Effect of maltodextrin reduction and native agave fructans addition on the physicochemical properties of spray-dried mango and pineapple juices

2018 ◽  
Vol 24 (6) ◽  
pp. 519-532 ◽  
Author(s):  
Darvin E Jimenez-Sánchez ◽  
Montserrat Calderón-Santoyo ◽  
Rosa I Ortiz-Basurto ◽  
Pedro U Bautista-Rosales ◽  
Juan A Ragazzo-Sánchez
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Storage Stability ◽  
Partial Replacement ◽  
Inlet Temperature ◽  
Drying Process ◽  
Spherical Powder ◽  
Powder Particles ◽  
Spray Dried ◽  
Scanning Electron

The effects of the partial replacement of maltodextrin by native agave fructans on the characteristics of spray-dried pineapple and mango powder were evaluated in this study. An experimental 33 design, three concentrations of maltodextrin (5, 7, and 10%), three concentrations of native agave fructans (0, 2, and 4%), and three feed temperatures (110, 115, and 120  ℃) were used. The results using the treatment in which only maltodextrin was used as a reference indicated that an increment in the inlet temperature decreases the moisture content, aw, and solubility. Likewise, an increase (more than 2%) in fructans concentration generates products with increased aw, moisture, hygroscopicity, wettability, and greater solubility. Additionally, no modification of storage stability was observed. Mango and pineapple powder color were affected mainly by the inlet temperature, causing an increase in luminosity (L*) and a decrease in parameter ( a*). A scanning electron microscopy showed spherical powder particles with certain contractions; powder stability in treatments with native agave fructans was not modified in the treatment at 2%. Finally, the addition of 2% agave fructans as carrier material was able to reduce the maltodextrin concentration of the spray drying process.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

scholarly journals Influence of Strong Acid Hydrolysis Processing on the Thermal Stability and Crystallinity of Cellulose Isolated from Wheat Straw

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chemar J. Huntley ◽  
Kristy D. Crews ◽  
Mohamed A. Abdalla ◽  
Albert E. Russell ◽  
Michael L. Curry
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Cellulose Fibers ◽  
Drying Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Cellulose extractions from wheat straw via hydrochloric, nitric, and sulfuric acid hydrolysis methods were carried out. X-ray diffraction spectral analyses reveal that depending on the acid conditions used the structure of the cellulose exhibited a mixture of polymorphs (i.e., CI and CIII cellulose phases). In addition, the percent crystallinity, diameter, and length of the cellulose fibers varied tremendously as determined by X-ray diffraction and scanning electron microscopy. Thermal gravimetric analysis measurements revealed that the thermal stability of the extracted cellulose varied as a function of the acid strength and conditions used. Scanning electron microscopy analysis revealed that the aggregation of cellulose fibers during the drying process is strongly dependent upon the drying process and strength of the acids used.

The Production and Subsequent Selective Laser Melting of AlSi12 Powder

2017 ◽  
Vol 265 ◽  
pp. 434-438 ◽  
Author(s):  
P.A. Lykov ◽  
A.O. Shults ◽  
K.A. Bromer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Selective Laser Melting ◽  
Gas Jet ◽  
Laser Melting ◽  
Size And Shape ◽  
Powder Particles ◽  
Scanning Electron

The paper studies the atomization of Al-based alloy AlSi12 in gas jet. Air was used as a spraying gas. The size and shape of powder particles were studied by using scanning electron microscopy and optical granulomorphometer. The obtained powder was used in selective laser melting.

scholarly journals Morphological characterization by scanning electron microscopy of WC powder particles coated with Cu

2013 ◽  
Vol 19 (S4) ◽  
pp. 145-146 ◽  
Author(s):  
J.B. Puga ◽  
C.M. Fernandes ◽  
M.T. Vieira ◽  
A.M.R. Senos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Uniform Distribution ◽  
Powder Coating ◽  
High Energy ◽  
Homogeneous Distribution ◽  
Composite Powders ◽  
Coating Technique ◽  
Powder Particles ◽  
Scanning Electron

