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1.
J Anim Sci ; 82(5): 1471-4, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15144088

RESUMO

In this study, a multi-city, retail consumer survey was used to determine whether marinating in calcium chloride at 72 h postmortem improves consumer and trained sensory panel evaluations of beef loin steaks, Warner-Bratzler shear force (WBSF) values, and the value of CaCl2 marinades to improve tenderness in a national consumer market. Boneless strip loin subprimals (n = 8) were obtained from eight, not electrically stimulated, USDA Standard-grade carcasses, halved, and alternating ends were marinated with 200 mM CaCl2 at 5% (wt/wt) or not injected (controls). Strip loins were then aged for 7 d in vacuum packages at 2 degrees C before WBSF, trained or consumer evaluations. Four trained research teams traveled on the same 7-d period to collect the consumer data. Consumers (n = 393; minimum of 10 consumers/panel, three panels/store, three stores/city, and four cities) varying widely in income level, education, and gender evaluated the steaks for tenderness, beef flavor, juiciness, and overall quality in each of three supermarkets in major cities (Los Angeles, CA; Baltimore, MD; Chicago, IL; and Dallas, TX). The average improvement (P < 0.05) in WBSF for steaks marinated with CaCl2 was 1.39 kg. Trained panelists scored marinated steaks higher (P < 0.05) than control steaks in sustained juiciness (6.00 vs. 5.09), beef flavor (6.31 vs. 5.64), and overall mouth-feel (5.98 vs. 4.93). Consumers also rated marinated steaks higher (P < 0.05) than control steaks in juiciness (5.98 vs. 5.45), beef flavor (6.70 vs. 6.05), tenderness (6.75 vs. 5.89), and overall quality (6.68 vs. 6.20). Consumers in this study would pay dollar 0.95/kg more for steaks marinated with CaCl2, adding dollar 21.64 to the value of a loin from tough carcasses. These results indicate that consumers can differentiate tenderness levels and are willing to pay a premium for calcium chloride marinating to effectively improve the quality of beef loin steaks.


Assuntos
Cloreto de Cálcio/farmacologia , Comportamento do Consumidor , Manipulação de Alimentos/métodos , Carne/normas , Músculo Esquelético/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Baltimore , Bovinos , Chicago , Feminino , Tecnologia de Alimentos , Humanos , Los Angeles , Masculino , Carne/análise , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Paladar , Texas
2.
J Anim Sci ; 81(9): 2213-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12968696

RESUMO

Eight Hampshire x Rambouillet crossbred wethers expressing the callipyge phenotype and eight Hampshire x Rambouillet half-sibling wethers with a normal phenotype were slaughtered when they reached 59 kg. The supraspinatus (SPM), longissimus (LM), and semitendinosus (STM) muscles were analyzed to determine callipyge effects on calpain and calpastatin activities, sarcomere length, percentage of muscle fiber types, and muscle fiber areas. After 14 d of aging, chops were frozen until analyses for trained sensory panel evaluations, Warner-Bratzler shear force values, and consumer perceptions of tenderness, flavor, juiciness, and overall satisfaction of chops were conducted. Calpastatin activity was 57% greater (P < 0.05) and m-calpain activity was 33% greater (P < 0.05) in muscles from carcasses of callipyge than normal sheep. Sarcomeres were shorter (P < 0.001) in the LM than the SPM or STM, regardless of phenotype. Muscle fiber area was 76% larger (P < 0.05) in the LM of callipyge than normal sheep, but muscle fiber area was not affected (P > 0.05) by phenotype in the SPM or STM. Phenotype had no effect (P = 0.12) on the percentage of slow-twitch, oxidative fiber types in any of the three muscles. In STM and LM from callipyge lambs, the percentage of fast-twitch, oxidative/glycolytic fibers was lower (P < 0.05) and that of fast-twitch-glycolytic fibers was higher (P < 0.05) than in their normal counterparts. Phenotype did not affect (P = 0.90) the fiber type percentage in the SPM. Callipyge LM were less tender and normal LM were more tender than other chops (P < 0.05). Callipyge loin chops had higher Warner-Bratzler shear force values than other chops (P < 0.001). Consumers rated fewer (P < 0.05) callipyge loin and shoulder chops acceptable in juiciness, tenderness, and overall acceptability than normal chops, but phenotype did not affect (P > 0.05) consumer acceptability of leg chops. These results indicate that LM from Hampshire x Rambouillet sheep displaying the callipyge phenotype had higher calpastatin activity and were less tender than the LM from normal sheep. In addition, consumer perceptions indicated that only one in 10 leg chops, one in five shoulder chops, and one in four loin chops from callipyge sheep were unacceptable.


