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1.
Calcif Tissue Int ; 99(4): 408-22, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27272029

RESUMO

The aim of the present study was to study the effect of combined therapy of teriparatide (PTH) or strontium ranelate (SR) with whole-body vibration (WBV) on bone healing and muscle properties in an osteopenic rat model. Seventy-two rats (3 months old) were bilaterally ovariectomized (Ovx), and 12 rats were left intact (Non-Ovx). After 8 weeks, bilateral transverse osteotomy was performed at the tibia metaphysis in all rats. Thereafter, Ovx rats were divided into six groups (n = 12): (1) Ovx-no treatment, (2) Ovx + vibration (Vib), (3) SR, (4) SR + Vib, (5) PTH, and (6) PTH + Vib. PTH (40 µg/kg BW sc. 5×/week) and SR (613 mg/kg BW in food daily) were applied on the day of ovariectomy, vibration treatments 5 days later (vertical, 70 Hz, 0.5 mm, 2×/day for 15 min) for up to 6 weeks. In the WBV + SR group, the callus density, trabecular number, and Alp and Oc gene expression were decreased compared to SR alone. In the WBV + PTH group, the cortical and callus widths, biomechanical properties, Opg gene expression, and Opg/Rankl ratio were increased; the cortical and callus densities were decreased compared to PTH alone. A case of non-bridging was found in both vibrated groups. Vibration alone did not change the bone parameters; PTH possessed a stronger effect than SR therapy. In muscles, combined therapies improved the fiber size of Ovx rats. WBV could be applied alone or in combination with anti-osteoporosis drug therapy to improve muscle tissue. However, in patients with fractures, anti-osteoporosis treatments and the application of vibration could have an adverse effect on bone healing.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Osteoporose/tratamento farmacológico , Teriparatida/administração & dosagem , Tiofenos/administração & dosagem , Vibração/uso terapêutico , Animais , Peso Corporal , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Feminino , Consolidação da Fratura/efeitos dos fármacos , Fraturas Ósseas/tratamento farmacológico , Osteotomia , Ovariectomia , Ratos , Ratos Sprague-Dawley
2.
Poult Sci ; 94(10): 2581-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26316339

RESUMO

Eggs of broilers were initially incubated at 37.8°C, then at 38.8°C (group H) and 36.8°C (group L) between embryonic days 7 to 10 (time A) and days 10 to 13 (time B) and further incubated at 37.8°C until hatching. The chicks were fattened until day 35 and then slaughtered. The effect of treatment, time, and sex and their interactions on carcass and meat quality traits were determined. No significant impact of the "treatment time" was analysed, but "treatment" and "sex" and their interactions influenced (P < 0.05) the different parameters. After hatching, group L broilers were heavier (P < 0.05), followed by slower growth compared to group H chicken. At slaughter day, body, carcass, and leg weights of group H broiler were higher (P < 0.05) and yield results lower (P < 0.05) compared to group L animals. pH, drip loss, shear force, and lightness values of group H broiler breast muscles were higher (P < 0.05) and grill loss and redness values lower (P < 0.05) compared to group L Musculus pectoralis superficialis (MPS). Body, carcass, MPS, and leg weights, leg yields and grill loss and lightness values of the male broiler were higher (P < 0.05) and drip loss results lower (P < 0.05) than the female birds. Male group H broiler showed lower (P < 0.05) carcass and MPS yields compared to the control and group L males, whereas females group H birds had higher (P < 0.05) carcass and MPS weights and lower leg yields (P < 0.05) than the female group L animals. The study shows that an increasing incubation temperature during early embryogenesis positively influences the growth and carcass traits of the broilers, accompanied with a partly negative impact on meat quality (drip loss, shear force, lightness). The growth effects were sex-dependent, as significant weight differences could be only found in female broilers. The results indicate that incubation temperature alteration influences molecular mechanisms in the muscle and other tissues with an impact on growth after hatch.


