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José Angel Pérez-alvarez - One of the best experts on this subject based on the ideXlab platform.
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Quality characteristics of Ostrich (Struthio camelus) burgers
Meat science, 2006Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, Esther Sendra, S. Jiménez, José Angel Pérez-alvarezAbstract:Quality characteristics and storage stability of three types of burgers prepared with Ostrich meat (alone or mixed with pork or beef meat) were evaluated. Burger evaluation was based on chemical, microbiological, textural, colour, sensory and oxidation characteristics. All of the assayed formulas showed acceptable general quality scores in the sensory evaluation, but the burgers formulated with 100% Ostrich meat or mixing Ostrich and beef meat had the highest scores. Only TBA values and redness were influenced by storage time. Burgers formulated with Ostrich and pork meat had a faster oxidation rate and became more oxidized than the others. Microbial counts indicated that, at the end of the refrigerated storage (9 days), all of the preparations were spoiled.
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Physical, Chemical, and Sensory Properties of Bologna Sausage Made with Ostrich Meat
Journal of Food Science, 2003Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, C. Navarro, Esther Sendra, José Angel Pérez-alvarezAbstract:: Three formulations of bologna were prepared, differing only by the lean meat used: (1) Ostrich meat from Iliofibularis muscle (fan thigh), (2) Ostrich meat from Femorotibialis medius muscle (tip thigh), and (3) beef meat from Subscapularis muscle (shoulder). Physical, chemical, and sensory analyses were made. The final products formulated with Ostrich meat, although having a dark appearance, were acceptable in chemical composition and other sensory characteristics. The low fat and high protein content for Ostrich bolognas will help to ensure that, if marketed in sufficient quantities, Ostrich meat can successfully compete with other healthy meat products. The Ostrich meat (Iliofibularis muscle) formula reached the highest general quality scores in the sensory evaluation.
Juana Fernández-lópez - One of the best experts on this subject based on the ideXlab platform.
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Quality characteristics of Ostrich (Struthio camelus) burgers
Meat science, 2006Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, Esther Sendra, S. Jiménez, José Angel Pérez-alvarezAbstract:Quality characteristics and storage stability of three types of burgers prepared with Ostrich meat (alone or mixed with pork or beef meat) were evaluated. Burger evaluation was based on chemical, microbiological, textural, colour, sensory and oxidation characteristics. All of the assayed formulas showed acceptable general quality scores in the sensory evaluation, but the burgers formulated with 100% Ostrich meat or mixing Ostrich and beef meat had the highest scores. Only TBA values and redness were influenced by storage time. Burgers formulated with Ostrich and pork meat had a faster oxidation rate and became more oxidized than the others. Microbial counts indicated that, at the end of the refrigerated storage (9 days), all of the preparations were spoiled.
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Physical, Chemical, and Sensory Properties of Bologna Sausage Made with Ostrich Meat
Journal of Food Science, 2003Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, C. Navarro, Esther Sendra, José Angel Pérez-alvarezAbstract:: Three formulations of bologna were prepared, differing only by the lean meat used: (1) Ostrich meat from Iliofibularis muscle (fan thigh), (2) Ostrich meat from Femorotibialis medius muscle (tip thigh), and (3) beef meat from Subscapularis muscle (shoulder). Physical, chemical, and sensory analyses were made. The final products formulated with Ostrich meat, although having a dark appearance, were acceptable in chemical composition and other sensory characteristics. The low fat and high protein content for Ostrich bolognas will help to ensure that, if marketed in sufficient quantities, Ostrich meat can successfully compete with other healthy meat products. The Ostrich meat (Iliofibularis muscle) formula reached the highest general quality scores in the sensory evaluation.
Willem Oelofsen - One of the best experts on this subject based on the ideXlab platform.
