Chicken breast samples, (n=90; n=30 normal, n=30 moderate woody breast (WB), n=30 severe WB) were collected from a commercial processing plant on 5 separate occasions. After 5 days of storage at 2-4 ºC, 84% of severe WB fillets dissipated to moderate WB, which was greater (P<0.05) than all other storage times. In comparison, 40-52% of the moderate WB fillets dissipated to slight WB or normal breasts after 3 to 5 days of storage. Shear force was greater (P<0.05) for normal breast meat than moderate and severe WB meat on day 0. After 2, 3, 4, and 5 days of storage the upper position (cranial part) of severe WB had greater shear force than normal fillets (P<0.05). Therefore, the dissipation that occurred in woody breast meat over refrigerated storage was apparent through palpation but did not result in improved texture in the cranial portion of the breast, based on shear force results.

No description available.

We have designed and constructed a novel Raman near-field scanning optical microscope (NSOM) and evaluated its performance characteristics with the goal of characterizing the strain in nanoscopic silicon structures. The Raman NSOM was built around a commercial Raman microscope to which a custom built stage was added to provide precise control over the tip position above the sample (z) using shear-force microscopy feedback as well as sample scanning in the x-y plane. The motion control axes were calibrated to better than 1 nm in z and approximately 20 nm in x and y. The NSOM provides both topographical images and Raman mapping with a lateral spectral resolution of 150-300 nm. The experiments described herein were enabled by gold-coated chemically etched NSOM tips with aperture diameters ranging between 60 and 150 nm. The sensitivity of the instrument was demonstrated by the high signal-to-noise ratios observed for Raman scattering by diamond and silicon in reflection mode. Spatial resolution and spectral sensitivity were demonstrated by obtaining well-resolved tip-sample separation curves that provide an accurate estimate of tip aperture size during an experiment. / text

Plantar foot stress causing foot ulceration is a diabetic complication causing major economic burden throughout the world. It has long been thought that shear stresses on the plantar surface of the foot are a major contributing factor to the formation of these ulcers. Although there are many instruments available that measure the vertical foot pressure (vertical forces), there are currently no commercially available instruments to measure the horizontal or shear forces. It is the aim of this project to develop a platform instrument capable of measuring the three dimensional forces (i.e. vertical pressure and shear forces) across the plantar surface of the foot.

This study was conducted to determine threshold levels for Warner-Bratzler shear (WBS) force of the beef value cuts. USDA Choice and USDA Select M. biceps femoris, M. gluteus medius, M. infraspinatus, M. longissimus lumborum, M. rectus femoris, M. triceps brachii, and M. vastus lateralis steaks were evaluated for palatability characteristics and tenderness acceptability by a consumer panel (n = 205). Steaks also were evaluated by WBS analysis. The relationship between consumer tenderness-like ratings and WBS was investigated through regression analysis. Threshold WBS levels could not be determined due to the low correlation between consumer tenderness ratings and WBS. Within a muscle, percent tenderness acceptability was determined for each of the tenderness-like ratings. After analyzing the consumer ratings, tenderness acceptability, and WBS values, it was apparent that there may not be a single WBS threshold value suitable for all muscles. Research indicates that there may be muscle-specific WBS threshold levels; these values were not established from this research.

