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1.
Yearling feeder steers (n = 128), selected to vary in frame size and muscle thickness, were fed for 100, 130 or 160 days and then slaughtered. USDA grade data were collected and cooked rib steaks were evaluated for palatability attributes. Frame size was positively related to carcass weight and longissimus muscle area and negatively related to all fatness measures and to USDA yield grade. Steaks from large-framed steers received the lowest sensory panel ratings for juiciness and overall palatability. Muscle thickness of feeder steers was positively related to all measures of carcass muscling. Steaks from thinly muscled (No. 3) steers received higher ratings for juiciness and overall palatability than did steaks from thickly muscled (No. 1) steers. Large-framed or thickly muscled (No. 1) steers produced the lowest percentages of carcasses with at least Choice quality. Although some statistically significant differences were observed when the data were sorted by frame size or muscle thickness, few real trends were evident that would be of value to cattle feeders.  相似文献   

2.
Bulls (n = 115) of four slaughter ages (9, 12, 15 or 18 months) and of 15 genotypes were studied. In this analysis, each bullock was assigned to one of four breed groups-British and British crosses, Brahman and Brahman crosses. Jersey and Jersey crosses or Holstein and Holstein crosses. Slaughter age had an (P < 0·01) effect on marbling score, longissimus muscle area, fat thickness and yield grade while breed group had an (P < 0·01) effect on marbling score and quality grade. In general, British and British cross bullocks produced carcasses with the thickest subcutaneous fat, the highest marbling score and the highest USDA quality grade while Jersey and Jersey cross bullocks yielded carcasses with the lowest weight, smallest longissimus muscle area and the lowest USDA quality grade of the four breed-type groups. Increases in chronological age (from 9 to 18 months) were generally associated with a decrease in USDA maturity score, and increases in marbling score, USDA quality grade, longissimus muscle area, subcutaneous fat thickness and USDA yield grade. Shear force values decreased as bulls matured from 9 to 18 months of age. The meat from Brahman-type bulls had higher shear force values (P < 0·01) than that from bulls of the other breed groups. Steaks from British-type carcasses received the highest numerical ratings for sustained juiciness and flavor while steaks from the Brahman-type carcasses were assigned the lowest numerical ratings for juiciness. Breed-type had a greater effect on tenderness of bull beef than did chronological age.  相似文献   

3.
Optimum chilling schemes for a two- or three-stage chilling system were developed using a validated heat and mass transfer model and a pattern search algorithm. The optimization was performed for the ambient temperature during each stage for an air velocity of 0·5 m/s and 90% relative humidity. The experiments were conducted to evaluate the effect of the optimum conditions on beef quality after ageing.  相似文献   

4.
Effects of anka rice, nitrite, and phosphate used in surface curing of roast beef on chemical analysis, lipid oxidation, sensory evaluation, physical measurements, and microbial growth after refrigerated storage were studied. TBA values indicated that nitrite retarded lipid oxidation and inhibited development of warmed-over flavor; however, anka rice had a flavor masking effect on oxidation; and phosphate did not improve physical measurements due to surface curing but slightly inhibited oxidation. There was a synergistic effect among anka rice, nitrite, and phosphate in some measurements.  相似文献   

5.
Performance, carcass and palatability characteristics of Longhorn steers were compared with those of cattle currently popular in the United States-Hereford, Angus, Brahman, Holstein, two-breed crossbred (British beef breed crosses) and three-breed crossbred (1 4 dairy , 1 4 British beef and 1 2 European beef ) steers. Steers were fed roughage, then a growing diet (42 days), then a high energy (89% concentrate) diet (153 to 179 days by breed group) and slaughtered, individually, at USDA Choice finish or, failing that, after 186 days on the finishing diet. Data suggest that Longhorns, compared with types of cattle currently used: (1) are less desirable in physical appearance; (2) gain weight less rapidly, reaching the desired finish and slaughter weight as older animals; (3) convert feed to liveweight less efficiently; (4) deposit less subcutaneous fat, more internal fat, but essentially the same amount of intramuscular fat; (5) are as muscular (longissimus muscle area, estimated percentage of carcass muscle, muscle to bone ratio, muscle to fat ratio); (6) are as desirable in USDA quality grade and yield grade and (7) produce beef that is a palatable.  相似文献   