Assuntos
Galinhas/fisiologia , Carne/análise , Desenvolvimento Muscular , Aumento de Peso , Animais , Peso Corporal , Embrião de Galinha , Galinhas/crescimento & desenvolvimento , Feminino , Masculino , Óvulo , Músculos Peitorais/fisiologia , Temperatura
3.
Asian-Australas J Anim Sci ; 27(4): 551-60, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25049987

RESUMO

Twenty-four male 1-year old swamp buffaloes (Bubalus bubalis) were randomly allocated to 4 groups. One group grazed on guinea grass (GG) and another on guinea grass and the legume Stylosanthes guianensis (GL). The other two groups were kept in pens and fed freshly cut guinea grass and concentrate at an amount of 1.5% (GC1.5) and 2.0% (GC2.0) of body weight, respectively. The effect of the different feeding intensities on carcass characteristics and meat quality were assessed. The mean body weight at slaughter was 398 (±16) kg. Average daily gain was higher in concentrate-supplemented groups (570 and 540 g/d in GC1.5 and GC2.0, respectively) when compared to GG (316 g/d) and GL (354 g/d) (p<0.01). Likewise, the warm carcass weight was higher in GC1.5 and GC2.0 compared to GG and GL. Dressing percentage was 48.1% and 49.5% in GC1.5 and GC2.0 in comparison to 42.9% and 44.8% observed in GG and GL, respectively. Meat of Longissimus throracis from GC1.5 and GC2.0 was redder in color (p<0.01), while water holding capacity (drip and thawing loss) was improved in pasture-fed groups (p<0.05). Protein and fat content of Longissimus thoracis was higher in animals supplemented with concentrate (p<0.01), as was cholesterol content (p<0.05), whereas PUFA:SFA ratio was higher and n-6/n-3 ratio lower (p<0.01) in pasture-fed buffaloes. Results of the present study showed that the supplementation of pasture with concentrate enhances the growth and carcass characteristics of swamp buffaloes expressed in superior dressing percentage, better muscling, and redder meat with a higher content of protein and fat, whereas animals grazing only on pasture had a more favorable fatty acid profile and water holding capacity. In conclusion, the supplementation of concentrate at a rate of about 1.5% of body weight is recommended to improve the performance and carcass quality of buffaloes.

4.
Poult Sci ; 92(5): 1366-75, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23571348

RESUMO

It has been suggested that the color of turkey breast meat influences both physico-chemical and microbiological properties of raw fermented sausages. In this study, raw fermented sausages were produced with turkey breast meat in 3 different colors (pale, normal, or dark), which were obtained from 2 fast-growing-genetic-line toms at 2 slaughterhouses. Prior to the sausage production, the breast muscles were sorted into color groups according to the lightness values determined at 24 h postmortem. This meat was subsequently processed to raw fermented sausages using 1.5 or 2.5% curing salt (CS). The pale meat had higher lightness, electrical conductivity, and drip loss, whereas the dark meat showed a darker color only. The physico-chemical (pH, water activity), visual (lightness, redness), and microbial (total plate count) properties of the sausages were not influenced by the color of the turkey breast meat. The sausage made with 2.5% CS had lower aw and higher ash and hardness values than the sausages produced with 1.5% CS. In conclusion, processing of differently colored turkey meat to raw fermented sausages does not influence the quality characteristics of the products. Based on these findings, there is no reason for the sausage producer to separate turkey breast muscles by color before producing raw fermented sausages.


Assuntos
Produtos da Carne/microbiologia , Produtos da Carne/normas , Músculos Peitorais/fisiologia , Pigmentação , Perus/fisiologia , Animais , Contagem de Colônia Microbiana , Fermentação , Masculino , Músculos Peitorais/química
5.
Br Poult Sci ; 54(1): 5-11, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23444849

