The Electrophoretic Profile Myofibrillar Proteins Extracted From Camel Muscles, Kept in Various Modes

Changes in electrophoretic profiles of myofibrillar protein (MFP) in the Longissimus thoracis (LD) of young camels (2 to 4 years), preserved by refrigeration has been treated or not by lactic acid solution 4% or citric acid 1%, were followed during the post-mortem time at the following times: 1, 2, 4, 6, 8, 10, 12, 24 and 48 hours. The cold preservation for 48 hours has not shown any particular distinctions in the protein profiles of this muscle. Changes related to the type of treatment were recorded during the storage time. Proteolysis of the myofibrillar fraction was earlier in this muscle in the case of treatment with one of two solutions of organic acids used, particularly in the case of using lactic acid. Indeed, these changes have affected at the first hour after slaughter the proteolysis of the myofibrillar proteins. Fragments of low molecular weight (42, 36, 33, 26, 23, 18, 16, 14 and 13 kDa) have been identified. The electrophoretic analysis showed that during refrigeration, LD treated with a solution of lactic acid is more sensitive to disruption phenomena and muscle protein proteolysis that lots of this muscle that even in the case of preservation by refrigeration only or by refrigeratio

Temperature-dependent structural and magnetic properties of mechanically alloyed Ni80Co17Mo3 powder mixture

Nanostructured materials containing nickel improve the effectiveness of several applications. This study examines the preparation and characterization of nanostructured Ni80Co17Mo3 alloy powders using high-energy mechanical alloying and subsequent annealing. A 72 h milling process used pure elemental powders to synthesise nanocrystalline FCC-NiCo(Mo) solid solution. The milled powders were then subjected to annealing at different temperatures:300◦C, 500◦C, and 750◦C. X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and vibrating sample magnetometry indicated significant changes in the powdered alloy properties. The particles growth occurred as the annealing temperature increased, while the microstrain decreased significantly; 14.30±0.07 nm up to 56.30±0.28 nm and 0.680±0.003 % up to 0.180 ±0.001 %, at 25◦C and 750◦C respectively. SEM analysis revealed differences in particle size and shape as milling progressed. Surprisingly, the milled powdered alloy displayed improved magnetic properties, manifesting significant magnetic susceptibility and enhanced saturation magnetisation, remanent magnetisation, and coercivity within the temperature range of 300◦C to 750◦C. These findings indicate the development of a consistent and structured state, accompanied by significant crystal growth due to the annealing temperature. This study highlights the great importance of high-energy mechanical milling and subsequent annealing to tune / tailor the characteristics and subsequently investigate the potential utilization of nanostructured Ni-based alloys

Temperature dependence of the electrical resistivity and absolute thermoelectric power of amorphous metallic glass Ni33.3Zr66.7

International audienceElectron transport properties and thermal stability of Ni33.3Zr66.7 metallic glass (MG) have been studied using an original device for simultaneous measurements of electrical resistivity and absolute thermoelectric power (ATP) controlled by a LabView software written by one of us. The electrical resistivity and absolute thermoelectric power were measured simultaneously and very accurately over a temperature range from 25 to 400 °C with a nominal heating rate of 0.5 K min− 1. The electronic thermal conductivity was also determined using the Wiedemann–Franz law in the same temperature range. Due to its high efficiency, this technique is more and more used because it is characterized by a high sensitivity to detection of the phase transitions related to electronic transport, which is the aim of this study. Analysis of the temperature dependence of the resistivity and ATP of the Ni33.3Zr66.7 glassy ribbons proves the potential of this characterization method to study the thermal behavior of metallic glasses. The crystal structure and the morphology of Ni33.3Zr66.7 metallic glass in the as-quenched state and after heat treatments were studied using X-ray diffraction (XRD), and scanning electron microscope (SEM)

Postmortem Muscle Protein Changes as a Tool for Monitoring Sahraoui Dromedary Meat Quality Characteristics

The effects of slaughter age (2 vs. 9 years) and postmortem time (6, 8, 10, 12, 24, 48 and 72 h) on the meat quality and protein changes of the longissimus lumborum muscles of the Algerian Sahraoui dromedary were investigated. Muscles of young dromedaries evidenced a slower acidification process and a significantly higher myofibrillar fragmentation index throughout the postmortem time. The SDS-PAGE of sarcoplasmic and myofibrillar proteins revealed that meat from young dromedaries was characterized by the lowest percentage of myoglobin (p < 0.001) and the highest percentage of desmin (p < 0.01). During postmortem time, a decrease was found for phosphoglucomutase (p < 0.01), α-actinin (p < 0.05) and desmin (p < 0.01) in meat from young dromedaries. Western blot revealed an intense degradation of troponin T in younger dromedaries, with an earlier appearance of the 28 kDa polypeptide highlighting differences in the proteolytic potential between dromedaries of different ages. Principal component analysis showed that meat from young dromedaries, starting from 24 h postmortem, was located in a zone of the plot characterized by higher levels of the myofibrillar fragmentation index, 30 kDa polypeptide and enolase, overall confirming greater proteolysis in younger animals. Data suggest that the investigation of the muscle proteome is necessary to set targeted interventions to improve the aging process of dromedary meat cuts