6.
Two experiments were conducted to determine the effects of cryogenic chilling on the carcass shrinkage, meat quality, bacterial condition and palatibility of pork. In experiment I, pork sides were chilled at 1°C (n = 20), or immersed in liquid nitrogen (LN) for 1 or 3 min prior to placement in a 1°C cooler. Muscle temperature in the loin was significantly lower at 2 and 6 h post mortem in treated compared to control sides, and loin muscle pH was higher (P < 0·05) at 6 h post mortem in sides immersed for 3 min in LN. Carcass side shrinkage was reduced from 29·3 g kg(-1) in control sides to 20·9 and 13·5 g kg(-1) in sides dipped in LN for 1 and 3 min. Chilling treatment had no significant effect on the survival of mesophilic bacteria on carcass sides, on meat colour, drip loss, protein solubility or sarcomere length, but sides dipped for 1 min in LN has a higher muscle shear value than control sides. In experiment II, carcass sides from halothane positive (H+) and negative (H-) pigs were conventionally chilled (n = 49), immersed in LN for 3 min (n = 23), or electrically stimulated and chilled in LN for 3 min (n = 26). Similar results for temperature, pH, colour, protein solubility and drip loss in loin muscle were found to those in experiment I. Laboratory taste panel results showed that chilling treatment had no effect on palatability. Genotype produced meaningful differences in most palatability attributes with H+ pigs having less tender, less juicy and less desirable flavour than pork from H- pigs. Laboratory studies with inoculated fresh muscle slices showed that a 3 min immersion in LN resulted in a 10-fold reduction in the aerobic spoilage pseudomonads, but effects upon other spoilage bacteria and potential human pathogens were less pronounced. It was concluded that cryogenic chilling using LN reduced carcass shrinkage during cooling, but had no consistent effects on meat quality, palatability or bacterial numbers on the carcass. In contrast, genotype had a significant effect on most pork quality and palatability attributes.  相似文献   

7.
Beef carcasses (n = 1574) were evaluated at Excel Corp. beef slaughtering facility, Friona, Texas, to determine the effects of implants (double Revalor and Ralgro/Revalor) and biological type (Continental European, Continental European × British and British) on carcass characteristics. No differences (P > 0.05) were found between implants for marbling score, USDA quality grade, adjusted preliminary yield grade, percentage kidney, pelvic and heart fat, or carcass weight. Carcasses from cattle implanted with double Revalor had a larger (P < 0.05) ribeye area and a lower USDA yield grade. No differences were found among breed types for marbling score, USDA quality grade, preliminary yield grade, ribeye area or USDA yield grade (P > 0.05). Steers classed as continental European had the lowest adjusted preliminary yield grade and percentage kidney, pelvic and heart fat, the heaviest carcasses and were most muscular as determined by the Excel muscle score (P < 0.05).  相似文献   

8.
A computer model was used to compare alternative bacon grade schedules in terms of the carcass composition, joint proportions and simple meat quality characteristics (muscle pH and light reflectance) of pigs in different grades. The data used were for 350 side-dissected carcasses from years 6 to 8 of the Meat and Livestock Commission's Commercial Pig Evaluation. Analyses were carried out separately for restricted-fed and ad libitum-fed pigs. Overall means and standard deviations for carcass weight and lean percentage were 64·4 ± 3·19 and 51·5 ± 3·98 (restricted) and 65·1 ± 3·57 and 49·9 ± 4·09 (ad libitum). Alternative schedules were compared against a base schedule, typical of commercial practice in Great Britain and involving the following requirements for the principal grade: a maximum P(2) measurement (taken laterally over the M. longissimus) of 15 mm, maximum mid-line fat measurements (shoulder/loin) of 42 22 mm and a minimum side length of 770 mm. Removal of the shoulder/loin and length requirements increased the proportion of pigs in the principal grade by seven percentage units with little effect on the mean carcass characteristics of pigs in the grade. An extreme tightening of the maximum shoulder/loin measurements to 35 15 mm removed half the pigs from the principal grade and increased the mean carcass lean content and the lean content of individual joints for pigs in the grade by one to two percentage units. Introduction of a minimum muscle thickness measurement of 55 mm had a similar effect. In both cases the effect was partially mediated through a general reduction in fatness and could be achieved by tightening the maximum P(2) fat thickness. None of the changes in grade schedules examined materially altered the mean meat quality characteristics of pigs in the principal grade. The analysis illustrates the complexities involved in using grade thresholds based on a number of correlated measurements. The use of a multiple regression approach, in which carcass lean content and commercial value are estimated from measurements known to contribute significantly to the regression, would simplify the situation considerably.  相似文献   