Assuntos
Comportamento do Consumidor , Carne/normas , Músculo Esquelético/fisiologia , Ovinos/genética , Animais , Composição Corporal/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Calpaína/metabolismo , Culinária , Inibidores de Cisteína Proteinase/metabolismo , Masculino , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/anatomia & histologia , Fenótipo , Ovinos/fisiologia , Paladar
3.
J Anim Sci ; 81(6): 1464-72, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12817494

RESUMO

Our objectives were to determine the optimal accelerated chill time immediately postmortem necessary to improve the quality of pork muscle and to decrease the incidence of pale, soft, and exudative pork. Carcasses from 81 market hogs were cooled either by conventional chill (CC) at 2 degrees C or by accelerated chill (AC) at -32 degrees C for 60, 90, 120, or 150 min, and then placed into a 2 degrees C cooler for the remainder of the 24-h chill period. Loin muscle pH was higher (P < 0.05) for the carcasses that were accelerated chilled longer than 60 min. Although loin visual color, texture, and firmness scores increased (P < 0.05) with AC time, no improvements were noted beyond 60 min. Color, pH, texture, firmness, and CIE L*a*b* values of fresh ham muscles were not (P > 0.05) affected by AC. In addition, AC did not (P > 0.05) affect purge, drip, or thaw loss of fresh products, sensory scores of loins or processed hams (except initial juiciness; P < 0.05), water-holding capacity of processed hams, or processing characteristics of hams. Cooking loss and Warner-Bratzler shear values for hams and loins were not (P > 0.05) affected by AC. Accelerated chilling caused loins to be darker (lower L* value; P < 0.05) and to have lower (P < 0.05) b* values (less yellow) than CC loins. Accelerated chilling increased water-holding capacity in fresh hams, bound water being the greatest (P < 0.05) in the 120- and 150-min AC groups. These results demonstrate that improvements in pork loin quality can be made using freezer-accelerated chilling for carcasses.


Assuntos
Manipulação de Alimentos/métodos , Congelamento , Carne/normas , Animais , Cor , Concentração de Íons de Hidrogênio , Masculino , Controle de Qualidade , Suínos , Fatores de Tempo
4.
J Anim Sci ; 80(9): 2390-5, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12350016

RESUMO

Boneless top loin subprimals (n = 320) from Slight and Small marbled carcasses were fabricated into 2.54-cm thick steaks to determine core location effects on tenderness. In Exp. 1, top loins were aged to 7 d before steaks were cut and cooked to an internal temperature of 71 degrees C. After cooking, a maximum of 15 1.27-cm diameter cores were removed and sheared with a Warner-Bratzler shear force (WBSF) device. There was not a marbling score x core location interaction (P = 0.36). However, there was a main effect of core location (P < 0.01). Cores from the medial, middle, and lateral portion of the longissimus muscle (LM) aged for 7 d differed, with less resistance (P < 0.05) in the medial than the lateral end. Also, there was an effect of marbling score on WBSF, with Small-marbled steaks having lower (P < 0.02) WBSF values than Slight-marbled steaks. In a second experiment, steaks were removed from the middle of the top loin subprimals and aged an additional 7 d to produce 14-d aged steaks. Shear values decreased (P < 0.05) from Exp. 1 to 2 for all core locations. Neither the main effect of marbling score nor the core location x marbling score interaction was significant (P > 0.40); however, the same lateral to medial gradient in WBSF values was discovered again in Exp. 2. Both experiments indicated there were regions of WBSF values that differed (P < 0.05) across the cross section of the LM producing a shear-force/tenderness gradient, with the most medial cores having the lowest WBSF values in both experiments independent of marbling score. Regression analyses indicated the middle and center portions of LM steaks tended to have the most predictive capacity of average WBSF. Because of the variability in tenderness caused by location within the LM, care should be exercised when selecting sampling areas for the measurements of tenderness using the WBSF measure.


