The effects of slaughter weight, breed type and ageing time on beef meat quality using two different texture devices

Physical characteristics of meat texture were measured on the M. longissimus dorsi of 103 entire yearling bulls in terms of the effect of slaughter weight (300 or 550 kg), breed type (double muscle, fast growth, dual purpose and unimproved) and ageing time (1, 7 and 21 days). Live weight, breed and ageing effects were statistically significant for all the Warner–Bratzler variables measured on cooked meat. For compression values (raw meat), live weight had a significant effect at higher compression rates, which were higher in the heaviest animals, and ageing had a significant effect at lower compression rates, which were progressively lower as ageing time increased. Breed effect was significantly different for all compression values. At the highest rates of compression, unimproved and dual purpose breed types had the highest values. At 20% compression, double muscled animals had the lowest values, but only at one day of ageing. The differences between breed types tended to decrease or disappear with longer periods of ageing.     

Influence of cattle breed and ageing time on textural meat quality

An experiment was carried out using 7 month old male calves from four different breeds: 10 Spanish Holstein (dairy), 10 Old Brown Swiss (dual purpose), 10 Limousin (fast growth) and 10 Blonde d'Aquitaine (high muscularity). They were all fed concentrate and cereal straw ad libitum. Animals were slaughtered at usual commercial weights for the Spanish market depending on the growth and precocity of each breed (500 kg liveweight at slaughter for Holstein, 550 kg for Old Brown Swiss, 560 kg for Limousin and 620 kg for Blonde d'Aquitaine, with an age between 13 and 15 months). There were significant differences (P<0.001) among breeds in the quantity of total and insoluble collagen in the Longissimus thoracis and lumborum muscle, but collagen solubility was similar (41–44%), except for muscle from the Old Brown Swiss (33%; P<0.001). Overall, breeds specialized for beef production (Limousin and Blonde d'Aquitaine) had lower values for compression and WB in raw and heated meat, respectively, for ageing periods of less than a week. Ageing had a larger effect on myofibrillar tenderness than breed and tended to eliminate the breed effect on textural variables, as well as individual differences within each breed.     

Influence of breed and ageing time on the sensory meat quality and consumer acceptability in intensively reared beef

The meat market is very concerned about the influence of ageing on beef quality. However, not many studies have analysed the possible influence of the intrinsic factors (individual, age, sex, body condition, breed, etc.), on the development of the ageing process. The purpose of this study was to assess the influence of breed on the sensory characteristics of the meat throughout the ageing time, using a trained sensory panel and a consumer test. Forty entire males of four breeds, which represented different biotypes (dairy: 10 Spanish Holstein; dual purpose: 10 Brown Swiss; meat type: 10 Limousin; high muscularity: 10 Blonde d'Aquitaine) were analysed. Animals were weaned at seven months on average (except Holstein calves, which were weaned earlier), and fed intensively. Each breed was slaughtered at its usual commercial live weight, according to the market requirements. The m. Longissimus thoracis et lumborum (between T6 and L6) was cut, vacuum packaged and aged for 1, 3, 7, 14, 21 and 35 days. Cooked samples were evaluated by 8 panellists and 200 consumers. Breed had a significant influence on tenderness (p<0.001) and on the quantity of residue after chewing for panellists (p<0.01), but there was a significant interaction between breed and ageing time for tenderness. Long ageing times (more than seven days) tend to reduce differences among breeds in textural characteristics. Ageing had a very important effect on tenderness (p<0.01) and also on some odour and flavour characteristics evaluated by the panel. Taking into account the results obtained in the consumer test, the consumption of the Limousin meat may be recommended at shorter ageing times, meanwhile Blonde d'Aquitaine, Holstein and Old Brown Swiss meats would need a longer ageing period to obtain an optimum acceptance by the consumer.     

Effect of transport time and ageing on aspects of beef quality

Forty-eight bulls were transported by road in groups of eight for approximately 30 min, 3 or 6 h in two replicates. After slaughter, steaks from the longissimus dorsi thoracis of all transported animals were analysed in terms of pH, water-holding capacity, myoglobin concentration, texture at 7 and 14 days of ageing (compression and Warner-Bratzler analyses) and colour of the same surface of meat cut at 24 h post-mortem and allowed to bloom for 24 h and 7 d (L^*a^*b^*, chroma and hue). The myofibrillar resistance of the meat from animals transported 30 min was significantly greater at 20% compression (P<0.05). The maximum load and a^*b^* and chroma were all lower for meat aged 14 days.     