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Purification and primary structure of Ostrich pancreatic polypeptide
International Journal of Peptide and Protein Research, 2009Co-Authors: Derek Litthauer, Willem OelofsenAbstract:: Pancreatic polypeptide has been isolated from Ostrich pancreas by gel filtration, ion exchange chromatography and high pressure liquid chromatography. The Ostrich peptide contains 36 amino acids and has an amino acid composition similar to pancreatic polypeptide of other avian species. The primary structure of Ostrich pancreatic polypeptide differs from that of the chicken peptide only at residues 3 and 18 where the Ostrich peptide contains an alanine and a valine residue compared to the serine and isoleucine residues found in those positions in the chicken peptide.
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Ostrich PEPSINS I AND II : A KINETIC AND THERMODYNAMIC INVESTIGATION
The International Journal of Biochemistry & Cell Biology, 1995Co-Authors: Brett I. Pletschke, Ryno J. Naudé, Willem OelofsenAbstract:Two forms of Ostrich pepsin have been purified, Ostrich pepsins I and II. The aim of this study was to characterize these pepsins in terms of temperature and alkaline stability, temperature and pH optima, and to investigate their kinetic properties. The effect of pH and temperature on Ostrich pepsins was studied using the haemoglobin assay method. The hydrolysis of a synthetic hexapeptide substrate Leu-Ser-Phe-(NO 2 )-Nle-Ala-Leu-OMe was followed spectrophotometrically at 310 nm. The activity of pepsins towards short synthetic substrates were investigated using ninhydrin. Inhibition studies were performed with the reversible inhibitor pepstatin A and the inhibitors DAN, EPNP and p -bromophenacyl bromide. Ostrich pepsins exhibited an optimum pH of 2.0 towards haemoglobin, and were stable up to pH 7. 5. The optimum temperature for Ostrich pepsin II was at 60°C, while Ostrich pepsin I showed a broader optimum temperature range (40–60°C). Ostrich pepsin I was more susceptible to heat inactivation than Ostrich pepsin II. Both pepsins showed a lower activity towards haemoglobin than porcine pepsin. Only Ostrich pepsin II could hydrolyse the hexapeptide substrate, albeit at a much slower rate than porcine pepsin. The activity of the Ostrich pepsins towards short synthetic peptides was generally very low. Pepstatin A is a very potent inhibitor of Ostrich pepsins with a K i of 2.14–2.2 × 10 −8 M. EPNP, DAN and p -bromophenacyl bromide were all inhibitory to Ostrich pepsin II, DAN requiring the presence of Cu 2+ . Ostrich pepsins exhibited similar thermal and kinetic properties when compared to pepsins of avian origin. Avian pepsins are generally more stable to alkaline conditions, and exhibit low activity towards short synthetic substrates.
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Ostrich pepsinogens i and ii purification activation and chemical and immunochemical characterization of the enzymes from the proventriculus
The International Journal of Biochemistry & Cell Biology, 1995Co-Authors: Brett I. Pletschke, Ryno J. Naudé, Willem Oelofsen, Koji Muramoto, Fumio YamauchiAbstract:Pepsins are a series of gastric proteases secreted as inactive precursors (pepsinogens) which are active at acidic pH. The aim of this study was to purify Ostrich pepsin(ogen)s and to compare their biochemical and immunological characteristics with those of pepsin(ogen)s of mammalian and avian origin. Ostrich pepsinogens were purified by ammonium sulphate fractionation, Toyopearl Super Q-650S chromatography and rechromatography, and hydroxylapatite chromatography of a pH 8.0 mucosal extract. Pepsins were obtained through acidification, and purified by chromatography on SP-Sephadex C-50. Amino acid compositions, N-terminal sequences, Ouchterlony double-diffusion as well as Western blot analysis were performed. Two pepsinogens were isolated and purified from the proventriculus of the Ostrich, pepsinogens I and II. Both pepsinogens and pepsins were purified to homogeneity as shown by PAGE and SDS—PAGE, with SDS—PAGE revealing M r values of 40,400 and 41,900 for pepsinogens I and II, respectively. SDS—PAGE revealed M r values of 36,000 and 36,300 for Ostrich pepsins I and II, respectively. Ostrich pepsinogens I and II were found to have identical N-terminal sequences, with Asp as N-terminal amino acid. Amino acid compositions were obtained for both pepsinogens, with Ostrich pepsinogen I being slightly smaller in size with a total of 356 residues compared to 371 for Ostrich pepsinogen II. Pepsinogen II showed a pI of 4.29. Ostrich pepsinogens I and II were found to be immunologically separate entities, and no cross-reactivity was observed between anti-(Ostrich pepsinogen I/II) sera and porcine pepsin/pepsinogen. The study indicates that only two pepsinogens are present in the Ostrich. They differ in terms of electrophoretic mobility, molecular mass and immunological reactivity, but have been found to have identical N-terminal sequences. It is concluded that both pepsinogens belong to the pepsinogen A class of aspartyl proteases (EC 3.4.23.1).