RESUMO

1. The study investigated the influence of manipulating incubation temperature for a short period on the post-hatch development up to week 16 in male and female BUT Big 6 turkeys. 2. Eggs were incubated at a control temperature of 37·5°C and 55% RH until d 18 when transferred to a hatcher at 37·5°C and 85% RH. For a 4 d period between embryonic day 9 (ED 9) and 12, eggs were incubated at 38·5°C and 55% RH (HT). 3. Birds were slaughtered at 16 weeks of age to analyse meat quality parameters of the Musculus pectoralis superficialis (MPS). 4. Across both incubation treatments, the turkey males had significantly higher live and breast weights, but lower breast yields than the females. The sex of the animals only influenced the yellowness of the MPS with lower values in the males. 5. Temperature manipulation resulted in significantly decreased live weights of HT birds compared with the control animals across all ages in both sexes. No impact of incubation treatment on meat quality characteristics was found. 6. The results indicate a negative effect of higher incubation temperature on the post-hatch growth, possibly by influencing the mechanisms that regulate the hypertrophic growth of the muscle fibres.


Assuntos
Desenvolvimento Embrionário , Carne , Temperatura , Perus/embriologia , Criação de Animais Domésticos/métodos , Animais , Peso Corporal , Feminino , Masculino , Perus/anatomia & histologia , Perus/crescimento & desenvolvimento
6.
Poult Sci ; 90(8): 1774-81, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21753215

RESUMO

Broilers from the lines Ross 308, Ross 708, and Cobb 700 were slaughtered at 28 and 41 d of age at a commercial abattoir. After slaughter, the carcass, breast, and leg weights as well as the breast and leg yields were determined. Further investigations analyzed the color [lightness (L*), redness (a*), and yellowness (b*)], pH at 24 h postmortem, electrical conductivity (EC), drip loss, grill loss, and shear force values as well as the muscle fiber cross-sectional areas of the breast muscles. The 41-d-old broilers had higher carcass, breast, and leg weights than the 28-d-old birds. The breast yield values were higher and the leg yields were lower in the 41-d-old broilers. The fiber cross-sectional area values were also higher in the older birds. Within the younger birds the slaughter characteristics were approximately comparable among the lines. The EC, L*, grill loss, and shear force values increased but the drip loss and a* values decreased with the age of the broiler. The genetic lines differed within the 28-d-old broilers with regard to EC, grill loss, and shear force values and within the 41-d-old broilers with regard to the EC, L*, grill loss, and shear force values. The pH correlated negatively with the EC, L*, b*, drip loss, and shear force values. During storage, L* and b* values of the breast muscles increased and a* values decreased in all genetic lines, whereas the L* values were generally higher in the older broilers and the a* and b* results were generally higher in the breast muscles of the younger broilers. In conclusion, the carcass and meat quality characteristics of broilers changed with age with positive (carcass and breast muscle weight, drip loss) but also negative (L*, a*, grill loss) effects. The effect of the genetic line was rather low. Despite the age-related changes of meat quality parameter, the pH values remained unchanged, indicating muscle structural influences on the muscle-to-meat-transition with increasing age of the broiler.


Assuntos
Envelhecimento/fisiologia , Carne/normas , Músculo Esquelético/fisiologia , Animais , Galinhas/genética , Galinhas/fisiologia , Fatores de Tempo
7.
Meat Sci ; 81(1): 155-62, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22063976

RESUMO

Carcass and meat quality of Thai native cattle, fattened for 2 years on Guinea grass (Panicum maxima) and Guinea grass-legume (Stylosanthes guianensis) pastures, were investigated in twelve 3-years old males. Groups had similar carcass quality except for kidney fat percentage (higher in cattle of the grass-legume group). This group also had a lighter meat (Longissimus dorsi, Infraspinatus) than the grass-only fed cattle. Shear force was generally at the borderline to tender meat, and was unaffected by treatment as were other texture-related properties except muscle fibre diameter. Meat of the grass-legume group was perceived less juicy (P<0.05) but more tender (P<0.1). The meat of the grass-legume-fed cattle also had more intramuscular fat (4.3% vs. 3.4%) and a slightly less favourable n-6:n-3 fatty acid ratio (2.2 vs. 2.0). In conclusion, the mostly weak differences in carcass and meat quality did not clearly favour one of the grazing systems.

