Effect of weight at slaughter on the volatile compounds of cooked beef from Spanish cattle breeds

The volatile compounds in cooked beef from the local Spanish cattle breeds, Asturiana, Avileña, Parda Alpina, Pirenaica, Retinta, Rubia Gallega, and Morucha, were studied. Bulls were slaughtered at a live weight of 300 and 550 kg and the beef was aged for seven days before cooking. Differences in volatile composition among the breeds were considerable and may contribute to the perception of flavour differences in the cooked beef. Peak area values for dimethyl sulfide, which could be related to cauliflower notes, were highest for the meat from the Pirenaica breed. Levels of the detected volatiles, especially sulfur compounds, in the beef from the Asturiana breed were low-intermediate and were potentially related to blood and liver notes and unpleasant flavours. Avileña stood out among the rustic breeds because of its high values for 1-octene, methylcyclohexane, tetradecane and carbon disulfide, while Retinta displayed high 2,3,4-trimethylpentane levels. The effect of weight at slaughter was influenced by breed, because, except for octane, all the volatile compounds behaved differently according to the breed. Ethanol was characteristic of animals with a high percentage intramuscular fat content, and carbon disulfide was characteristic of animals slaughtered at the lower of the two live weights considered.     

Shelf life of beef from local Spanish cattle breeds stored under modified atmosphere

Beef steaks from six Spanish cattle breeds (Asturiana de los Valles, Morucha, Parda Alpina, Pirenaica, Rubia Gallega and Retinta) were packaged under modified atmosphere (60% O(2), 30% CO(2) and 10% N(2)). Water loss, pH, thiobarbituric acid values (TBA), aerobic plate counts, lactic acid bacteria and Enterobacteriaceae counts, CIE L*a*b* colour values and the sensory properties of odour and colour were recorded before packaging (day 0) and after 5, 10 and 15 days of storage. A significant interaction (P<0.05) between breed and storage time was found for all variables, except water loss. Values of pH were between 5.3 and 5.6; maximum water loss (2.64%) was reached after 10 days of storage; aerobic plate counts, lactic acid bacteria and Enterobacteriacea counts were lower than 10(7) CFU/g, and L* increased with storage time while a* decreased (P<0.05). The maximum shelf life of beef assessed by sensory evaluation (regarding colour and odour degradation) was between days 5 and 10 in meat from Retinta breed and between days 10 and 15 in meat from the other breeds, shelf life was probably limited by lipid oxidation.     

Fatty acid profile of three adipose depots in seven Spanish breeds of suckling kids

Intramuscular, subcutaneous and kidney knob fat depot fatty acid profiles were studied in 104 male suckling kids from seven Spanish breeds: Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, Pirenaica, Malagueña and Murciano-Granadina. Kids were raised in the traditional production system on mother's milk and slaughtered at around 7 kg live weight. Differences were observed between dairy (Malagueña) and meat breeds (Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, and Pirenaica). Malagueña showed higher monounsaturated and conjugated linoleic fatty acid levels than the other breeds. Highest percentages of saturated fatty acids were observed in meat breeds. For intramuscular fat depot, the range for desirable fatty acids was 66.16–72.27% was. The influence of breed on fatty acid profiles of intramuscular, subcutaneous and kidney knob fat depots studied was evident. Intramuscular fat depot is proposed as a differentiating factor between dairy and meat breed goat kids, but not between meat breed kids.     

Carcass composition and meat characteristics of two rabbit breeds of different degrees of maturity

Carcass and meat characteristics of rabbits from two synthetic breeds of different size were compared. Breed R had a higher adult weight and reached slaughter weight 1 week before breed V. Sixty rabbits of each breed were slaughtered when they (approximately) reached the Spanish commercial liveweight of 2 kg in order to compare their carcasses and meat quality. The carcasses were measured and retailed according to the norms of the World Rabbit Scientific Association. Breed R had a considerably more developed liver, a less developed hind part, and a more developed thoracic cage. Dissectible fat content was 3.1% and 2.5% of the carcass weight for the breeds V and R, respectively. Meat content was higher in the V breed than in the R breed (53 and 51% with respect to the chilled carcases). The ratio meat bone was better for breed V (2.18 and 2.05, respectively). Muscular fat content, estimated in the meat of one side of the carcass, was higher for breed V. All these differences are related to the lower degree of maturity of breed R at equal weights. Muscular pH, measured on the B. femoris and on the M. Longissimus lumborum at the level of the 5th lumbar vertebra, was the same for both breeds. Colour was measured on the carcass surface and in cuts of the M. Longissimus lumborum. Some colour differences were found for the carcass surface, but not for the meat.     