The effects of breed and halothane sensitivity on pig meat quality

The effects of halothane sensitivity and breed (Belgian Landrace BL and Landrace L), and their interactions on carcass and meat quality were analysed. Also the effect of breed (Pietrain P, BL, L, Large White LW and Duroc D) on carcass and meat quality was studied in a sample of 153 gilts. Each of the half-carcasses was cut and fully dissected to obtain lean percentage. The following measurements of meat quality were carried out: muscle pH, electrical conductivity (QM) and light scattering (POP). Muscle reflectance (GOFO value), muscle protein solubility (MPS) and intramuscular fat content were also determined. The results obtained in this study revealed the effect of halothane gene on all of the traits studied. The halothane-positive animals showed less fat thickness and more lean percentage in the carcass. The P and BL breeds had more lean percentage in the carcass and a better lean-to-bone ratio compared with L, LW and D. The L breed was intermediate. Stress sensitivity is an important factor affecting the inverse relationship between carcass quality and meat quality. Those breeds free of the halothane gene (LW and D) had the best meat quality. The L breed was in an intermediate position, but more similar to halothane-negative breeds. The Duroc breed had significantly higher intra-muscular fat (>2·0%), required for optimum fresh meat quality and for the production of Spanish dry-cured ham of high quality.     

Effect of transport time on sensorial aspects of beef meat quality

Forty-eight slaughter bulls were transported by road in groups of eight for approximately 30 min, 3 h and 6 h in two replicates. After slaughter and an ageing time of 7 days, steaks from the longissimus dorsi thoracis were tasted by a trained sensory panel in terms of odour, tenderness, residue, juiciness, flavour intensity, flavour quality, and overall liking. Transport time had a significant effect (P<0.05) on meat tenderness and overall liking. The panel preferred meat from animals given the 3-h journey as opposed to the 30 min or 6-h journey and found it was more tender and had a better overall liking.     

Colour of beef heated to different temperatures as related to meat ageing

The effects of ageing (10-12 days at +5°C), thermal treatment (internal temperature, T(i): 45, 60, 75°C) and oxygenation on the colour and some colour related physical and biochemical parameters of beef longissimus dorsi (LD) muscle were studied. The colour components (L(?), a(?) and b(?) values) for the raw and heated LD, both before and after ageing and oxygenation, were instrumentally and sensorily evaluated. Ageing influenced colour components (except b(?) value), specific activity of cytochrome c oxidase (SACCO) and amount of oxygen consumed (AOC). An increase in internal temperature was usually accompanied by a lower SACCO, AOC and total native muscle pigment concentration, as well as a change in all colour parameters. Oxygenation of the raw and heated slices (except T(i)=75°C) led to a less of black colour and a higher of red colour, a(?) and b(?) values.     

Very fast chilling of beef: effects on meat quality

This study investigated the use of capillary gel electrophoresis (CGE) as a method for differentiating between raw mechanically recovered chicken meat (MRM) and hand deboned chicken breast meat (HDM). Twenty samples of MRM were obtained and twenty samples of HDM were prepared in the laboratory. They were extracted and analysed using Prosort? SDS-protein analysis reagent. There were obvious differences in the relative peak areas within the profiles obtained which distinguished raw MRM from raw HDM; specifically, that of haemoglobin was higher in MRM. Using the peak area of haemoglobin and its ratio to other peaks, the technique was tested using composite MRM-HDM mixtures. The results suggest that it is possible to differentiate mixtures containing 7.5% MRM from that of 0% MRM using the CGE method.     

Effect of breed and ageing time on meat quality and sensory attributes of veal calves of the "Ternera de Aliste" Quality Label

The effect of breed, sex and ageing time on carcass, meat and eating quality were examined in 32 calves of the "Ternera de Aliste" Spanish Quality Label. Swiss Brown×Alistano-Sanabresa heifers were mated with Charolais or Limousin bulls in order to study the effect of breed. Bull and heifer calves were slaughtered when they were 6-7 months old. Samples of the M. longissimus dorsi were aged for 3, 5 or 7 days and chemical and sensory analyses were done. The results showed no differences due to sex but Charolais sires produced meat which was more tender, juicier and had more odour intensity with a darker colour than meat of the Limousin sired animals. Ageing influenced both sensory and instrumental hardness, colour and odour intensity. After seven days of maturation the meat from such young animals achieved a high quality.     