8.
Br Poult Sci ; 50(3): 318-24, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19637031

RESUMO

1. An experiment was conducted to compare different meat quality parameters, especially colour development, in the breast muscle of turkeys and broilers. 2. A total of 160 broilers (Ross 308) with a mean age of 32 d and 120 turkeys (BUT Big 6) with a mean age of 147 d were slaughtered at 4 (broilers) or three (turkeys) dates at two commercial abattoirs and the slaughter characteristics (slaughter and breast weight, breast yield) were determined. 3. The Musculus pectoralis superficialis (MPS) was collected and different meat quality parameters (pH, electrical conductivity (EC), colour (L * a * b*), grill loss, shear force) were analysed 24 h after slaughter; the colour development during cold storage of the MPS was also analysed. 4. The turkeys had greater carcase and breast weights as well as breast yields. The pH was significantly lower and the EC as well as the grill loss significantly higher in the MPS of the turkey, whereas the shear force values were comparable. 5. Considering the colour of the breast muscle the broiler MPS had significantly higher L* and b* but lower a* values. During cold storage the L* and b* values of the MPS increase in both investigated poultry species, whereas a* increased in the turkey but decreased in the broiler birds. The L* and b* of the broiler and turkey MPS thereby increased in parallel. 6. From the results of this and previously published studies that investigated only broilers or turkeys it can be concluded that chemical (or biochemical) differences between these poultry species exist that specifically influence the muscle-to-meat transition process after slaughter.


Assuntos
Carne/normas , Músculo Esquelético/química , Animais , Galinhas , Cor , Culinária , Concentração de Íons de Hidrogênio , Masculino , Perus
9.
Poult Sci ; 87(9): 1849-59, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18753454

RESUMO

The increase in human consumption of turkey meat and the shift in the poultry market from whole birds to further processed meat products increases the visibility of meat alterations (e.g., heterogenic color, drip loss, petechial hemorrhages) at retail. Changes in poultry meat quality have been related to the intensive growth of the current turkey strains. Considering this, the main objective of this investigation was to evaluate the meat quality and muscle structure of commercially available turkey strains with different growth properties but similar breast yields. Toms (n = 120) of 4 different turkey strains (British United Turkeys Big 6, Kelly Broad-Breasted Bronze, Kelly Wrolstad, Kelly Super Mini; n = 30 per strain) were reared in an experimental barn under similar environmental and feeding conditions and were slaughtered at 22 wk of age in a commercial slaughterhouse. The strains Big 6 and Broad-Breasted Bronze belong to the fast-growing (FG) turkey strain and the other 2 to the slow-growing (SG) turkey strain. The carcass weights, as estimated by video imaging, differed significantly (P < 0.05) between the SG and FG groups. The breast yields (percentage of carcass weight) of the investigated strains were similar. Except for the significantly (P < 0.05) greater protein concentration in the musculus pectoralis superficialis of the SG birds, the musculus pectoralis superficialis had nearly similar fat and ash contents. Plasma lactate concentrations were similar in the investigated turkey strains but the creatine kinase activities were greater in the FG turkeys at the time of slaughter. Determination of the different meat quality parameters [pH, electrical conductivity, color (L a b), drip loss, shear force] did not result in clear differences between the SG and FG turkey strains. There were larger muscle fibers in the FG in comparison with the SG strains, but no differences could be determined in the capillary density and incidence of degenerated or giant fibers, except for a higher rate in the Wrolstad strain. The present results are contradictory to the opinion that turkeys with faster growth have worse meat quality.