Physico-chemical characteristics of carcass and meat Manchego-breed suckling lambs slaughtered at different weights

Forty-nine Manchego-breed lambs raised exclusively on their dams' milk until slaughter were used in this study. The effects of gender and slaughter weight (10, 12 and 14 kg) on carcass fatness, meat quality and the fatty acid composition of their fat were studied. Fatness, and in particular dorsal-fat thickness (P?0.01), increased with live weight. The effect of gender was even greater (P?0.001), as female lambs presented the highest fatness values for all parameters studied. The smallest drop in m. longissimus pH values was seen in the lowest-weight (10 kg) lambs. These same lambs displayed the highest L(?) value and thus the lightest colour. Fatty acid composition, which was not influenced by live weight, was affected by gender. The subcutaneous fat of female lambs contained more linolenic acid (C18:3) (P?0.01) and a greater proportion of polyunsaturated fatty acids than that of male lambs (P?0.001). Likewise, the intramuscular fat of female lambs displayed a greater proportion of monounsaturated fatty acids (P?0.001) than that of male lambs.     

Physico-chemical characteristics of carcass and meat Manchego-breed suckling lambs slaughtered at different weights

Forty-nine Manchego-breed lambs raised exclusively on their dams’ milk until slaughter were used in this study. The effects of gender and slaughter weight (10, 12 and 14 kg) on carcass fatness, meat quality and the fatty acid composition of their fat were studied. Fatness, and in particular dorsal-fat thickness (P0.01), increased with live weight. The effect of gender was even greater (P0.001), as female lambs presented the highest fatness values for all parameters studied. The smallest drop in m. longissimus pH values was seen in the lowest-weight (10 kg) lambs. These same lambs displayed the highest L* value and thus the lightest colour. Fatty acid composition, which was not influenced by live weight, was affected by gender. The subcutaneous fat of female lambs contained more linolenic acid (C18:3) (P0.01) and a greater proportion of polyunsaturated fatty acids than that of male lambs (P0.001). Likewise, the intramuscular fat of female lambs displayed a greater proportion of monounsaturated fatty acids (P0.001) than that of male lambs.     

Lipid composition of the intramuscular fat of beef from Spanish cattle breeds stored under modified atmosphere

The lipid composition of intramuscular fat from 30 young bulls of 5 Spanish cattle breeds (Asturiana de los Valles, Morucha, Parda Alpina, Pirenaica and Retinta) was studied. Steaks from each shortloin were packaged in 60% O(2), 30% CO(2) and 10% N(2) and aged for 0, 5, 10 and 15 days. Lipid classes obtained by thin layer chromatography and total fatty acids obtained by gas chromatography were evaluated. Meat from Asturiana de los Valles had high PL and C contents, and low TG contents that reflected its low intramuscular percentage content. This breed showed high FFA content that likely originated from lipolysis of PL. The main breed effect was due to the low intramuscular fat content observed in the Asturiana de los Valles. After 5 days, FFA decreased because they were probably transformed into other compounds. The Morucha breed may have a genetic predisposition for depositing MUFA, and the high MUFA and C14:0 values observed in the Morucha breed were likely due to its high intramuscular fat percentage. Regarding fatty acid composition, no "days of storage" effect was observed for any of the studied fatty acids, except for C18:3ω6 that increased during the first 5 days of storage in Asturiana de los Valles. Concerning the fatty acid composition, Asturiana de los Valles had the highest PUFA/SFA ratio, while Parda Alpina and Morucha possessed low ω6/ω3 ratios but high C22:6ω3 contents. Finally, the presence of C22:6ω3 and 15-CH(3)-C16:0 may be related to higher intramuscular fat contents.     

The relationship between the chemical composition of the carcass and the fatty acid composition of intramuscular fat and backfat of several pig breeds slaughtered at different weights

Pigs of Belgian Landrace (B), Duroc (D), Hampshire (H), and Pietrain (P) breeds were slaughtered at 90, 110 and 130 kg body weight (BW) and the carcass chemical composition and fatty acid profiles of intramuscular fat of loin and backfat were determined. The carcass of Pietrain pigs had a higher concentration of protein and less fat than of B, D and H breeds. In tissues, the PUFA:SFA ratio was lower in the heavier (130 kg BW) than in lighter pigs (90 and 110 kg BW). This feature was higher in P pigs compared with the other breeds. The backfat had a higher concentration of PUFA:SFA ratio than intramuscular fat. The PUFA n− 6:n− 3 ratio was not affected by the breed and weight of pigs, but it was lower in backfat than in longissimus muscle fat. The protein concentration in the carcass was positively related to PUFA and negatively to SFA concentration in tissues.     