Cemented tungsten carbides (WC), are considered one of the oldest, most successful and commercialized powder metallurgy products. These materials are commonly composites of WC powder particles bonded with transition metals such as Co or Ni via liquid-phase sintering. WC-based composites have been used for decades in wide engineering applications, as cutting tools, components for oil and gas drilling, metal forming, among others. The conventional processing of the WC based composites initializes with powder preparation, performed by wet milling of all the powder components (WC and metallic binders). However, this process is high energy consuming, ecologically unfriendly and longstanding, thus new powder processing methods are welcome. In this work, copper (Cu) was selected as an alternative binder, due to its inability to form brittle carbides with WC at higher temperature, the superior ductility (compared with the traditional Co binder) and corrosion resistance. Nevertheless, melted Cu has low wettability on the WC surfaces, limiting the attained sintered density and, consequently, the final properties. Powder coating techniques, such as high energy ball milling (HEBM) and the sputter-coating technique (ST), improve the binder homogeneous distribution and nanostructuring enhancing the sinterability. WC-Cu composite powders (with 2 wt.% Cu) were prepared using the two methods mentioned above. The morphology of the particles was evaluated by scanning electron microscopy (SEM- Hitachi SU-70) and the distribution and chemical composition were assessed by energy dispersive spectroscopy (EDS- Bruker QUANTAX 400).The starting WC powder has an average grain size of 9 µm, as depicted in Figures 1-a) and 2-a). In the WC coating by HEBM, the collisions of ball-to-ball and ball-to-wall with the entrapped powder particles cause at the same time severe binder plastic deformation and WC fragmentation, endorsing a high uniform distribution of Cu around WC particles, as is depicted in Figures 1-b) and c). On the other hand, the composite powders prepared by ST revealed a high uniformity of Cu coating on the WC particles (Figures 2-b) and c)), together with a columnar binder nanostructure, commonly observed on sputter–coated surfaces. In spite of the low binder content, the WC particles seem well covered, taking its rough morphology, in Figure 2-c), and the X- ray maps and the Cu, W concentration profiles presented in Figure 3. It can be, therefore, concluded that both powder coating techniques allow high uniform distribution of Cu coatings on WC particles and, furthermore, the ST technique presents a clear nanometric binder structure. The effect of the coating technique on the sinterability of WC-Cu powders will be evaluated on forthcoming studies.

Microstructural modification upon hydrogen cycling of MgH2 nanocomposites

2011 ◽  
Vol 1334 ◽  
Author(s):  
A. Montone ◽  
A. Aurora ◽  
D. Mirabile Gattia ◽  
M. Vittori Antisari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Evolution ◽  
Base Material ◽  
Oxide Shell ◽  
Microstructural Modification ◽  
Innovative Method ◽  
Powder Particles ◽  
Scanning Electron

ABSTRACTThe morphological evolution of Mg based powders during repeated absorption-desorption reactions with hydrogen has been studied by Scanning Electron Microscopy. The main feature observed is the presence, after several cycles, of surface protrusions probably constituted by the base Mg material without the presence of a catalyst. The effect is present both in catalyzed and non-catalyzed materials and it is considered an indication of the tendency of the base material to exit from the oxide shell surrounding the Mg powder particles. This tendency is confirmed by the observation of empty MgO boxes indicating that the effect can push until a complete expulsion of the base material. This effect can represent the base for an innovative method for cleaning the surface of a tank material by an “in situ” procedure.

Morphological Structures of Rabbit Hair

2011 ◽  
Vol 332-334 ◽  
pp. 1063-1066 ◽  
Author(s):  
Qiu Ting Zheng ◽  
Yi Zhang ◽  
Meng Xing Yang ◽  
Hua Wu Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Fiber Diameter ◽  
Morphological Structure ◽  
Partial Replacement ◽  
Excellent Performance ◽  
Scale Layer ◽  
Scanning Electron

Rabbit hair has been expected to be a partial replacement of cashmere, due to its excellent performance and relatively cheaper price. However, the attempt has not been successful, since the morphological structure of the rabbit hair is quite different from other animal hairs. The literature regarding rabbit hair is fairly rich, but the morphology of rabbit hair is too complex to make a very certain conclusion. Hence, the morphological structure of rabbit hair was investigated again in this study, using optical microscopy and the scanning electron microscopy. The basic shape of the hair scale, the cortex distribution and the medulla of different fineness were studied. It was founded that no medulla existed when the diameter was less than 10um. When the fiber diameter was between 10um and 20um, there was normally one medulla layer. Two and three medulla layers occurred when fiber diameter was between 20um and 30um. When the diameter was more than 50um, multi-layers of medulla presented. Keywords: Rabbit Hair, Morphological Structure, Scale Layer, Cortex Layer, Medulla Layer.