9.
Commercially slaughtered and dressed beef carcass sides (n=30) were followed through a standard commercial chill unit fitted with a new "Jasca" air humidification system adjusted to provide intermittent water spraying of carcass sides (spray cycle 2 min on, 1 min off) for 15 h. Immediately after dressing, and after 24h in the chill unit, the surface water activity, and the weight of each side was measured, and 5 cm2 samples were recovered from four locations, i.e. rump, flank, brisket and neck on the surface of each side. These samples, and similar samples from control sides (n=30) processed in a standard commercial chill unit, were subjected to microbiological examination by direct and resuscitation counts on plate count agar (PCA), MacConkey agar (MAC) and violet red bile glucose agar (VRBGA). No significant differences were observed between bacterial numbers on test and control samples on each of the above agars, at each sample point/occasion. Comparison of direct and resuscitation counts suggested the presence of substantial numbers of injured cells, at both stages (pre- and post-chill), on test and control sides. After 24 h in chill units, test sides exhibited an average weight loss of 1.36% (+/-0.36%), which is significantly less (P<0.001) than the average weight loss (1.55%+/-0.24%) from control sides. These results suggest that the Jasca spray-chilling system can limit carcass shrinkage (on average by 0.19%) without significantly increasing the surface populations of selected bacterial groups.  相似文献   

10.
Relationships of temperament evaluated at different production stages with growth, carcass characteristics and beef tenderness were determined in Bonsmara crossbred steers managed under commercial managent. Temperament was evaluated at weaning and at initiation of the finishing phase. Steers from a Roswell, NM ranch (n=156) and a Cline, TX ranch (n=21) were stratified at fall weaning by weight and source and randomly allotted to winter ryegrass at Uvalde or Overton, TX followed by feeding in a commercial feedlot near Batesville, TX. Cattle were observed for temperament (escape velocity, EV, m/s; pen and chute temperament score, PTS and CTS) at weaning and upon entry to the feedlot. Cattle were harvested at approximately 7 mm 12th rib fat. Carcass data was taken approximately 36 hrs post-mortem and 2.5cm thick steaks were removed from the 13th rib for Warner-Bratzler shear force (WBS) determination. The only measures of temperament significantly related to performance were EV and PTS. Weaning EV appeared to be more related to feedlot ADG (r=-0.26, P<0.003), ribeye area (r=-0.37, P<0.0008), yield grade (r=0.29, P<0.01) and WBS, r=0.27, P<0.005) than did the later measures of temperament. However, in-feedlot EV was associated with feedlot weights (r=-0.28, P<0.0004). Results of this research suggest temperament, particularly at weaning, is related to feedlot performance, carcass merit, and beef tenderness at a low to moderate level and evaluation of this trait may be a helpful management tool.  相似文献   

11.
Eighty beef crossbred steers with an average weight of 493 kg (4·66 kg SD) were allocated at random to one of five treatments to assess the effects of withholding feed and water on carcass shrinkage and meat quality. The five treatments were: slaughter from the feedlot (T1); and 12, 24, 36 and 48 h periods without feed and water prior to slaughter (T2-5).Weights were taken of the live animal and the carcass to monitor shrinkage along with relevant meat quality measurements. There were no treatment differences (P > 0·05) in initial farm weight, but plant weight shrinkage increased from 31gkg(-1) for T1 to 106 g kg(-1) for T5. Warm carcass weight decreased (P < 0·05) from 278·8 kg for T1, to 270·7 kg for T3 and 261·9 kg for T5. Liver, alimentary tract components, hide and head decreased as a proportion of farm weight as time without feed and water increased. Muscle pH at 6 days post mortem was increased (P < 0·05) in T3-5 compared to T1, with the result that muscle colour became darker, and steaks had less drip loss. Shear values increased (P < 0·05) from 6·3 kg in T1 to 7·7 kg in T4 and T5 indicating an increase in muscle toughness as time without feed and water increased. It was concluded that steers lose live weight rapidly within the first 24 h without feed and water, and that these relatively short periods of time (24 h) can have detrimental effects on carcass shrinkage and muscle quality.  相似文献   