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Ostrich trypsinogen: Purification, kinetic properties and characterization of the pancreatic enzyme
The international journal of biochemistry & cell biology, 1995Co-Authors: Mark D. Bodley, Ryno J. Naudé, Willem Oelofsen, András PatthyAbstract:Trypsinogen is a serine protease zymogen (EC.3.4.21.4) which has proved to be of key significance in a family of about 20 structurally and functionally related pancreatic digestive enzymes. This study was an endeavour to isolate, purify and characterize a stable form of Ostrich trypsinogen, which has thus far not yet been accomplished. Trypsinogen (anionic) was isolated and purified by alkaline extraction of pancreatic acetone powder, followed by Toyopearl DEAE 650M, hydroxylapatite and LBTI-Sepharose affinity chromatography. The enzyme was chemically physically and kinetically characterized, using amidase and esterase activity and spectrofluorometric determinations. Effects of CaCl2 and pH, among others, were examined. Purification of homogeneous anionic Ostrich trypsinogen was achieved. Immunochemical analysis and spectrofluorometric reaction with sulphonyl-Ala-Ala-Pro-Arg-7-amino-4-methylcoumarin indicated trypsin-free Ostrich trypsinogen, with an average Mr of 23,016 and a pI of 4.93. N-terminal sequence data revealed an unique activation peptide sequence, VPGDADDDK. Certain concentrations of Ca2+ enhanced trypsinogen activation, whilst others appeared to have the opposite effect. The kcat/Km values obtained at different pHs, using N alpha-benzoyl-DL-arginine-p-nitroanilide, p-toluenesulphonyl-arginine-methylester and p-toluenesulphonyl-lysine-methylester, followed the pH profile activity trend closely, with maximum catalytic activity at about pH 8 for both Ostrich and bovine activated trypsinogen. Ostrich trypsin has significantly higher amidase activity than bovine trypsin, while esterase activities of the two enzymes have an inverse ratio. Kinetic pKa values were 7.2 and 7.4 for Ostrich and bovine activated trypsinogens, respectively. The existence of Ostrich trypsinogen in a now homogeneous stable form, free of autocatalytic inducing impurities, together with its characterization scenario will hopefully make a significant contribution to the field of comparative biochemistry. This study also confirms that Ostrich trypsinogen is closely related to its serine protease counterparts.
T Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Purification and characterization of Ostrich prothrombin.
The International Journal of Biochemistry & Cell Biology, 2000Co-Authors: Carminita L. Frost, R Naudé, W Oelofsen, K Muramoto, T Naganuma, T OgawaAbstract:Abstract The work focused on the penultimate enzyme, prothrombin, in the coagulation cascade. Prothrombin was purified and characterized from Ostrich plasma. The results obtained contribute to a better understanding of blood coagulation in the Ostrich and the evolution of prothrombin and the coagulation cascade. Prothrombin was purified from Ostrich plasma by barium chloride precipitation, ammonium sulfate fractionation, and DEAE-cellulose and Cu2+-chelate Sepharose chromatography. Ostrich prothrombin exhibited a Mr of 72 800 and a pI of 6.9 using SDS-PAGE and PAG-isoelectrofocusing, respectively. The N-terminal sequence of Ostrich prothrombin showed 78 and 87% identity with human and bovine, respectively. The cDNA was isolated from Ostrich liver and the predicted amino acid sequence compared with those from other species. Ostrich prothrombin shares sequence identity with chicken (84%), human (60%), bovine (59%), rat (60%), mouse (59%) and hagfish (50%) prothrombin, suggesting a common function of prothrombin in these vertebrates. Amino acid sequence identities indicate that the thrombin β-chain (62%) and the propeptide-Gla (75%) domains are the regions most constrained for the common functions of vertebrate prothrombins. Ostrich prothrombin, therefore, shows similarity in structure to other vertebrate prothrombins.