Assuntos
Composição Corporal/genética , Composição Corporal/fisiologia , Músculo Esquelético/fisiologia , Perus/genética , Perus/fisiologia , Matadouros , Animais , Peso Corporal , Creatina Quinase/sangue , Ácido Láctico/sangue , Carne
10.
Poult Sci ; 87(1): 160-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18079466

RESUMO

This study examined the effects of 4 genotypes of chicken, all suitable for extensive fattening, on carcass and meat quality using 320 chickens divided into 4 equally sized groups. The comparison included 2 indigenous chicken strains from Thailand, Black-boned and Thai native (Thai), and 2 imported chicken breeds, Bresse and Rhode Island Red (Rhode, a layer breed). The animals were fed until 16 wk of age. Breast (pectoralis major) and thigh (biceps femoris) muscles were studied in detail. Chickens of the imported breeds were heavier at slaughter than indigenous strains, especially Black-boned chickens. Proportions of retail cuts with bones were similar among genotypes, whereas deboned breast meat and lean:bone ratio were lowest in the layer breed (Rhode). The meat of the Black-boned chickens was darker than that of the other genotypes. Thai and Rhode chickens had a particularly yellow skin. The ratio of red and intermediate to white fibers was higher in the thigh muscle, and the diameter of all muscle fiber types in both muscles was smaller in the indigenous compared with the imported breeds. The meat of the 2 indigenous Thai strains had lower contents of fat and cholesterol compared with that of the imported breeds, especially relative to the Rhode chickens (thigh meat). The meat of the indigenous origins, especially of the Thai chickens, was higher in shear force and collagen content (thigh only) than meat of the imported breeds. The meat lipids of the Thai chickens had particularly high proportions of n-3 fatty acids and a favorably low n-6/n-3 fatty acid ratio compared with the other genotypes. In conclusion, meat of indigenous chickens has some unique features and seems to have more advantages over imported breeds than disadvantages, especially when determined for a niche market serving consumers who prefer chewy, low-fat chicken meat.


Assuntos
Galinhas , Carne , Animais , Peso Corporal , Galinhas/genética , Colesterol/análise , Colágeno/análise , Ácidos Graxos não Esterificados/análise , Genótipo , Histocitoquímica/veterinária , Análise dos Mínimos Quadrados , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Músculos Peitorais/metabolismo , Distribuição Aleatória , Resistência ao Cisalhamento , Tailândia , Triglicerídeos/análise
11.
Animal ; 12(6): 1224-1231, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29070090

RESUMO

Broiler eggs were either incubated at 37.8°C during the whole incubation period (control), or at higher (38.8°C, group H) and lower temperatures (36.8°C, group L) from embryonic day (ED) 7 up to ED 10 (ED 7 to 10) or from ED 10 up to ED 13 (ED 10 to 13). Before and after this temperature treatment the eggs were incubated at 37.8°C. The day-old chicks were weighted, sexed and fed up to day 35. On days 1 and 35 samples were taken from the breast and leg muscles for analyzing of the mitochondrial respiratory activity (MRA) and from the breast muscles for analysis of the cross-sectional areas (CSA) and the glycogen phosphorylase (GP), phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS) and cytochrome oxidase (COX) activities. Statistical analysis showed that treatment (control, group H, group L), sex and their interaction, but not the treatment period (ED 7 to 10; ED 10 to 13), significantly influenced the results. Group H chicks had lower (P⩽0.05) body and heart weights but higher (P⩽0.05) liver weights, CSA values, leg MRA as well as PFK, LDH, CS, GP and COX activities compared with the group L chicks. The results of the control chicks differ (P⩽0.05) from those of the group H (body, heart weight, COX), the group L chicks (liver weight, PFK, LDH, CS, GP) or the birds of both other groups (CSA). The group H broiler had higher (P⩽0.05) body and leg weights as well as LDH, CS, COX and GP activities than the group L broilers. The BWs and the LDH and GP results of the control broiler differ (P⩽0.05) from those of both other groups or from the results of the group H (CS) and group L broiler (COX). Female broilers had lower (P⩽0.05) body, breast and leg weights, but higher (P⩽0.05) CSA, LDH, CS and GP activities than the male animals. Analysis of treatment×sex interaction showed that group H hens had higher (P⩽0.05) body and breast weights, LDH and GP activities compared with the group L hens, whereas in the male broiler no effect of the interaction could be found, except for the lower (P⩽0.05) CSA values in the group H than group L cocks. The treatment effects are probably due to altered embryonic activity and related molecular mechanisms. The sex-related differences in the broiler indicate that these alterations already occur in the embryos and chicks, but become significant with the sexual dimorphism after hatch.