12.
Response surface methodology (RSM) was used to assess the effect of walnut content (W), microbial transglutaminase/sodium caseinate (MTG/C) content and storage time (ST) at 3 °C on water- and fat-binding properties, texture profile analysis and dynamic rheological characteristics of salt-free beef batters. Walnut addition favoured the binding properties and elastic modulus (G′) of raw meat batters (20 °C); however, increasing amounts of walnut caused G′ to decrease at 70 °C. MTG/C had no effect on binding properties, but it did cause increases in the hardness of cooked meat batters and in the rheological properties of both raw and cooked samples. The products formulated with MTG/C and stored for up to 11 days at 3 °C presented good gel-forming ability; however, binding properties were poor, so that other ingredients like walnut were needed to improve the binding properties of the products.  相似文献   

13.
Sixty feeder steers were assigned scores for frame size (small, medium or large) and muscle thickness (No. 1, No. 2 or No. 3), fed for 112 days and slaughtered. Grade data were collected for all 60 carcasses; 12 sides (four from each muscle thickness group) were fabricated into boneless, closely trimmed retail cuts and the 12 rounds from each of these sides were also physically separated into muscle, fat and bone. Marbling score and USDA quality grade varied inversely (P < 0·05) with frame size. Carcass quality grades were: 33·3% Choice; 67·7% Good and 0·0% Standard for small-framed cattle; 30·3% Choice, 42·4% Good and 27·3% Standard for medium-framed cattle and 5·5% Choice, 66·7% Good and 27·8% Standard for large-framed cattle. Analysis of variance showed significant (P < 0·05) differences among all muscle thickness groups in the longissimus muscle area and carcass weight but no difference in yield grade between the No. 1 and No. 3 muscle thickness groups; the larger mean longissimus muscle area of carcasses from steers in the No. 1 muscle thickness group was offset by their heavier carcass weight and their greater thickness of fat over the longissimus muscle. However, when analysis of covariance was used to hold fatness or fatness and frame size constant, the difference in yield grade between muscle thickness groups No. 1 and No. 3 was significant (P < 0·05). Also, carcasses from cattle assigned muscle thickness scores of No. 1, as feeders, had the highest (P < 0·05) muscle to bone ratio of the round (4·1 to 1) while carcasses from cattle assigned thickness scores of No. 3, as feeders, had the lowest (P < 0·05) muscle to bone ratio of the round (3·4 to 1).  相似文献   

14.
Bull calves (n = 49), born at the University of Minnesota West Central Research and Outreach Center (Morris) between March and May 2011, were used to compare growth measurements and profitability of conventional and organic dairy steers. Calves were assigned to 1 of 3 replicated groups at birth: conventional (CONV; n = 16), organic (pasture and concentrate; ORG; n = 16), or organic grass only (GRS; n = 17), and analysis of variables was on a pen basis. Breed groups of calves were Holstein (HO; n = 9); Holsteins (n = 11) maintained at 1964 breed average level; crossbreds (n = 19) including combinations of HO, Montbéliarde, and Swedish Red; and crossbreds (n = 10) including combinations of HO, Jersey, Swedish Red, and Normande. The CONV steers were fed a diet of 80% concentrate and 20% forage. The ORG steers were fed a diet of organic corn, organic corn silage, and at least 30% of their diet consisted of organic pasture during the grazing season. The GRS steers grazed pasture during the grazing season and were fed high-quality hay or hay silage during the nongrazing season. Intakes of a total mixed ration were recorded daily with herd management software. A profit function was defined to include revenues and expenses for beef value, feed intake, pasture intake, health cost, and yardage. The GRS (358.6 kg) steers had lesser total gains from birth to slaughter than ORG (429.6 kg) and CONV (534.5 kg) steers. Furthermore, the GRS (0.61 kg/d) steers had lesser average daily gain from birth compared with ORG (0.81 kg/d) and CONV (1.1 kg/d) steers. The GRS and ORG steers had smaller rib eye area (49.5 and 65.8 cm2, respectively) compared with CONV (75.4 cm2) steers. For profitability, GRS steers had 43% greater profit than CONV steers due to organic beef price premiums and lower feed costs. On the other hand, ORG steers had substantially less profit than CONV steers. The higher cost of production for the ORG steers is due to the extreme high value of organic corn. The results of the current study illustrate the economic potential of alternative strategies for growing and marketing male offspring of organic dairy cattle in the Midwest.  相似文献   