This research was conducted to investigate the connective tissue contribution to toughness of cow beef and to find means to decrease it. Intra muscular connective tissue (IMCT) content of meat from cows (~6 years) and heifers (~16 months) varied significantly among muscles (P<0.0001) and maturity groups (P<0.05). Amount of total collagen in IMCT was a constant (37.3-46.3 %) among muscles and between maturity groups. Shear force of <i>biceps femoris</i>, <i>semimembranosus</i> and <i>longissimus</i> muscles had increased significantly with animal maturity (P<0.0001). Shear stress of <i>gluteus medius</i> was similar between maturity groups. Collagen solubility decreased with animal maturity, except for <i>biceps femoris</i>. <p> The impact of the temperature of aqueous heating (55 to 95 ºC) and time on thermolabile proteins, amorphous proteins, Ehrlich chromogen, pyridinoline, thickness change, shrinkage, weight gain, shear force, amide bands and morphology of epimysium was studied. Collagen contributed to 90% (w/w) of epimysial proteins. At 55 ºC, epimysial properties were changed only after exposure to long heating times. Shear stress values of raw cow (39.6 N/mm2) and heifer (30.8 N/mm2) epimysium decreased significantly to 11.6 and 2.1 N/mm2, respectively, at 70 ºC. Amount of epimysial amorphous collagen (14-16% w/w) detected after heating at 70 ºC and above was not related to shear stress decrease. Before and after heating, cow epimysium contained more pyridinoline cross-links than heifer epimysium.<p> The effects of strong and weak acids and alkalis on epimysial properties were studied following heating at 55 and 70 ºC for 15 min. As the concentration of HCl (0.1-0.5 M) and pre-equilibration time were increased at 70 ºC, shear stress decreased to <2 N/mm2. Increasing concentration of CH3COOH (0.1-0.5 M) and pre-equilibration times had decreased shear stress to ~5 N/mm2. At 55 ºC, HCl was not superior to CH3COOH in its ability to decrease epimysial shear stress. Increasing concentration of NaOH (0.01-0.05 M) and high temperature decreased shear stress to ~3 N/mm2. Lack of a shear stress decrease at 55 ºC and increased thermal denaturation temperature (66 ºC compared to 63 ºC in water), indicated that NH4OH had an epimysial stabilization effect, which was not eliminated at 55 ºC.

This research was conducted to investigate the connective tissue contribution to toughness of cow beef and to find means to decrease it. Intra muscular connective tissue (IMCT) content of meat from cows (~6 years) and heifers (~16 months) varied significantly among muscles (P<0.0001) and maturity groups (P<0.05). Amount of total collagen in IMCT was a constant (37.3-46.3 %) among muscles and between maturity groups. Shear force of <i>biceps femoris</i>, <i>semimembranosus</i> and <i>longissimus</i> muscles had increased significantly with animal maturity (P<0.0001). Shear stress of <i>gluteus medius</i> was similar between maturity groups. Collagen solubility decreased with animal maturity, except for <i>biceps femoris</i>. <p> The impact of the temperature of aqueous heating (55 to 95 ºC) and time on thermolabile proteins, amorphous proteins, Ehrlich chromogen, pyridinoline, thickness change, shrinkage, weight gain, shear force, amide bands and morphology of epimysium was studied. Collagen contributed to 90% (w/w) of epimysial proteins. At 55 ºC, epimysial properties were changed only after exposure to long heating times. Shear stress values of raw cow (39.6 N/mm2) and heifer (30.8 N/mm2) epimysium decreased significantly to 11.6 and 2.1 N/mm2, respectively, at 70 ºC. Amount of epimysial amorphous collagen (14-16% w/w) detected after heating at 70 ºC and above was not related to shear stress decrease. Before and after heating, cow epimysium contained more pyridinoline cross-links than heifer epimysium.<p> The effects of strong and weak acids and alkalis on epimysial properties were studied following heating at 55 and 70 ºC for 15 min. As the concentration of HCl (0.1-0.5 M) and pre-equilibration time were increased at 70 ºC, shear stress decreased to <2 N/mm2. Increasing concentration of CH3COOH (0.1-0.5 M) and pre-equilibration times had decreased shear stress to ~5 N/mm2. At 55 ºC, HCl was not superior to CH3COOH in its ability to decrease epimysial shear stress. Increasing concentration of NaOH (0.01-0.05 M) and high temperature decreased shear stress to ~3 N/mm2. Lack of a shear stress decrease at 55 ºC and increased thermal denaturation temperature (66 ºC compared to 63 ºC in water), indicated that NH4OH had an epimysial stabilization effect, which was not eliminated at 55 ºC.

This study was conducted to determine threshold levels for Warner-Bratzler shear (WBS) force of the beef value cuts. USDA Choice and USDA Select M. biceps femoris, M. gluteus medius, M. infraspinatus, M. longissimus lumborum, M. rectus femoris, M. triceps brachii, and M. vastus lateralis steaks were evaluated for palatability characteristics and tenderness acceptability by a consumer panel (n = 205). Steaks also were evaluated by WBS analysis. The relationship between consumer tenderness-like ratings and WBS was investigated through regression analysis. Threshold WBS levels could not be determined due to the low correlation between consumer tenderness ratings and WBS. Within a muscle, percent tenderness acceptability was determined for each of the tenderness-like ratings. After analyzing the consumer ratings, tenderness acceptability, and WBS values, it was apparent that there may not be a single WBS threshold value suitable for all muscles. Research indicates that there may be muscle-specific WBS threshold levels; these values were not established from this research.