Assuntos
Manipulação de Alimentos/métodos , Carne/normas , Músculo Esquelético/fisiologia , Envelhecimento/fisiologia , Animais , Bovinos , Culinária , Embalagem de Alimentos , Tecnologia de Alimentos , Mudanças Depois da Morte , Distribuição Aleatória , Estresse Mecânico , Fatores de Tempo
5.
J Anim Sci ; 79(9): 2346-55, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11583421

RESUMO

We examined the effects of vitamin and mineral supplementation of the finishing diet on growth and accelerated chilling of carcasses on carcass and muscle traits of halothane gene carrier and noncarrier pigs. Barrows and gilts that were either monomutants (MON, n = 49) or noncarriers (NON, n = 28) of the halothane gene were fed a standard finishing diet until they reached 86 kg. They then were randomly assigned to one of four finishing diets formulated to contain 11 IU/kg vitamin E (0), 311 IU/kg vitamin E plus additional vitamins and minerals (300), 611 IU/kg vitamin E plus additional vitamins and minerals (600), or 911 IU/kg vitamin E plus additional vitamins and minerals (900) until they were slaughtered (118 kg). Alternating carcass sides were assigned either a normal chilling procedure (NC, 4 degrees C for 24 h) or an accelerated chilling procedure (AC, -20 degrees C for 1.5 h and then 4 degrees C for 22.5 h). Supplementing vitamin E in the finishing diet increased (P < 0.05) the concentration of vitamin E in the longissimus muscle. Supplementing vitamin E in the diets of MON pigs did not affect color, firmness, or cooking losses of loins or color and firmness of hams. For the NON genotype, increasing the level of vitamin E in the diet decreased (P < 0.05) the percentage of PSE loins and hams. Color and firmness scores of the gluteus medius and longissimus muscles were improved 0.4 unit (P < 0.005) by AC compared with NC of carcasses. Loin chop juiciness and flavor were improved (P < 0.05) in the MON genotype for AC compared to NC. Accelerated chilling reduced (P < 0.05) the percentage of PSE loins from 38 to 17% and PSE hams from 32 to 10% for the MON genotype, but percentage of PSE was not affected (P > 0.05) by chilling treatment for the NON genotype. No interaction between diet and chill treatments existed for muscle quality traits (P > 0.05). Supplementing finishing diets of NON pigs with at least 600 IU/kg vitamin E, in addition to other vitamins and minerals, or accelerated chilling of MON carcasses can reduce the incidence of PSE pork.


Assuntos
Manipulação de Alimentos/métodos , Carne/normas , Minerais/farmacologia , Suínos/genética , Vitaminas/farmacologia , Animais , Temperatura Baixa , Cor , Feminino , Halotano , Heterozigoto , Masculino , Hipertermia Maligna/genética , Hipertermia Maligna/veterinária , Minerais/administração & dosagem , Músculos/química , Distribuição Aleatória , Fatores de Tempo , Vitamina E/administração & dosagem , Vitamina E/farmacologia , Vitaminas/administração & dosagem , Aumento de Peso
6.
J Anim Sci ; 79(12): 3062-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11811460

RESUMO

In the present study, a national consumer evaluation was conducted for beef tenderness on USDA Select strip loin steaks of known Warner-Bratzler shear (WBS) force values, ranging from tough (> 5.7 kg) to tender (< 3.0 kg), and to assess the monetary value that consumers place on tenderness by determining the average price a consumer would pay for a steak in three tenderness categories. Three supermarkets in each of five metropolitan areas (Baltimore, MD/Washington D.C.; Chicago, IL; Dallas/Fort Worth, TX; Los Angeles, CA; and Lubbock, TX) were selected to represent a wide range of income, education, and ethnicity at each city. Five trained research teams traveled to the cities to collect data during the same 10-d period. Consumers (n = 734; minimum of 15 consumers/panel, three panels/store, three stores/city, five cities) were asked to evaluate samples from each tenderness classification (tender, intermediate, or tough) for overall and tenderness acceptability, overall quality, beef flavor, juiciness, tenderness, how much they would pay for the steak ($17.14, 14.28, or 10.98/kg), if they would pay more than current market price if guaranteed tender, and to estimate the number of meals in a 2-wk period that included beef. The consumers were 52% light beef users, consuming 0 to 8 meals containing beef in 2 wk, 41% heavy beef users (greater than 12 meals/2 wk), and 6% moderate beef users (9 to 12 meals/2 wk). Consumer tenderness acceptability increased as WBS values decreased (P < 0.05). The transition in consumer perception from tender to tough beef occurred between 4.3 and 4.9 kg of WBS based on > or = 86% consumer acceptability. Consumer acceptability for tenderness decreased from 86% at 4.3 kg for a "slightly tender" rating to 59% at 4.9 kg for a "slightly tough" rating. Data from the present study suggested that consumer WBS tenderness values of < 3.0, 3.4, 4.0, 4.3, and > 4.9 kg would result in 100, 99, 94, 86, and 25% customer satisfaction for beef tenderness, respectively. Seventy-eight percent of the consumers would purchase steaks if the retailer guaranteed them to be tender. The retail steak value differences found in this study would result in the opportunity for a premium to be paid for a guaranteed tender (< 3.0 kg WBS value) carcass of $76.26 vs the toughest (> 5.7 kg) classification. A premium of $66.96 could be paid to the tender classification carcasses vs the tough (> 4.9 kg) classification carcasses, and a premium of $36.58 could be paid for the tender classification carcasses vs the intermediate (> 3.0 to < 4.6 kg) classification carcasses. Results from the present study show that consumers can segregate differences in beef tenderness and that consumers are willing to pay more for more-tender beef.