Colour stability of beef from different Spanish native cattle breeds stored under vacuum and modified atmosphere

Beef steaks from five Spanish cattle breeds were submitted to three packaging conditions: (a) 15 days under vacuum, (b) 15 days under modified atmosphere (MAP) (60% O₂, 30% CO₂ and 10% N₂), and (c) 10 days under vacuum plus 5 days more under MAP. CIE L^*a^*b^* coordinates, chroma (C^*) and hue (H^*), relative concentration of myoglobin, oxymyoglobin and metmyoglobin at the meat surface and sensory evaluation of colour were determined 0, 5, 10 and 15 days after packaging. Beef under MAP showed higher lightness (L^*) and hue (H^*) and lower redness (a^*) and chroma (C^*) than beef under vacuum. Colour of beef under MAP was not acceptable after 15 days of storage, due to the high metmyoglobin concentration. Yellowness (b^*) was the indicator of differences due to ageing and differences in colour between breeds were related to L^*, a^* and H^* values. Packaging conditions had a greater effect on beef colour than breed, but breed differences might change with packaging atmosphere. Both packaging and breed are major factors in packaged beef quality.     

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 Monta?a (AM), Asturiana de los Valles (AV), Avile?a-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.     

我国不同品种黄牛肉质研究概述

我国黄牛品种较多,了解其牛肉本质特性对于优质黄牛资源的开发利用具有重要意义。该文就我国不同品种肉用黄牛及其杂交牛的肉品品质进行了总结,包括其肉色和嫩度等食用品质及蛋白质、脂肪、氨基酸、脂肪酸、矿物质与维生素等营养品质。我国黄牛(尤其是杂交肉牛品种)食用品质较好,具有高蛋白低脂肪、富含矿物质、氨基酸评价优良等特征,但是不同品种之间的脂肪酸的含量及组分等信息匮乏,亟需开展大量的系统性研究工作填补这一空白。     

Performances and meat quality of two Italian pig breeds fed diets for commercial hybrids

The effects of specific diets for commercial hybrids were investigated on 6 Casertana and 11 Mora Romagnola, two endangered Italian pig breeds. Average daily gain (ADG), feed conversion index (FCI), dressing percentage and meat and fat quality of animals bred under similar environmental and nutritional conditions were compared to define their optimal slaughtering weight. Animals were fed the same diets assuming that requirements of Mora Romagnola and Casertana did not differ, and changed every 30 kg of weight gain. ADG and FCI were calculated every 15 days.

Weight gains, divided into 5 groups based on live weight (LW) of animals (60 kg, 60 < kg  90, 90 < kg  120, 120 < kg  160, >160 kg), showed higher values for Casertana than Mora Romagnola, particularly from 121 to 160 kg LW (687 g/d). Average FCI from 50 to 160 kg LW was similar in both breeds (4.2). After 403 days of trial, animals were slaughtered at about 195 kg LW. Carcass measurements showed that Casertana had higher dressing percentage and lean cuts than Mora Romagnola. Both breeds showed extraordinary high ultimate pH values of M. longissimus thoracis (5.96 and 6.15 for Casertana and Mora Romagnola, respectively) M. semimembranosus (6.37 and 6.30), showing an incomplete post mortem glycolysis. Colour of M. longissimus thoracis did not differ between breeds and was particularly dark. Chemical analysis of Casertana meat showed lower percentage of water and fat; the total amount of fatty acids (SFA, MUFA and PUFA) and the SFA/UFA ratio did not show significant differences between breeds.

Results showed that from a growth point of view the optimal slaughtering weight of Casertana and Mora Romagnola should not exceed 160 kg LW. Both breeds had an uncommon reactivity to stress probably due to interactions of genetic, nutritional and management factors.     

Carcass physical and chemical composition of three fat-tailed breeds of sheep

Physical and chemical compositions of carcasses of 73 intact ram lambs of three fat-tailed Iranian breeds; Karakul (K), Mehraban (M) and Baluchi (B) were studied. Lambs were 195 days old at slaughter. Weight of wholesale cuts and bone, fat trim and trimmed meat of each cut were recorded. Moisture, protein, ether extract and ash were determined in each of the deboned cuts. The higher (P < 0·01) proportion of leg and shoulder in K compared with those in the other two breeds was due to a smaller (P < 0·01) tail fat in the former breed. The breeds were not different for weight of wholesale cuts as percentage of tail-free carcases. Tail-free carcass of K lambs had the highest percentage of bone, protein and moisture, and those of M had the highest fat trim and the lowest bone as compared with the other breeds. The small-size Baluchi, which is well adapted to the sub-desert conditions, was the fattest of the breeds, as assessed by its highest ranking for percentage of ether extract in the carcass. On the basis of protein content, the values of M and B tail-free carcasses were 93% and 89% as high, respectively, as that for K. Differences among the breeds for the physical and chemical constituents of wholesale cuts as a percentage of the same component in half carcass without tail were small. On the basis of percentage protein, the values of shoulder, back and flap + neck were 102, 98 and 85% as high, respectively, as that for leg.     

