Influence of feeding systems on cortisol levels, fat colour and instrumental meat quality in light lambs

Forty-eight lambs were fed as follows: GR, lambs and dams grazed perennial pasture; GR+S, the same as GR except that lambs had access to concentrate; DRL-GRE, lambs in drylot and dams in rationed grazing; DRL, lambs with dams were stall-fed. DRL-GRE and DRL lambs were weaned at 45days of age. Lambs were slaughtered when they reached 22-24kg of live weight. Plasma cortisol concentration was determined three times before slaughter. Subcutaneous fat and meat colour, and texture were analysed. The different levels of cortisol did not affect meat quality. Both grazing systems gave yellower subcutaneous fat and redder muscles than drylot lambs. Differences between systems relating to colour and texture of the meat disappeared with ageing time, which supports the idea that grazing systems are a good alternative in order to offer similar meat to that coming from drylot systems to which consumers are accustomed. Subcutaneous fat colour was a suitable method to discriminate between grazing and drylot systems, but not within them.