Assuntos
Comportamento do Consumidor , Carne/economia , Carne/normas , Animais , Bovinos , Feminino , Tecnologia de Alimentos/normas , Humanos , Masculino , Distribuição Aleatória , Paladar
7.
Meat Sci ; 54(3): 221-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22060692

RESUMO

Effects of preslaughter rest (0, 1, 2 or 3 h) and hot-fat trimming (HFT, one side) on muscle quality characteristics of hams and loins were tested with 120 pigs. Center-cut loins from each carcass side were vacuum packaged and stored for 7 or 14 days at 2°C. Pigs not rested before slaughter had a skin temperature 3°C higher and ham muscle temperatures 1°C higher than pigs rested 1-3 h (P<0.05). Three hour muscle pH was highest if pigs were rested for 1 h. HFT significantly accelerated carcass chilling rate, but did not affect rate of muscle pH decline. After 14 days of aging, pigs not rested had lower sensory panel ratings for juiciness, tenderness, flavor and overall mouthfeel of loin chops than pigs rested 1 or 2 h. Percentage bound water of hams was highest (P<0.05) if pigs rested 1 or 2 h rather than a shorter or longer times. Pigs should be rested 1 h before slaughter and HFT carried out to allow more rapid carcass chilling and improve muscle quality.

8.
J Anim Sci ; 77(11): 2951-5, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10568463

RESUMO

The objective of this study was to determine effects of electrical stimulation (ES) on muscle quality and sensory traits of 12 Hampshire x Rambouillet callipyge lambs. One side of each carcass was randomly assigned to an ES treatment of 550 V and 60 Hz of electricity for 2 s on and 2 s off 15 times. The other side was a nonstimulated control (NES). Heated calpastatin, sarcomere length, myofibrillar fragmentation index (MFI), Warner-Bratzler shear (WBS), and trained sensory panel values were measured on the semitendinosus (ST), semimembranosus (SM), longissimus (ML), supraspinatus (SP), and triceps brachii (TB) muscles. Electrically stimulating the carcass sides induced a more rapid (P = .001) pH decline in the longissimus muscle, and ES sides had a brighter (P = .001) red color of loineye than nonstimulated sides. At d 14 of storage (2 degrees C), the TB had the highest (P < .05) MFI value, indicating more protein degradation, and the ST and ML muscles had the lowest MFI (P = .008). Regardless of ES treatment, SM and ML had the highest (P < .05) WBS values. The ST muscle had higher (P < .05) WBS values than the SP but did not differ (P > .05) from the TB muscle. Electrical stimulation had no effect on WBS or any trained sensory panel values (P > .05). The percentage of loin chops rated slightly tender or better was improved 30 to 34% by electrical stimulation (P < .05). The ML muscle was scored lower (P < .05) in sustained juiciness compared with the SM, SP, and TB but did not differ (P > .05) from the ST muscle. The SM and ML muscles were rated lower (P < .05) in initial and sustained tenderness scores than other muscles. Tenderness scores were higher (P < .05) for the TB than for the SP but did not differ (P > .05) from the ST muscle. Electrically stimulating callipyge carcasses improves the tenderness of loin chops by increasing the percentage of chops rated from slightly tough to slightly tender.