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Purification and characterization of Ostrich prothrombin.
The international journal of biochemistry & cell biology, 2000Co-Authors: C Frost, R Naudé, W Oelofsen, K Muramoto, T Naganuma, T OgawaAbstract:The work focused on the penultimate enzyme, prothrombin, in the coagulation cascade. Prothrombin was purified and characterized from Ostrich plasma. The results obtained contribute to a better understanding of blood coagulation in the Ostrich and the evolution of prothrombin and the coagulation cascade. Prothrombin was purified from Ostrich plasma by barium chloride precipitation, ammonium sulfate fractionation, and DEAE-cellulose and Cu(2+)-chelate Sepharose chromatography. Ostrich prothrombin exhibited a M(r) of 72,800 and a pI of 6.9 using SDS-PAGE and PAG-isoelectrofocusing, respectively. The N-terminal sequence of Ostrich prothrombin showed 78 and 87% identity with human and bovine, respectively. The cDNA was isolated from Ostrich liver and the predicted amino acid sequence compared with those from other species. Ostrich prothrombin shares sequence identity with chicken (84%), human (60%), bovine (59%), rat (60%), mouse (59%) and hagfish (50%) prothrombin, suggesting a common function of prothrombin in these vertebrates. Amino acid sequence identities indicate that the thrombin beta-chain (62%) and the propeptide-Gla (75%) domains are the regions most constrained for the common functions of vertebrate prothrombins. Ostrich prothrombin, therefore, shows similarity in structure to other vertebrate prothrombins.
Esther Sendra - One of the best experts on this subject based on the ideXlab platform.
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Quality characteristics of Ostrich (Struthio camelus) burgers
Meat science, 2006Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, Esther Sendra, S. Jiménez, José Angel Pérez-alvarezAbstract:Quality characteristics and storage stability of three types of burgers prepared with Ostrich meat (alone or mixed with pork or beef meat) were evaluated. Burger evaluation was based on chemical, microbiological, textural, colour, sensory and oxidation characteristics. All of the assayed formulas showed acceptable general quality scores in the sensory evaluation, but the burgers formulated with 100% Ostrich meat or mixing Ostrich and beef meat had the highest scores. Only TBA values and redness were influenced by storage time. Burgers formulated with Ostrich and pork meat had a faster oxidation rate and became more oxidized than the others. Microbial counts indicated that, at the end of the refrigerated storage (9 days), all of the preparations were spoiled.
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Physical, Chemical, and Sensory Properties of Bologna Sausage Made with Ostrich Meat
Journal of Food Science, 2003Co-Authors: Juana Fernández-lópez, Estrella Sayas-barberá, C. Navarro, Esther Sendra, José Angel Pérez-alvarezAbstract:: Three formulations of bologna were prepared, differing only by the lean meat used: (1) Ostrich meat from Iliofibularis muscle (fan thigh), (2) Ostrich meat from Femorotibialis medius muscle (tip thigh), and (3) beef meat from Subscapularis muscle (shoulder). Physical, chemical, and sensory analyses were made. The final products formulated with Ostrich meat, although having a dark appearance, were acceptable in chemical composition and other sensory characteristics. The low fat and high protein content for Ostrich bolognas will help to ensure that, if marketed in sufficient quantities, Ostrich meat can successfully compete with other healthy meat products. The Ostrich meat (Iliofibularis muscle) formula reached the highest general quality scores in the sensory evaluation.