Intramuscular lipid and fatty acid profile of sheep comprising four sex-types and seven slaughter weights produced following commercial procedure

The intramuscular lipid and fatty acid profiles of the m. longissimus dorsi from 84 sheep comprising four sex-types (enire ram, vasectomised ram, wether and ewe) and seven slaughter weights (32, 36, 40, 44, 48 and 52kg) were measured. Animals were reared following the commercial practice. Specifically, they were fed pasture and a concentrate diet, and age at slaughter ranged from 180 to 390 days. Differences between entire and vasectomised rams, and between wethers and ewes in intramuscular lipid content were not significant (P>0.05). However, entire and vasectomised rams were significantly lower (P<0.05) in intramuscular lipid content than ewes and wethers. Sex related differences in 14:0 (myristic acid), t18:1, c18:1, t18:2 and c18:2 proportions were not significant (P>0.05). Ewes and wethers were similar in 16:0 (palmitic acid) and 18:0 (stearic acid) proportions, but ewes contained significantly higher 16:0 and lower 18:0 proportions than entire and vasectomised rams (P<0.01). Entire and vasectomised rams recorded the highest c18:3 proportions, wethers were intermediate whilst ewes contained the lowest proportion (P<0.01). Although neither saturated fatty acid (SFA) nor monounsaturated fatty acid (MUFA) proportions varied with sex-type, vasectomised rams contained significantly higher polyunsaturated fatty acid (PUFA) proportion that the other sex-types (P<0.05). Whilst intramuscular lipid content, and 18:0 and c18:1 proportions were linearly correlated with slaughter weight (P<0.001), 14:0 and c18:3 proportions decreased quadratically with increasing slaughter weight (P<0.001). The vasectomised ram and the entire ram were similar in fatty acid profile, except the significantly higher PUFA proportion recorded by the vasectomised ram.     

Detection of adulterated commercial Spanish beeswax

The physical and chemical parameters (melting point and saponification number), and the fraction of hydrocarbons, monoesters, acids and alcohols have been determined in 90 samples of Spanish commercial beeswax from Apis mellifera L. The adulteration with paraffins of different melting point, cow tallow, stearic acid, and carnauba wax were determined by HTGC-FID/MS detection, and the research was focussed mainly on paraffins and microcrystallines waxes. In general, the added adulterant can be identified by the presence of non-naturally beeswax components, and by the differences of values of selected components between pure and adulterated beeswax. The detection limits were determined using pure and adulterated beeswax with different amounts of added waxes (5%, 10%, 20% and 30%). Percentages higher than 1-5% of each adulterant can be detected in the mixtures. Paraffin waxes were confirmed in 33 of the 90 samples analysed at concentrations between 5% and 30%.     

Conjugated Linoleic Acid (CLA) content of meat from three muscles of Massese suckling lambs slaughtered at different weights

Eighteen Massese male lambs, fed mainly maternal milk were slaughtered at 11, 14 and 17kg. Samples of Longissimus Dorsi (LD), Triceps Brachii (TB) and Semimembranosus (Sm) muscles were collected. Milk from the lamb's dams was sampled weekly. Fatty acid composition of milk and meat was determined. TB was the fattest muscle, Sm the leanest one and LD showed an intermediate value of total lipids, while the weight at slaughter did not influence total intramuscular fat content in any muscle. Although slaughter weight slightly affected overall fatty acid composition of muscles, rumenic acid and total CLA content in TB and Sm, but not in LD, significantly increased with slaughter weight. As regard milk fatty acid composition, the contents of total CLA, RA and others minor CLA isomers decreased during the first four weeks after lambing and then increased at the last control (five weeks). The animals slaughtered at a live weight of 14 and 17kg showed a greater SCD enzyme activity (estimated by product/substrate ratio) and a higher rumen activity (estimated by means of branched chain and odd chain fatty acid content in meat) than animals slaughtered at 11kg. Cis-7, trans-9 CLA content significantly increased with the slaughter age in TB and SM, while trans-7, trans-9 CLA, only increased in TB, and cis-8, cis-10 CLA, only increased in SM. Further studies are needed in order to verify weather the different behaviour of RA in LD muscle may be due to differences in muscle metabolism or fatty acid utilisation.     

四个中国培育品种牛肉涮制适口性研究

为研究中国培育品种牛肉的涮制适口性,该文对6头秦川牛12块分割部位进行了剪切力测定和消费者感官评价,建立了涮食牛肉的嫩度等级评价方法;并对65头夏南牛、中国西门塔尔牛、新疆褐牛和中国荷斯坦牛的13块分割部位的剪切力值进行了测定。结果显示:涮食牛肉的WBSF阈值为<5.13 kg(很嫩),5.14~6.83 kg(嫩),6.84~9.07 kg(中等)和>9.08 kg(韧)。采集的培育品种813个样品,作为涮食牛肉原材料,90.77%样品属于\