Assuntos
Carne/normas , Músculos/fisiologia , Característica Quantitativa Herdável , Ovinos/anatomia & histologia , Ovinos/genética , Animais , Cruzamento , Proteínas de Ligação ao Cálcio/metabolismo , Estimulação Elétrica , Concentração de Íons de Hidrogênio , Miofibrilas/ultraestrutura , Fenótipo , Controle de Qualidade , Temperatura
9.
J Anim Sci ; 77(1): 116-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10064034

RESUMO

Beef carcasses (n = 5,542) were evaluated by three USDA on-line graders and compared with the computed expert USDA quality (QG) and yield grades (YG) during 8-h shifts at a major beef-processing facility for a 2-wk period to evaluate the accuracy of applying USDA QG and YG within the traditional five-grade and the proposed seven-grade (segregating YG 2 and 3 into YG 2A, 2B, 3A, and 3B) YG systems. Quality grade distribution of the carcasses was 1.1% Prime, 50.0% Choice, 43.8% Select, and 5.1% No-Roll. Accuracy of applying QG was not affected (P>.05) by changing from the five-grade (91.5%) to either the seven-grade system, when determining only QG (94.3%), or the seven-grade system, when determining QG and YG (95.0%). Calculated expert YG successfully segregated carcasses into their respective YG, but on-line graders could not differentiate between YG 4 and 5 in the seven-grade systems. The application of YG in the five-grade system was more accurate (P<.05) than either of the seven-grade systems. A trend existed for on-line graders to undergrade carcasses as the numerical YG increased. Total accuracy of applying YG decreased by 19.4 to 21.8% when switching from the five-grade to the seven-grade system. The segmentation of USDA YG 2 and 3 into YG 2A, 2B, 3A, and 3B resulted in a decrease in the ability of on-line graders to accurately apply the YG.


Assuntos
Carne/normas , United States Department of Agriculture/normas , Animais , Bovinos , Tecnologia de Alimentos/normas , Controle de Qualidade , Estados Unidos
10.
J Food Prot ; 61(4): 487-9, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9709215

RESUMO

The effects of chilling (normal chill or freeze chill) and trimming (hot fat trim or no fat trim) on the microbial populations of pork carcases were evaluated. In a two-part study, composited ham, loin, belly, and shoulder samples from 30 park carcasses had similar aerobic plate counts, averaging 5.5 log10 CFU/cm2. The nofat trim, normal chill procedure typically used in the industry, however, produced higher coliform and Staphylococcus spp. counts (P < 0.05). The hot fat trim, freeze chill treatment had the lowest lactic acid bacteria counts. Only 1 sample in 60 tested positive for Salmonella spp. Vacuum-packaged hams and loins stored at 4 degrees C for 14 days had similar (P > 0.05) aerobic plate counts, lactic acid bacteria and Staphylococcus spp. counts regardless of trim, chill, or the location of treatment, averaging 5.7, 6.3 and 1.4 log10 CFU/cm2, respectively. Hams had higher counts than loins all three days; however, only the difference on day 2 was significant. The desire to reduce microbial populations on pork carcasses as a food-safety issue and the coming implementation of hazard analysis critical control points (HACCP) programs warrants the use of trimming and chilling methods as critical control points or good manufacturing practices and standard operating procedures in the pork slaughter, processing, and packaging industry.


Assuntos
Matadouros , Manipulação de Alimentos , Suínos/microbiologia , Animais , Temperatura Baixa , Contagem de Colônia Microbiana , Enterobacteriaceae/isolamento & purificação , Lactobacillus/isolamento & purificação , Staphylococcus/isolamento & purificação , Fatores de Tempo
12.
J Anim Sci ; 76(1): 74-86, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9464887

RESUMO

Market pigs (n = 120) were rested 0, 1, 2, or 3 h before slaughter. One carcass side was hot-fat trimmed (HFT) immediately after dressing, and the other was not fat trimmed (NFT). Sides received conventional chilling (CC) or accelerated chilling (AC) in a freezer at -32 degrees C for 100 min. Skin temperatures of live pigs decreased 5 degrees C during 3 h of rest, and resting reduced muscle temperature at .5 and 1.5 h postmortem. Early postmortem muscle pH was .3 higher if pigs were rested up to 2 h if CC was used (P < .01). Resting pigs 2 h decreased loin purge about 1% and increased cured ham yields 6% over those not rested. The AC carcasses had about .15 higher muscle pH from 4.5 to 24 h postmortem than CC carcasses (P < .03). The AC improved loin quality about 15% and lowered L values of loins and hams about 4% (P < .04). The AC substantially reduced the incidence of unacceptable quality in loins and hams, with the most effect on hams, and slightly toughened loin muscles but not cured ham muscles. Resting of pigs and AC of carcasses gave superior color of loin chops at d 0 of retail display and lowered L values during display. The HFT process improved ham quality scores about 8% but not loin scores. Resting pigs for 2 h, AC, and HFT in concert or separately are effective means of improving pork quality; AC had by far the greatest effect.


