Effect of Commercial Starter Cultures on the Myofibrillar Proteins of Pastirma, a Turkish Dry Meat Product

ABSTRACT: The effect of 3 different commercial starter cultures ( Staphylococcus carnosus, Staphylococcus carnosus + Lactobocillus pentosus and Staphylococcus xylosus + Lactobacillus sakei ) on the myofibrillar proteins of pastirma was investigated. It was observed that using commercial starter cultures in pastirma manufacture had a significant effect on myofibrillar fragmentation. However, the effect of each starter culture on myofibrillar fragmentation in pastirma was different. Most of the changes in myofibrillar proteins were produced with S. carnosus + L. pentosus.     

3‐Substituted Indazoles as Configurationally Locked 4EGI‐1 Mimetics and Inhibitors of the eIF4E/eIF4G Interaction

4EGI‐1, the prototypic inhibitor of eIF4E/eIF4G interaction, was identified in a high‐throughput screening of small‐molecule libraries with the aid of a fluorescence polarization assay that measures inhibition of binding of an eIF4G‐derived peptide to recombinant eIF4E. As such, the molecular probe 4EGI‐1 has potential for the study of molecular mechanisms involved in human disorders characterized by loss of physiological restraints on translation initiation. A hit‐to‐lead optimization campaign was carried out to overcome the configurational instability in 4EGI‐1, which stems from the E‐to‐Z isomerization of the hydrazone function. We identified compound 1 a , in which the labile hydrazone was incorporated into a rigid indazole scaffold, as a promising rigidified 4EGI‐1 mimetic lead. In a structure–activity relationship study directed towards probing the structural latitude of this new chemotype as an inhibitor of eIF4E/eIF4G interaction and translation initiation we identified 1 d , an indazole‐based 4EGI‐1 mimetic, as a new and improved lead inhibitor of eIF4E/eIF4G interaction and a promising molecular probe candidate for elucidation of the role of cap‐dependent translation initiation in a host of pathophysiological states.     

采用冷却倾斜板铸造方法生产悬架零部件用EN Aw 6082铝合金锻坯(英文)

对采用冷却倾斜板铸造方法生产EN AW 6082铝合金锻坯用于制备悬架零部件的可行性进行研究。采用冷却倾斜板铸造方法生产的EN AW 6082铝合金坯料具有细小的均匀组织,可直接用于锻造生产而不需要另外的均匀化处理。这可能是因为铸造开始时采用较小的过热和冷却倾斜板上发生较多的凝固所致。对采用冷却倾斜板铸造和均匀化处理的含或者不含Cr的EN AW 6082铝合金坯料,通过锻造生产的悬架零部件均具有均匀的组织,经过标准的人工时效处理后硬度可达到HV110。     

Synthesis and Properties of La2O3-Doped 8 mol% Yttria-Stabilized Cubic Zirconia

In this study, 8 mol% yttria-stabilized cubic zirconia (8YSZ) powder as a matrix material and 0-15 wt.% La₂O₃ powder as an additive were used to determine the effect of La₂O₃ addition and its amount on the phase stability, microstructure, sintering, and mechanical properties of 8YSZ. Colloidal processing was used to mix the powders uniformly and to obtain a homogenous microstructure. XRD results showed the existence of only a cubic crystal structure for 1 and 5 wt.% La₂O₃ addition amounts. However, La₂Zr₂O₇ with a hexagonal and cubic crystal structure was observed in 8YSZ specimens doped with 10 and 15 wt.% La₂O₃. Further, up to 5 wt.% La₂O₃ was completely dissolved in the crystal structure of the specimens; however, above 5 wt.%, La₂O₃ reacted with 8YSZ at high temperatures and formed pyrochloric La₂Zr₂O₇. Grain size measurements revealed that the grain size of 8YSZ increased up to 1 wt.% La₂O₃ addition, and then decreased beyond this amount. The hardness and fracture toughness of 8YSZ decreased and increased, respectively, with the increasing La₂O₃ amount.     

Effect of Cr and Zr on the grain structure of extruded EN AW 6082 alloy

The effects of Cr and Zr addition on the coarse grain surface layer in EN AW 6082 tube extrusions were investigated. The decoration of the tube surfaces and the weld seams with coarse recrystallized grains reflects the strain as well as the temperature gradients that predominate across the section of the tubes during extrusion. The recrystallization resistance provided by Mn does not suffice to avoid the coarse surface grains. With structural features that are almost identical to those of the base 6082 alloy, the 6082 alloy with 0.06 wt% Zr also fails to offer any improvement. The coarse grain surface layer is much thinner and recrystallization is entirely avoided across the weld seams upon the addition of 0.15 wt% Cr. The superior recrystallization resistance of the revised alloy is attributed to the increase in the population of the Cr-rich Al(Cr,Mn,Fe)Si as well as (Al, Si)₃Zr dispersoid particles. It is reasonable to conclude that the coaddition of Zr and Cr has a favourable impact on the resistance to recrystallization of EN AW 6082 alloy.     