scholarly journals The effect of infrared drying to the microstructural structure and texture of whole Duku intact skin by means of scanning electron microscopy (SEM) technique

10.5219/1234 ◽  
2020 ◽  
Vol 14 ◽  
pp. 292-299
Author(s):  
Laila Rahmawati ◽  
Daniel Saputra ◽  
Kaprawi Sahim ◽  
Gatot Priyanto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Shelf Life ◽  
Exposure Time ◽  
Visual Analysis ◽  
Drying Process ◽  
Infrared Emitter ◽  
Infrared Method ◽  
Visual Depiction ◽  
Scanning Electron

The Infrared method has the potential to extend the shelf life of duku fruit by drying the duku’s skin into "shell likeness". Duku’s skin drying using infrared method could change the shape and characteristics of duku’s skin which would significantly affect the length of fruit shelf life. The texture of duku’s skin for the treatment of infrared emitter distance of 6 cm, temperature of 400 °C and exposure time of 80 seconds was increasing with the storage time which made the fruit inside the skin to experience a passive modified atmosphere and increase the shelf life of duku. The 3D visual depiction of the optimization result on drying process using infrared had the largest porosity and cavity value in the treatment of infrared emitter distance of 10 cm, temperature of 300 °C, and exposure time of 80 seconds. At the magnification of 2500 times, with a resolution of 10 mm, it was found that the porosity and thickness of the duku’s void were greater than duku fruit without treatment. The result of the porosity also found that drying process with the infrared emitter distance of 6 cm at temperature of 400 °C, and exposure time of 80 seconds has more stable porosity (without collapsing) which confirmed the result found on the texture of the skin. The results of scanning electron microscopy analysis and 3D visual analysis confirmed the results of optimization that had previously performed in the drying process of duku fruit using infrared method.

Characterization of Atomized Powders and Extruded Samples of an Al-Si-Cu Alloy

2017 ◽  
Vol 899 ◽  
pp. 442-447
Author(s):  
Carlos Triveño Rios ◽  
C. Bolfarini ◽  
Walter José Botta Filho ◽  
Claudio Shyinti Kiminami
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Yield Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy ◽  
Powder Particles ◽  
Scanning Electron

In this work, the microestrutural characterization and mechanical properties of atomized Al-9Si-3Cu alloy powders and extruded samples are presented. The microstructure was evaluated by a combination of X-ray diffraction, optical microscopy and scanning electron microscopy. The mechanical properties of extruded samples were also characterized by tensile test and hardness measurements. The results revealed that the powder particles and the extruded samples are constituted by α-Al, intermetallic and metastable phases. The extruded samples obtained by the use of smaller atomized particles show lower ductility than with larger particles. The same behavior was observed with low extrusion temperature than with high temperatures. It was also observed minor variations in the yield strength and hardness with variation in the size of the powder particles.

Total and Partial Replacement of Quartz in Aluminum Hydroxides Porcelain Formulations

2014 ◽  
Vol 798-799 ◽  
pp. 289-293
Author(s):  
Guilherme Gralik ◽  
Adriana Scoton Antonio Chinelatto ◽  
Adilson Luiz Chinelatto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Water Absorption ◽  
Aluminum Hydroxide ◽  
Raw Materials ◽  
Partial Replacement ◽  
X Ray ◽  
Aluminum Hydroxides ◽  
Scanning Electron

Alumina has been studied as a substitute for quartz triaxial porcelain formulations, but the high cost of the alumina raises the cost of production. The use of aluminum hydroxide from the Bayer process for obtaining aluminum, a source of alumina, is an alternative to alumina. In this work we used two aluminum hydroxides to replace the quartz composition of triaxial porcelain. The raw materials used were characterized by analysis of particle size distribution, scanning electron microscopy, diffraction and X-ray fluorescence. The compositions sintered were characterized by apparent density, apparent porosity, water absorption, flexural strength, and X-ray diffraction and scanning electron microscopy. Both the total and partial replacement of quartz by aluminum hydroxide showed good results with high flexural strength, low water absorption and low porosity.

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