15.
Effects of feeding sodium chlorate on carcass quality, tenderness and color stability were evaluated. Heifers (n=64) were fed chlorate at either 0.01% or 0.05% of body weight (BW) in the last feeding or 0.01% for the last 5d before harvest, while control cattle received no chlorate. During the 12h period between feed withdrawal and transport to the harvest facility, the cattle were provided water containing either no sodium chlorate or sodium chlorate (approximately 30mM). Feed treatments at 0.01% of BW produced higher marbling scores than feeding 0.01% of BW for 5d. However, neither of these treatments produced marbling scores that were different from non-treated controls. Water supplementation increased tenderness in cattle fed 0.01% of BW for 5d, but decreased tenderness in cattle fed 0.05% of BW at the last feeding. Although tenderness differences existed, it is not clear whether or not they were caused by the feed or water treatments or by pre-existing variation in the cattle. Neither feed nor water supplementation affected color stability. These data suggest that chlorate preparations could be used to reduce pathogens without adversely impacting meat quality or display life. However, further research is needed to further substantiate these findings.  相似文献   

16.
A beef processing strategy for improving energy and labour efficiencies, modified hot processing (MHP), was developed in a research abattoir. The work reported herein investigated carcass chilling rates and electrical energy usage in the chilling of carcasses that were processed using this approach. The MHP procedure removes the lower value cuts from the dressed carcass along with associated bone and fat. The remaining high value meat (posterior carcass quarter) is chilled in the usual manner, while the low value cuts are immediately processed (e.g. reduced into pre-blended, salted, chilled meat for emulsion-type products; rendered; directly processed as fresh, hot-boned meat, etc.). Carcasses prepared by the MHP method were dissected to quantify the amounts of lean meat, separable fat and bone removed in the procedure. These data were used with a simple model to predict the amount of chilling energy that could be saved by applying MHP prior to chilling. Electrical power to operate a blast chilling facility containing carcasses that had been processed either by conventional processing or by MHP methods was monitored and recorded, and the resulting data was used to confirm the model result. The MHP procedure reduced the refrigeration load for beef chilling by as much as 51% (P < 0·05). The amount of chilling energy to be saved would depend upon the methods employed to further process the low value tissues, and was calculated to be no less than 7%. The time for the reduced MHP carcass quarters to chill to 10°C at the fat-muscle interface of the longissimus dorsi muscle (12/13 rib) was shorter for MHP carcasses than for conventional carcasses (5·77 h vs 7·08 h, respectively) (P < 0·05). However, the times to chill the deep hip location of MHP hind quarters and conventional beef sides were not significantly different (P < 0·05).  相似文献   