Influence of ageing time on the quality of yearling calf meat under vacuum

The objective of this study is to determine the effect of the ageing time on the quality characteristics of yearling calf meat under vacuum. Ninety-six Rubia Gallega yearling calves were used. Samples of the Longissimus thoracis at 1 day post slaughter as a control, and vacuum-packaged for 7, 14 and 21 days were analysed. Colour (lightness, L*, redness, a*, yellowness, b*, hue, H^o, chroma, C*, and pigment concentration), water-holding capacity (expressible juice and cooking losses), pH and toughness were measured. The statistical analysis showed an increase in a*, b*, H^o and C* and a decrease in expressible juice, cooking losses and toughness as the ageing time increased. Discriminant analysis divided the samples into two groups; i.e., 1-day post-slaughter samples and vacuum-packaged samples. Considering vacuum-packaged samples only, canonical discriminant analysis separated the long-ageing samples (21 days) from the short-ageing samples (7 days).     

Breed, slaughter weight and ageing time effects on physico-chemical characteristics of lamb meat

The effects of breed, slaughter weight and ageing time on the meat quality of the three most important Spanish breeds were considered. Two hundred and twenty-five lambs of Rasa Aragonesa-local meat breed-, Churra-local dairy breed- and Spanish Merino were used. Animals (75 of each breed) were slaughtered at three different live weights (10–12, 20–22 or 30–32 kg), and the meat was aged for 1, 2, 4, 8 or 16 days. The meat pH, colour, amount of haem pigments, intramuscular fat, moisture, hydroxyproline content and sarcomere length were measured at 24 h post-mortem. Meat texture was measured by compression after each ageing time. The pH of the samples ranged from 5.50 to 5.58. Meat colour varied with breed and slaughter weight (P ⩽ 0.01), the M. longissimus thoracis was lighter in the youngest animals and in the Churra breed and redder in Merinos. Intramuscular fat increased and moisture decreased for heavier lambs. Differences in collagen were associated with breed (P ⩽ 0.01); total and insoluble collagen contents were higher in the Churra breed. Sarcomere length was only slightly affected by slaughter weight. Meat from the Churra breed had the highest values at high levels of compression. Suckling lambs (10–12 kg) had greater myofibrillar toughness than heavier lambs and ageing strongly influenced myofibrillar tenderness.     

Effect of ageing time on quality characteristics of different bovine muscles

This study assessed the impact of the ageing period on the sensory qualities and physical properties of muscles derived from animals obtained by crossing dairy cattle with Limousin meat breed animals. The materials consisted of five muscles – the musculus semitendinosus, musculus semimembranosus, musculus longissimus thoracis, musculus longissimus lumborum and musculus gluteus medius – which underwent the ageing process in a vacuum at 2 °C ± 1 °C. In the case of the raw muscles, the colour, pH and the extent of drip loss was determined. In the case of the grilled muscles, a sensory evaluation was conducted and the texture was instrumentally evaluated. The results showed that the musculus semitendinosus achieved the greatest improvement in positive sensory characteristics due to 14 or 21 days of ageing, which may extend its culinary utility. Among the tested muscles, the musculus longissimus thoracis and lumborum and musculus gluteus medius showed the highest culinary utility after 14 and 21 days of ageing.     

不同日粮水平和成熟时间对牛肉质量的影响

对3组未去势公牛分别采用不同日粮水平饲养并按照标准的屠宰工艺屠宰,对具有代表性的牛肉切块(背最长肌、腰大肌、半膜肌、臀中肌、臂三头肌、半腱肌)的质量的指标如滴水损失、pH值、颜色、蒸煮损失、剪切力进行了测定.结果表明,低日粮水平牛肉pH值偏高(P＜0.05),除腰大肌、臀中肌、臂三头肌的剪切力差异显著(P＜0.05)外,对其余各项指标的影响不显著;而成熟时间除了对牛肉的pH值无影响外,对其他各项指标均有显著影响(P＜0.05),随着成熟时间的延长,牛肉的滴水损失、蒸煮损失呈增加的趋势,而剪切力、颜色得分呈降低趋势.且牛胴体主要分割切块对成熟时间的反应不尽相同.     

不同加工方式对鱼肉组织质地影响的研究进展

鱼类是一种风味独特、营养丰富并且平衡性很好的水产品,深受消费者喜爱。质构与食品的外观、风味、营养一起构成食品的4大品质要素。与畜肉相比,鱼肉的组织更加柔软细嫩,这主要和鱼肉的化学组成有关,随着人们生活水平的提高和食品加工业的发展,鱼肉的组织质地越来越引起人们的重视。本文介绍了几种质构参数,并从物理因素、化学因素和鱼体死后变化3方面分析了影响鱼肉组织质地的各种因素,其中主要介绍了鱼肉肌肉组织的蛋白质组成及其对质构的影响;重点综述了在水产品加工过程中不同加工方式如加热、冷冻、盐渍、烟熏等对鱼肉组织质地的影响,以期为质构分析在产品品质评定中的应用及即食产品的开发和生产提供一定的理论参考,进而更好地满足消费者的需要。     