Assuntos
Temperatura Baixa , Manipulação de Alimentos/métodos , Carne/normas , Animais , Manipulação de Alimentos/normas , Concentração de Íons de Hidrogênio , Controle de Qualidade , Suínos
13.
J Anim Sci ; 75(3): 662-7, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9078481

RESUMO

A boneless beef strip loin (IMPS #180) was fabricated from each of 320 carcasses to study the effects of slaughter plant location, quality grade, fat thickness, and aging time on beef tenderness and palatability. Carcasses were selected for fat thickness (< .5 cm or > or = .5 cm fat thickness) and USDA quality grade (Select or Low Choice) from two slaughter facilities (IBP, Inc., Garden City, KS or Excel Inc., Plainview, TX), and the strips were aged for either 7 or 14 d. Aging steaks 14 d improved all sensory traits and Warner-Bratzler shear (WBS) values regardless of all other main effects (P < .05). Steaks from Choice carcasses that were processed in Kansas had higher initial and sustained tenderness ratings than steaks from carcasses that were processed in Texas or Select steaks from Kansas after 7 d of aging (P < .05). However, aging for 14 d removed differences from all sensory characteristics of steaks from Kansas and Texas. All sensory scores for steaks from carcasses that graded Choice were higher than those from carcasses that graded Select (P < .05). The USDA quality grade did not affect WBS values, and fat thickness did not affect sensory characteristics or WBS values (P > .05). Therefore, aging beef strip loin steaks for 14 compared with 7 d improved sensory score and decreased WBS values, but fat thickness had no effect on the palatability of loin strip steaks processed under these conditions.


Assuntos
Matadouros/normas , Tecnologia de Alimentos/normas , Carne/normas , United States Department of Agriculture , Envelhecimento/fisiologia , Animais , Composição Corporal/fisiologia , Bovinos , Músculo Esquelético/química , Músculo Esquelético/fisiologia , Fatores de Tempo , Estados Unidos
14.
J Anim Sci ; 75(3): 668-72, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9078482

RESUMO

Twenty USDA Standard beef inside rounds were purchased from the Excel Corp. in Plainview, TX to determine the effects of CaCl2 injection and degree of doneness on inside round roasts. Inside rounds were halved and each half served either as a control or was injected with CaCl2. Each half was cut into four sections with one used for retail case display and the other three subjected to cooking at 60, 70, or 80 degrees C doneness. Roasts injected with CaCl2 were more tender as evidenced by higher initial and sustained tenderness scores and lower Warner-Bratzler shear force values (P < .004). Overall beef mouthfeel also was improved over the control by CaCl2 addition (P < .004). Thaw and purge losses were higher (P < .001) for CaCl2-injected roasts and cooking losses were lower (P < .01) than for controls. Injection with CaCl2 did not affect color, color uniformity, discoloration, or surface browning through 1 d of retail case display (P < .05). However, after 2 d of display, control roasts were superior in these traits (P < .05). Roasts cooked to 60 degrees C of doneness were found to be more palatable than those cooked to higher degrees of doneness (P < .05). The improvement in tenderness through CaCl2 injection for tougher cuts from the round is an important finding for the beef industry. The results from this research support the need to use CaCl2 to improve beef tenderness and consistency.


Assuntos
Cloreto de Cálcio/farmacologia , Culinária/métodos , Manipulação de Alimentos/métodos , Tecnologia de Alimentos/métodos , Carne/normas , Animais , Cloreto de Cálcio/administração & dosagem , Bovinos , Manipulação de Alimentos/normas , Tecnologia de Alimentos/normas , Injeções/métodos , Injeções/veterinária , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Temperatura
15.
J Anim Sci ; 75(2): 377-85, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9051460

RESUMO

Effects of CaCl2 injection on meat quality traits of 10 normal and 10 callipyge phenotype crossbred lambs were studied. Primal cuts from one side of each carcass served as the control and cuts from the other side were injected. After storage for 14 d at 2 degrees C, chops were evaluated by Warner-Bratzler shear (WBS) force, trained sensory panel, and consumer sensory panel. Treatment of the muscles with 200 mM CaCl2 increased (P < .05) tenderness and lamb flavor intensity scores by the trained sensory panel and decreased (P < .05) WBS force in both normal and callipyge phenotypes. When callipyge muscles were not injected, consumers rated 94% of leg chops, 60% of loin chops, and 89.4% of shoulder chops acceptable in tenderness. However, when callipyge muscles were CaCl2-injected, consumers rated 96.5% of leg chops, 85.4% of loin chips, and 93.5% of shoulder chops acceptable in tenderness. Normal phenotype carcasses had more marbling (P < .05) in a firmer, finer-textured, brighter cherry red longissimus muscle. Injection of CaCl2 did not affect visual lean color or L, a or b values during retail display of the chops. However, CaCl2 injection decreased color uniformity, increased discoloration, and increased browning at d 2. Therefore, a 5% (wt/wt) injection of 200 mM CaCl2 solution can be applied to improve normal and callipyge lamb tenderness and reduce tenderness and juiciness variation without detrimental effects on other palatability traits when evaluated by trained sensory panelists or consumers.