Assuntos
Galinhas , Desenvolvimento Embrionário , Músculos Peitorais , Temperatura , Animais , Embrião de Galinha/crescimento & desenvolvimento , Galinhas/crescimento & desenvolvimento , Feminino , Masculino , Óvulo , Músculos Peitorais/crescimento & desenvolvimento
12.
Meat Sci ; 72(3): 545-54, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22061739

RESUMO

In the present study German (DE), Spanish (ES) and British (UK) consumers' acceptance of lamb from their own country compared to lamb from Uruguay (UY) was evaluated. Two-hundred consumers in each country evaluated tenderness, flavour and overall acceptability of four types of lamb, two from UY (light and heavy lambs aged 20 d) and 2 local (with two ageing times, 7 and 20 d). In each country 1.5cm-thick slices of lamb were evaluated by previously selected consumers in controlled conditions. DE and UK consumers showed significantly (P<0.05) different acceptability scores between samples, the lamb from heavier animals and aged 20 d being the most appreciated. On the other hand the majority of the ES consumers significantly (P<0.05) preferred the meat from lighter lambs. Production systems, cultural aspects and consumption habits seem to affect the acceptability of the lamb to the consumers.

13.
Meat Sci ; 74(3): 435-42, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22063047

RESUMO

The acceptability of beef from Uruguay (UY), based on eating quality, was compared with beef produced in different European countries (Germany, DE, Spain, ES and United Kingdom, UK). Consumer tests were conducted in DE, ES and UK (each comprising 200 consumers) using 'Hall Tests'. In each country four samples were evaluated, two from Hereford steers from UY (finished at 2 and 3 years) and two from local meat (the same meat sample aged 7 or 20d). Consumers evaluated tenderness, flavour and overall acceptability using 8-point category scales. Hierarchical cluster analysis, highlighted the existence of different clusters of consumers. Two main clusters were identified in DE and UK. The main cluster identified in DE, was labelled as Prefer foreign-imported beef (n=128). These consumers preferred (P<0.05) the samples from UY_2y in terms of tenderness and overall acceptability. The other cluster was labelled as Prefer local beef in terms of flavour and overall acceptability (P<0.05) and comprised the majority of consumers from ES (n=176) and UK (n=153) and the cluster 2 from DE (n=69). UK, cluster 2 (n=33) that did not discriminate between origin and ageing time of beef. These results indicate that consumers did not prefer the same type of meat within the same country and it is possible that there are individual preferences that could lead to the concept of market segmentation being based on taste preferences. It would appear that Uruguayan beef would be very acceptable in Germany and to a lesser extent in Britain and Spain, although further studies are required that include labelling information.

14.
J Nutr Metab ; 2016: 3703216, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28050282

RESUMO

Sarcopenia, a loss of muscle mass accompanying osteoporosis, leads to falls and fall-related injuries. Baicalein, as a phytochemical agent, has an antioxidative and anti-inflammatory effect in muscle. In this study, sixty-one female Sprague Dawley rats were divided into five groups: four groups were ovariectomized (OVX) and one control group was nonovariectomized (NON-OVX). Eight weeks after ovariectomy, three disparate concentrations (1 mg/kg body weight (BW), 10 mg/kg BW, and 100 mg/kg BW) of baicalein were applied subcutaneously daily in three OVX groups. Mm. soleus, gastrocnemius, and longissimus were extracted; their diameter, area, relation to body, and muscle weights as well as number of capillaries per fibre were recorded. In Mm. soleus and gastrocnemius, the baicalein effect (increasing number of capillaries per fibre) was proportional to the dose applied. The fibre diameters and area under baicalein treatment were significantly greater compared to OVX and NON-OVX groups. In M. longissimus, we observed a shift to type IIa fibres. Serum creatine kinase levels were significantly lower in highest baicalein concentration group. We conclude that baicalein can stimulate angiogenesis, though not fibre type-specific, in skeletal muscle and reduce the estrogen-related loss of fibre diameter and area in the skeletal muscle in rats. Therefore, a protective effect of baicalein on muscle cells can be assumed.