Ultrasonic characterization of lactose dissolution

The ultrasonic properties (at 2.25 MHz) of lactose solutions and suspension of lactose crystals (d ∼ 50 μm) were measured as a function of concentration (0–40 wt.%). Ultrasonic velocity increased linearly with concentration regardless of the state of dissolution of the lactose crystals while ultrasonic attenuation was low and concentration-independent when the lactose was dissolved and increased approximately linearly with the concentration of suspended crystals. Therefore the amount of lactose present and the state of dissolution can be determined simultaneously with single ultrasonic sensor. A sensor based on this principle was applied to a stirred tank and used to measure the time taken to mix powdered lactose into a solution and the time for the added lactose to dissolve.     

Effects of electroplasmolysis treatment on chlorophyll and carotenoid extraction yield from spinach and tomato

In this study, the effects of electroplasmolysis on β-carotene, chlorophyll-a, chlorophyll-b and total chlorophyll contents of spinach extract and β-carotene and lycopene contents of tomatoes extracts were investigated. Three different voltage gradients (40, 60, 80 V/cm) and three different application periods (4, 8, 12 s) were used. The effects of water bath heating at different temperatures on the extraction yield of colorants were also studied. After pre-treatments, β-carotene, lycopene, chlorophyll-a, and chlorophyll-b extraction was performed. Total solid content, pH and titratable acidity of the spinach and tomato samples were also determined.In spinach, the highest extraction yield efficiency for β-carotene (19.7%) was obtained by water bath heating. The extraction yield efficiencies for chlorophyll-a, chlorophyll-b and total chlorophyll were 14.9%, 12.6% and 13.7% respectively, by the electroplasmolysis treatment at 60 V/cm for 8 s. In tomato, the highest increase in extraction yield efficiencies of β-carotene (139.1%) and lycopene (112.4%) was obtained by electroplasmolysis treatment at 80 V/cm for 4 s.     

Microbiological profile of helva sold at retail markets in Izmir city and the survival of Staphylococcus aureus in this product

The objective of this research was to determine the microbiological profile of tahin helva, a low moisture confectionery. A total of 63 tahin helva samples were collected from the retail markets in Izmir, Turkey. These samples were examined by standard procedures for aerobic plate count (APC) and counts of moulds and yeasts, Enterobacteriaceae, Staphylococcus aureus and Salmonella spp. APC of samples ranged from <10 to 1.6 × 10⁵ cfu/g. The counts for moulds, yeasts and Enterobacteriaceae ranged from <10 to 1.8 × 10³, <10 to 7 × 10², <10 to 8.5 × 10² cfu/g, respectively. None of the samples contained S. aureus or Salmonella. The potential for survival of S. aureus in the product stored at refrigeration (4 °C) and room (20 °C) temperatures was evaluated by artificial contamination. S. aureus cells were still recovered after 9 months of storage at both temperatures. The results of this investigation indicate that S. aureus contamination of tahin helva, (a_w of 0.172) may constitute a potential public health hazard, depending on the extent of contamination and mishandled exercise at the sale area and the kitchen.     

A preliminary study on the manufacturing aluminum–potassium feldspar metal matrix composite materials

This study reports the results of a preliminary study of manufacturing aluminum–potassium feldspar metal matrix composites including its castability and mechanical properties. The material was composed considering 0.25 %, 0.5 %, and 0.75 % additive ratios to examine the impact of the amount of potassium feldspar on the material and mechanical properties of the manufactured aluminum metal matrix composite material. Aluminum alloy (A356) was utilized as the matrix of the composition. The composite material was manufactured by the stir casting technique. The modulus of elasticity, yield strength, tensile strength, elongation, density, and quality index of the material parameters was taken into account to determine the materials′ practicality. The preliminary results indicated that potassium feldspar is a promising mineral to be utilized as an additive for aluminum metal matrix composites since it has a positive impact on mechanical properties. By optimizing the casting parameters, the positive aspects of the potassium feldspar may make the material more practical to be utilized in vast engineering applications.