Assuntos
Cloreto de Cálcio/farmacologia , Tecnologia de Alimentos/métodos , Carne/normas , Ovinos/genética , Animais , Masculino , Músculo Esquelético/efeitos dos fármacos , Fenótipo , Mudanças Depois da Morte , Fatores de Tempo
16.
Nature ; 383(6603): 823-6, 1996 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-8893007

RESUMO

Autoradiography is widely and successfully used to image the distribution of radiolabelled tracer molecules in biological samples. The method is, however, limited in resolution and sensitivity, especially for 14C. Here we describe a new method for imaging 14C-labelled tracers in sections of biological tissue. A highly focused beam of gallium ions bombards the tissue, which is eroded (sputtered) into constituent atoms, molecules and secondary ions. The 14C ions are detected in the secondary beam by the most sensitive method available, namely accelerator mass spectrometry. The specimen is scanned pixel by pixel (1 x 2 microm), generating an image in a manner analogous to scanning electron microscopy. The method can thus be regarded as a specialized form of scanning secondary ion mass spectrometry (SIMS), referred to here as SIAMS (ref. 2). We have used SIAMS to localize the neurotransmitter gamma-aminobutyric acid (GABA) in thin sections of cerebral cortex, and show that it can generate 14C images that are much improved on 14C autoradiography. A scan takes 10-20 min and reveals individual axons, neurons and glial cells at high sensitivity. In principle, the resolution could be increased by up to tenfold, and the method could be extended to some other nuclides.


Assuntos
Radioisótopos de Carbono/análise , Córtex Cerebral/metabolismo , Espectrometria de Massa de Íon Secundário/métodos , Ácido gama-Aminobutírico/análise , Animais , Córtex Cerebral/ultraestrutura , Estudos de Avaliação como Assunto , Gálio , Neurônios/metabolismo , Neurônios/ultraestrutura , Traçadores Radioativos , Ratos , Ratos Wistar
17.
J Anim Sci ; 74(1): 91-7, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8778116

RESUMO

Loin steaks were eaten by 67 consumers over a 15-wk period (n = 739 consumer observations) to determine the consumer acceptability of beef tenderness in the home and a "white table cloth" restaurant. Steaks were rated for tenderness, juiciness, flavor, and overall palatability on an 8-point scale. The acceptability levels for tenderness were established based on Warner-Bratzler shear (WBS) force values, tenderness ratings, and a chisquare analysis of the judgment of tenderness and overall acceptability by the same consumers in both the home and restaurant. Results based only on observations from consumers in Lubbock, TX indicated that the beef industry should target production of beef steaks that have a Warner-Bratzler shear force value of 4.1 kg or less to ensure high levels (98%) of consumer acceptability. Results suggest that an acceptable level of beef tenderness for consumers can be determined and WBS values can be used as criteria for determining which steaks will be considered acceptably tender to consumers before distribution to retail outlets. The beef industry needs to conduct a nationwide research study to determine whether the results from this study will apply to all U.S. beef consumers.


Assuntos
Comportamento do Consumidor , Tecnologia de Alimentos/métodos , Carne/normas , Adolescente , Adulto , Animais , Bovinos , Criança , Feminino , Tecnologia de Alimentos/normas , Indústria de Processamento de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Restaurantes/normas , Estados Unidos
18.
J Anim Sci ; 73(12): 3633-8, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8655438

RESUMO

Beef strip loins from either the right or left side of 22 carcasses of Bos indicus-type steers were injected with 200 mM calcium chloride (CaCl2) solution at 5% (wt/wt) to determine its effect on tenderness and other selected quality traits of steaks. Loins from opposite sides of the carcasses were untreated and served as the control. The steaks were evaluated for tenderness, juiciness, flavor intensity, tenderness acceptability, and overall acceptability by 62 restaurant consumers over a 6-wk period. The CaCl2 injection improved (P < .05) tenderness and flavor intensity ratings by the restaurant consumers. Tenderness acceptability and overall acceptability were improved 23 and 17%, respectively, by the CaCl2 injection. Flavor was not compromised by the CaCl2 injection. The CaCl2-treated steaks were rated superior(P < .05) for flavor compared to the control steaks. Restaurant consumers preferred the beef loin strip steaks injected with 200 mM CaCl2 at 5% (wt/wt). The results of this study are interpreted to indicate that, from a restaurant consumer perspective, CaCl2 injection is an acceptable means of making beef a more consistently tender product.