15.
J Mol Biol ; 300(4): 935-50, 2000 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-10891279

RESUMO

Coenzyme F(420)-dependent methylenetetrahydromethanopterin reductase (Mer) is an enzyme of the Cl metabolism in methanogenic and sulfate reducing archaea. It is composed of identical 35-40 kDa subunits and lacks a prosthetic group. The crystal structure of Mer from Methanopyrus kandleri (kMer) revealed in one crystal form a dimeric and in another a tetrameric oligomerisation state and that from Methanobacterium thermoautotrophicum (tMer) a dimeric state. Each monomer is primarily composed of a TIM-barrel fold enlarged by three insertion regions. Insertion regions 1 and 2 contribute to intersubunit interactions. Insertion regions 2 and 3 together with the C-terminal end of the TIM-barrel core form a cleft where the binding sites of coenzyme F(420) and methylene-tetrahydromethanopterin are postulated. Close to the coenzyme F(420)-binding site lies a rarely observed non-prolyl cis-peptide bond. It is surprising that Mer is structurally most similar to a bacterial FMN-dependent luciferase which contains a non-prolyl cis-peptide bond at the equivalent position. The structure of Mer is also related to that of NADP-dependent FAD-harbouring methylenetetrahydrofolate reductase (MetF). However, Mer and MetF do not show sequence similarities although they bind related substrates and catalyze an analogous reaction.


Assuntos
Euryarchaeota/enzimologia , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Riboflavina/análogos & derivados , Riboflavina/metabolismo , Adaptação Fisiológica , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Meio Ambiente , Flavina-Adenina Dinucleotídeo/química , Flavina-Adenina Dinucleotídeo/metabolismo , Flavinas/química , Flavinas/metabolismo , Methanobacterium/enzimologia , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Riboflavina/química , Alinhamento de Sequência
16.
Meat Sci ; 69(2): 187-99, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22062808

RESUMO

The eating quality of porcine meat is supposed to increase with increasing intramuscular fat content (IMF). The aim of this study was to investigate the use of acoustic parameters obtained by spectral analysis of ultrasound echo signals to non-destructively predict intramuscular fat content of porcine longissimus muscle. Ultrasound is regarded as a promising non-destructive technique to characterize tissue. Ultrasound data acquisition was performed at slaughter with a clinical B-mode device equipped with a 3.5 MHz center-frequency transducer on 115 warm carcasses about 45 min postmortem. Acoustic parameters quantifying attenuation, backscattering and cepstral structure were calculated off-line from the recorded primary raw ultrasound echo signals. Their relationship to IMF content was investigated. IMF level significantly influenced powerspectrum amplitudes and backscatter parameters. With partial least-squares regression (PLS), the IMF content could be predicted with root mean standard error of prediction RMSEP of 0.36% IMF. The ultrasound parameters were able to correctly classify nearly 80% of the carcasses into HIGH and LOW level class, respectively. Results indicate the potential use of ultrasound spectral analysis for non-destructive evaluation (NDE) of pig carcasses in order to estimate the IMF content.

17.
Animal ; 9(2): 356-61, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25245462

RESUMO

The way the pH falls post-slaughter has an impact on meat quality. Pork longissimus muscles (n=48) were sorted in fast- (FG) (n=15) and normal glycolysing (NG) (n=33) muscles according to the post-slaughter pH 45 min values (FG<6.0; NG>6.0). FG muscles (5.84±0.04) compared with NG muscles (6.27±0.04) were accompanied with higher temperature, electrical conductivity, lightness and yellowness, and reduced grill loss and shear force values (P<0.05), but there were no pH-dependent changes of the drip loss and redness results. FG muscles had higher (P<0.05) percentages of fast-twitch glycolytic and lower proportions of fast-twitch oxidative and slow-twitch oxidative (P<0.05) muscle fibres. The study confirms the relationship of pH value to meat quality and muscle fibre characteristics also showing that pH values have no impact on intrinsic mitochondrial respiratory function.