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-24Bitstream added on 2014-06-13T19:22:52Z : No. of bitstreams: 1 costa_dpb_dr_botfmvz.pdf: 479096 bytes, checksum: 8839d8922f2bb2dde33b43a7d3395c1f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Objetivou-se avaliar o efeito da inclusão de diferentes níveis (0; 14,35; 27,51 e 34,09%) de caroço de algodão na dieta sobre a composição centesimal, maciez, cor e oxidação lipídica da carne de novilhos Nelore. Foram utilizados 36 novilhos não-castrados (peso vivo médio inicial de 333,50 kg e 20 meses de idade), os quais permaneceram por 94 dias confinados em baias com três animais. O delineamento foi o inteiramente casualizado com quatro tratamentos e nove repetições. Não houve diferença entre os tratamentos para o teor de umidade, proteína e cinzas. Entretanto o aumento dos níveis de caroço de algodão reduziu linearmente o percentual de gordura intramuscular. Os valores da força de cisalhamento, oxidação lipídica, cor da carne e cor da gordura foram semelhantes entre os tratamentos. / The objective of this study was to determine the effect of inclusion of whole cottonseed at different levels (0, 14.35, 27.51 and 34.09) in the diet on meat centesimal composition, tenderness, color and lipid oxidation of Nellore steers. Thirtysix steers (average initial body weight of 333.50 kg and aged 20 months) were housed during 94 days in pens with three animals each. A completely randomized design with four treatments and nine replications was used. No difference between treatments was observed concerning moisture, protein and ash contents. However, increasing levels of whole cottonseed caused a reduction in intramuscular fat. The values of shear force, lipid oxidation, meat color and fat color were similar between treatments.

O presente trabalho teve como objetivo estimar a variabilidade genética existente entre touros e linhagens da raça Nelore, essas representadas pelos grandes genearcas, no que se refere à qualidade de carcaça e de carne. Os animais utilizados para coleta de dados de carcaça e carne pertenciam ao projeto de melhoramento genético e de avaliação para emissão de CEIP - Certificado Especial de Identificação e Produção, da Agro-Pecuária CFM-Ltda, e tinham idade entre 21 e 28 meses. Foram analisadas as características peso de carcaça quente (PCQ), área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) e marmoreio (MAR). A qualidade de carne foi avaliada para os períodos de 7, 14 e 21 dias de maturação, quanto às perdas por exsudação (PE), perdas por cozimento (PC) e maciez (MAC). A avaliação da variabilidade genética entre linhagens foi efetuada com base em valores das diferenças esperadas na progênie (DEP) para as características PCQ, AOL, EGS, MAR e MAC aos 7, 14 e 21 dias de maturação. Foi encontrada variabilidade entre os touros e as linhagens estudadas sugerindo que um progresso genético pode ser conseguido pela seleção de animais para características de carcaça e carne dentro da raça Nelore. / The present study had as objective to estimate the genetic variability between steers and breed lines of Nellore, these represented by the greatest breeders, referred to carcass and beef quality. The animals used to collect the samples of carcass and beef belonged to the project of genetic improvement and evaluation to emission of CEIP-Special Certificate of Identification and Production of CFM Farm-Ltda. The animals had age between 21 and 28 months. Were analyzed the characteristics of hot carcass weight (PCQ), rib eye area (AOL), backfat thickness (EGS), marbling (MAR).The beef quality was evaluated for the periods of 7, 14 and 21 days of ageing, as reference the drip loss (PE), cooking loss (PC) and tenderness (MAC). The evaluation of the genetic variability between the breed lines was done based in the values of the expected progeny differences (DEP) of the characteristics of PCQ, AOL, EGS, MAR and MAC at days 7, 14 and 21 of ageing. There was found a variability between steers and the breed lines studied, suggesting that a genetic process may be possible by selecting the animals to carcass and beef characteristics in the Nellore breed.