17.
Kim CJ  Lee ES 《Meat science》2003,63(3):397-405
The effects of quality grade (which reflects relative marbling) on the chemical, physical and sensory properties was investigated using Korean native cattle (Hanwoo) beef. Thirty-six Hanwoo cows were slaughtered and the carcasses were graded at 24h postmortem according to the Korean carcass grading system. The quality grade 1 (high quality), grade 2 and grade 3 (low quality) were based on the marbling score of longissimus dorsi (LD) muscles. The effects of quality grade on the meat quality parameters of beef LD muscle were assessed during aging. Loin-eye area, fat thickness and yield grade were all similar for the three quality groups. Mean lean color, fat color and maturity scores did not differ among quality grade groups (P>0.05). pH, Sarcomere length, WHC, collagen content, cooking loss, shear force and MFI were not affected by quality grade groups. Drip loss for grade 1 group was significantly lower than that for grade 3 groups (P<0.05). At initial tenderness evaluation of steaks, no differences among the three grades were observed; however, with additional days of storage, grade 1 steaks had higher tenderness score than grade 3 steaks (P<0.05). Increased postmortem aging time improved tenderness attributes regardless of quality groups. No significant differences were found among the quality grade groups for flavor (P>0.05). The grade 1 group had the highest juiciness score, and grade 3 groups had the lowest score (P<0.05), but postmortem aging did not influence flavor and juiciness. The quality grades were more strongly related to juiciness than tenderness or flavor.  相似文献   

18.
Twenty red deer carcasses were included in the study. Two treatments were applied to the carcasses; control (air chilling) and spray chilling (n = 10 for each treatment). Carcass weight and temperature change were registered during over-night chilling. Meat moisture content was measured in the shoulder, loin, flap and leg before and after the chilling treatments; purge, cooking loss and tenderness were measured in loin samples stored at −1.5 °C for 3 and 9 weeks. Microbiological status was assessed on swabs taken at the lumbar end of the loin before and after the chilling treatments. Spray chilling reduced carcass weight loss significantly; air chilled and spray chilled carcasses lost 1 kg and less than 0.01 kg, respectively. No effects of spray chilling on tenderness, purge and cooking loss were found. Bacterial levels were low in general even after 9 weeks of vacuum packaged chilled storage.  相似文献   

19.
《Meat science》2011,87(4):926-930
Twenty red deer carcasses were included in the study. Two treatments were applied to the carcasses; control (air chilling) and spray chilling (n = 10 for each treatment). Carcass weight and temperature change were registered during over-night chilling. Meat moisture content was measured in the shoulder, loin, flap and leg before and after the chilling treatments; purge, cooking loss and tenderness were measured in loin samples stored at −1.5 °C for 3 and 9 weeks. Microbiological status was assessed on swabs taken at the lumbar end of the loin before and after the chilling treatments. Spray chilling reduced carcass weight loss significantly; air chilled and spray chilled carcasses lost 1 kg and less than 0.01 kg, respectively. No effects of spray chilling on tenderness, purge and cooking loss were found. Bacterial levels were low in general even after 9 weeks of vacuum packaged chilled storage.  相似文献   

20.
Obuz E  Dikeman ME 《Meat science》2003,65(3):993-997
Biceps femoris and longissimus lumborum steaks were cooked from either a frozen or thawed state on an electric belt grill (TBG-60 MagiKitch'n Inc., Quakertown, PA) at 93?°C to the endpoint temperature of 70?°C. Cooking loss, cooking time, Warner-Bratzler shear force (WBSF), and color (Illuminant A, L(?), a(?), b(?)) were evaluated. Trained panelists (n=6) evaluated palatability attributes on an eight-point scale for myofibrillar tenderness, juiciness, flavor, overall tenderness, and connective tissue amount (1=extremely tough, dry, bland, tough, and abundant; 8=extremely tender, juicy, intense, tender, and none). L(?), a(?), WBSF, juiciness, flavor, connective tissue amount, and overall tenderness did not differ (P>0.05) between steaks cooked from frozen and thawed states. However, thawed steaks cooked faster and had lower cooking losses than frozen steaks. The biceps femoris had higher WBSF values than the longissimus lumborum and was rated less tender by trained panelists. L(?), a(?), or b(?) values did not differ (P>0.05) between muscles. The biceps femoris needed more time to cook and had greater cooking losses than longissimus lumborum. Dimensional changes of steaks cooked to either 60 or 70?°C were studied. The width of biceps femoris steaks decreased 12.2%, and width of longissimus lumborum decreased 6.3%. Longissimus lumborum steaks became shorter (P<0.01) than biceps femoris steaks. Thickness of biceps femoris steaks decreased 25.6%, and thickness of longissimus lumborum steaks decreased 23.3%. Muscle type had a more pronounced effect on dimensional changes of steaks than endpoint temperature.  相似文献   

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