Assuntos
Carne/normas , Músculo Esquelético/fisiologia , Suínos/fisiologia , Animais , Glicólise , Temperatura Alta , Concentração de Íons de Hidrogênio , Mitocôndrias/metabolismo , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/química , Oxirredução , Consumo de Oxigênio
18.
Meat Sci ; 53(1): 9-15, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22062927

RESUMO

In pigs, intensive growth of the musculature is often accompanied by malignant hyperthermia susceptibility (MHS; n gene) and poorer meat quality. Using histological and histochemical methods, different fibre characteristics in the Longissimus muscle were found in Pietrain×German Landrace pigs with this gene defect. Compared to MHS homozygous negative pigs, groups with the n gene had increased diameters of the mean fibre types and increased glycolytic metabolic potential, as shown by a higher frequency of the fast twitch glycolytic type and a lower frequency of the slow twitch oxidative fibre type. Differences between the groups were also found in the number of angular and giant fibre types. Furthermore, a positive correlation was found between the frequency of oxidative fibres and the relative enzyme activity of NADH tetrazolium reductase. The changes correlated with lower pH and higher drip loss in meat from the MHS homozygous positive group. In conclusion, the different muscle fibre characteristics can be interpreted as endogenous factors which influence the physiological condition in the muscle of the live animal and meat quality post mortem.

19.
Meat Sci ; 96(4): 1440-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24398003

RESUMO

This study investigated whether the positive effects of ageing on tenderness of meat from culled dairy cows can be facilitated by CaCl2. Injections of 250 mM CaCl2 solution (10% wt/wt) were performed on Longissimus dorsi samples from 32 7-yrs old cows. Samples were vacuum packaged and aged for 0, 1, 3, 5 and 7 days. Ageing alone produced lighter and less red meat with lower shear force, higher myofibrillar fragmentation and tenderness scores but also elevated lipid oxidation. For most traits investigated, CaCl2-injected meat exhibited similar ageing effects, but drip loss increased with age. The CaCl2-injected meat had a lower shear force and myofibrillar fragmentation increased more rapidly, but drip loss, off-flavour scores, colour stability and oxidative stability were inferior to untreated meat. Overall, it was found possible to accelerate tenderisation of such meat with CaCl2, but only at the cost of adverse effects in some other quality traits.


Assuntos
Cloreto de Cálcio , Peroxidação de Lipídeos , Carne/análise , Estresse Mecânico , Paladar , Animais , Bovinos , Cor , Indústria de Laticínios , Feminino , Manipulação de Alimentos , Humanos , Carne/normas , Músculo Esquelético , Miofibrilas , Água
20.
Meat Sci ; 94(4): 468-73, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23624436

RESUMO

This study investigated the impact of two information conditions and two androstenone concentrations on the acceptability of fermented sausages made from boar meat. Two batches of salamis were produced by mixing bellies and lean meat resulting in average androstenone levels of 0.408 µg/g vs. 1.585 µg/g melted fat, respectively. Skatole levels were kept below 0.05 µg/g melted fat in the final products. The consumers were provided with either the information that the products consisted of 100% pork or 100% boar meat. In total, 478 visitors of an animal husbandry fair, assumed to be familiar with the consequences of not castrating male piglets, evaluated the salami following a monadic between-subject design. The information did not significantly affect the hedonic scores. The percentage of dislikes was very low, i.e. 3 vs. 6% (p=0.24) for salami LOW and HIGH, respectively. The batch with lower androstenone content was liked slightly but significantly better (p=0.03).


Assuntos
Comportamento do Consumidor , Rotulagem de Alimentos , Produtos da Carne , Escatol , Paladar , Adolescente , Adulto , Criação de Animais Domésticos , Animais , Dieta , Gorduras na Dieta , Feminino , Fermentação , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Prazer , Suínos , Adulto Jovem
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