Assuntos
Cloreto de Cálcio/farmacologia , Comportamento do Consumidor , Tecnologia de Alimentos/métodos , Carne/normas , Músculo Esquelético/efeitos dos fármacos , Adolescente , Adulto , Animais , Bovinos , Feminino , Tecnologia de Alimentos/normas , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Restaurantes
19.
J Anim Sci ; 73(8): 2308-14, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8567467

RESUMO

Beef inside round subprimals were injected with a 200 mM calcium chloride (CaCl2) solution at 5% (wt/wt) to determine its effects on beef steak palatability and quality traits. Alternating subprimals from the right and left sides were selected for injection of CaCl2 or not injected to serve as a control. After 7 d of postmortem storage, 2.5-cm-thick steaks were cut from each subprimal for consumer evaluation (n = 478) in a retail setting. Three supermarkets with customers varying widely in income were selected as test sites for measuring consumer perceptions of the treated and control steaks and package labeling acceptance. Supermarket, income level, education, and sex were evaluated for their impact on acceptance of calcium-injected beef. Steak flavor and tenderness both were important in determining beef eating quality; 50% of consumers said tenderness was the most important and 40% said flavor was the most important. Consumers visually preferred CaCl2-treated steaks 71% of the time over the control steaks based on package labeling. The CaCl2 injection improved tenderness, juiciness, flavor desirability, and overall palatability ratings by the consumers for inside round steaks and did not cause any off-flavor problems compared with the controls. Therefore, injecting beef with a solution of 200 mM CaCl2 at 5% (wt/wt) can improve retail consumer evaluations of beef steak tenderness and reduce tenderness variation without detrimental effects on other palatability or quality traits.


Assuntos
Cloreto de Cálcio , Comportamento do Consumidor , Tecnologia de Alimentos/métodos , Carne/normas , Animais , Cloreto de Cálcio/administração & dosagem , Bovinos , Feminino , Rotulagem de Alimentos , Tecnologia de Alimentos/normas , Indústria de Processamento de Alimentos/economia , Humanos , Masculino , Músculo Esquelético/efeitos dos fármacos , Fatores Socioeconômicos
20.
J Anim Sci ; 73(6): 1735-40, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7673067

RESUMO

Twenty-two Bos indicus type steers were commercially slaughtered, and their carcasses were chilled and processed to determine the effects of injecting calcium chloride (CaCl2) on beef steak palatability and quality traits. Top loin and inside round subprimals were removed from each carcass using industry fabrication procedures. No injection (control) or injection of 200 mM CaCl2 at 5% (wt/wt) was applied at 30 h postmortem to subprimals from alternating right and left sides. After vacuum storage for 7 d postmortem at 2 degrees C, 2.54-cm thick steaks were cut from each subprimal. Eighty-six percent of the control longissimus lumborum (LL) steaks and 78% of the semimembranosus (SM) control steaks had Warner-Bratzler (WBS) values > 4.5 kg, and the injection of CaCl2 reduced this percentage to 43 and 24%, respectively. The injection of CaCl2 improved (P < .05) trained sensory tenderness ratings for both LL and SM, while not affecting (P > .05) flavor intensity or causing any off-flavor problems (P > .05), compared with the controls. Lean color scores for the LL were not affected (P > .05) by the injection of CaCl2, but SM lean color was lighter red (P < .05) than controls. Therefore, a 5% (wt/wt) injection of 200 mM CaCl2 solution can be applied under commercial conditions to improve beef steak tenderness and reduce tenderness variation without detrimental effects on other palatability or quality traits.


Assuntos
Cloreto de Cálcio/farmacologia , Tecnologia de Alimentos/métodos , Carne/normas , Mudanças Depois da Morte , Animais , Cloreto de Cálcio/administração & dosagem , Bovinos , Injeções Intramusculares/veterinária , Masculino , Músculo Esquelético/efeitos dos fármacos , Estações do Ano
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