A modified hot processing strategy for beef: effects on fresh meat quality

A modified hot processing (MHP) strategy for beef carcasses using known chilling technology to maintain quality in the higher priced cuts while retaining lower value cuts for further, immediate hot processing was evaluated. Following high voltage electrical stimulation, paired sides from 36 carcasses were either conventionally processed (CP) or reduced in a manner similar to the French pan traité cut. The sides were help in a pre-chiller for 1 h prior to blast chilling at −20°C for 3 h at an air speed of 2·3 m s⁻¹, followed by chilling at 2°C for the remainder of the 24 h period. Overall, MHP of beef carcass sides had minimal effects on fresh meat quality in the longissimus thoracis et lumborum (LTL) and the semimembranosus (SM) muscles despite removing over 50% of the carcass side weight in the form of lower value cuts. Sarcomere length was significantly shorter (P ≤ 0·05) in the anterior (AL) and posterior (PL) LTL which was attributed to the removal of skeletal restraint and carcass weight. The increase in shear value in the AL, location of MHP sides although statistically significant (P ≤ 0·05) would not likely be percieved by consumers. Hence a non-traditional method of processing carcasses by treating low value and high value primal cuts separately, may be viable.     

不同季节和运输时间对肉鸡应激及肌肉品质的影响

126只白羽肉鸡随机分配到6个处理组,处理因素分别为季节(夏季、冬季)、运输时间(0.5、3、5h),工厂条件宰杀取样,分别测定血液和肌肉指标,研究不同季节和运输时间对肉鸡应激及肌肉品质的影响。数据表明,夏季运输时,随着运输时间的延长,ACTH、CORT、CK、LDH水平呈上升趋势,运输5h肉鸡应激水平达到最大值,此时的GLU含量最低;0.5h运输肉鸡L*值最大,pH最低,保水性最差。冬季运输时,肉鸡3h运输后,ACTH、CORT、CK、LDH水平达到最高,继续运输则其水平下降,其余指标的变化趋势则和夏季运输类似。和冬季运输相比,夏季运输肉鸡血液中的应激指标含量更高,宰后肌肉亮度L*值、滴水损失和蒸煮损失更高,pH较低。结果表明,季节和运输时间可以影响肉鸡的应激水平和肌肉品质,不同的季节应该选择合适的运输时间,从而降低运输应激,提高宰后肌肉品质。      

Combined effects of pre-slaughter treatments and lairage time on carcass and meat quality in pigs of different halothane genotype

The effect of two different lairage times on meat quality was investigated in pigs with different halothane genotype previously submitted to controlled pre-slaughter treatments. One hundred and ninety nine Italian heavy pigs were loaded by ramp or lift and transported unmixed for 1 h to the abattoir at a stocking density of either <0.4 or >0.6 m(2) per 100 kg pigs. After unloading, an equal number of animals within each previous treatment was held in lairage for 2 h or overnight (22 h) before slaughter. Carcass and meat quality and incidence of skin damage were evaluated. Longer lairage did not negatively affect carcass traits and reduced the incidence of PSE meat without increased DFD occurrence. It also seriously increased the amount of skin damage due to fighting, resulting in long fasting. Pre-slaughter treatments and halothane genotype showed a negligible effect on the response to the resting time.     

The effects of electrical stimulation and ageing on beef tenderness

Seventeen beef carcasses from cattle with a range of breeds, ages and body conditions were used in this trial. The four treatments applied to each carcass were control (C), electrical stimulation (ES), ageing for 28 days (A) and electrical stimulation plus ageing for 28 days (ES + A). Post-mortem muscle pH was measured at 0, 0·5, 4 and 24h post-stimulation. Significantly lower muscle pH values (P < 0·01) were achieved by the stimulated carcass side sompared to the unstimulated side at 0·5 (pH 6·47 vs. 6·91) and 4 h (pH 5·96 vs. 6·44) post-stimulation.

Warner-Bratzler shear and taste panel methods were used to assess the tenderness of Longissimus dorsi muscle samples from each of the four treatments. The ES, A and ES + A treatments were significantly more tender (P < 0·01) than the control treatment. The ES and the A treatments resulted in a similar improvement in tenderness compared to the control. The ES + A treatment was significantly more tender (P < 0·01) than the ES treatment alone, but there was no significant difference in tenderness between the A and the ES + A treatments.