scholarly journals Comparative characterization of starch biopolymers extracted from cereals using two different techniques

Author(s):  
Marisa Rivera-Arredondo ◽  
Mario Alberto Rodríguez-Ángeles ◽  
Verónica de Jesús Morales-Félix ◽  
Marina Gaytán-Ruelas

In the field of research and consequent elaboration of biopolymers it has been growing in the last decade, either due to the hardening of the environmental legislation of each country or due to ecological awareness, in any case the term biopolymer is quite broad, these being used as material premium in medicines, food supplements and of course in the production of bioplastics. Since the topic of interest is the comparative characterization of biopolymers using starch extracted from two different cereals, oats and rice, using the alkaline technique with NaOH treatment and the milling technique, assuming that the starch extracted from the Oryza sativa cereal presents chemical characteristics, geometric and mechanical superior in both techniques used unlike the polymers made with Avena sativa starch. These results suggest that the starch quality of each cereal is relevant for the production of biopolymers [1]. The commercially significant properties of starch, such as its mechanical strength and flexibility, depend on the strength and character of the crystalline region, which depends on the ratio of amylose and amylopectin.

Author(s):  
Marisa Rivera-Arredondo ◽  
Mario Alberto Rodríguez-Ángeles ◽  
Verónica de Jesús Morales-Félix ◽  
Mariana Gaytán-Ruelas

In the field of research and consequent elaboration of biopolymers it has been growing in the last decade, either due to the hardening of the environmental legislation of each country or due to ecological awareness, in any case the term biopolymer is quite broad, these being used as material premium in medicines, food supplements and of course in the production of bioplastics. Since the topic of interest is the comparative characterization of biopolymers using starch extracted from two different cereals, oats and rice, using the alkaline technique with NaOH treatment and the milling technique, assuming that the starch extracted from the Oryza sativa cereal presents chemical characteristics, geometric and mechanical superior in both techniques used unlike the polymers made with Avena sativa starch. These results suggest that the starch quality of each cereal is relevant for the production of biopolymers [1]. The commercially significant properties of starch, such as its mechanical strength and flexibility, depend on the strength and character of the crystalline region, which depends on the ratio of amylose and amylopectin.


Nahrung/Food ◽  
1974 ◽  
Vol 18 (3) ◽  
pp. 243-249 ◽  
Author(s):  
S. G. Kharatyan ◽  
M. G. Kerimova ◽  
A. D. Ignatyev ◽  
M. E. Rozhansky

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Gordana Оstojić ◽  
Dragica Lazić ◽  
Branko Škundrić ◽  
Jelena Penavin Škundrić ◽  
Slavica Sladojević ◽  
...  

From the aspect of their chemical and mineralogical composition, bauxites are very complex multicomponent raw materials. The paper presents the characterization of bauxite from several different deposits: Brazil, Milići, Čitluk and Kosovo. Chemical characteristics were determined by a combination of different analytical methods: gravimetry, potentiometric titration, atomic absorption spectroscopy (AAS) and UV-VIS spectrophotometry. Mineralogical composition was determined using X-ray diffraction and thermal analysis methods. Chemical and structural characterization is complemented by the results of scanning electron microscopy with EDX analysis. The information obtained was used for the assessment of the quality of investigated bauxites from the aspect of their application in the production of alumina.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Fernando José Borges Gomes ◽  
Jorge Luiz Colodette ◽  
Auphélia Burnet ◽  
Larisse Aparecida Ribas Batalha ◽  
Fernando Almeida Santos ◽  
...  

Eucalypt wood is becoming the most important raw material for the pulp industries in South America. However, due to the high wood cost in comparison to other raw material sources, nonwoody materials are also being investigated aiming at pulp production. In this way, this paper aimed at the evaluation of eighteen eucalypt clones obtained from the Brazilian Genolyptus project, regarding their potential characteristics for pulp production. Aiming at the same goal, two species of elephant grass were also evaluated as alternative raw material sources. Through the analyses of the anatomic and chemical characteristics, five eucalypt clones and one elephant grass species were indicated for pulp production and biorefinery application. The results of this study indicate the high technological quality ofEucalyptusclones evaluated and indicate that they can be used for biorefinery applications since they have the suitable characteristics. In general, the eucalypt clones are less moist and denser and contain fewer minerals and extraneous materials than the elephant grass species, which make them more attractive for utilization in deconstruction studies aiming at production of bioproducts.


Author(s):  
F. M. Fakhouri ◽  
Luan Ramos Silva ◽  
A. C. A. B. Casari ◽  
J. I. Velasco

The aim of this work was to verify the influence of drying on physical and chemical characteristics of residues from rice milk production. Residues were from the production of white, red and black rice. They were dehydrated in an oven with air circulation at 60ºC for 8h. Characterization of them were carried out by physical and chemical analyses. Residues have presented statistical difference for all parameters measured. Its characterization is necessary to justify its use in other process or application on new products.The residues from rice milk production have high content of nutrients and phenolic compounds, even after dehydration. Keywords: Nutrients; Oryza sativa; waste.


2015 ◽  
Vol 820 ◽  
pp. 8-12 ◽  
Author(s):  
Afonso Rangel Garcez de Azevedo ◽  
Jonas Alexandre ◽  
Euzébio Barnabé Zanelato ◽  
Rafael Picanço Oliveira ◽  
Rodolfo Cretton de Souza ◽  
...  

The municipal area of Campos dos Goytacazes in the northern region of the state of Rio de Janeiro, Brazil, is the state’s major industrial pole for red ceramic fabrication. The extensive clay deposits and easy to mine conditions have attracted more than one hundred ceramic industries to operate in the area. In particular, the district of São Sebastião contributes to the production of red bricks and tiles but the characterization of the existing clay and the quality of ceramic pieces has not yet been evaluated. Therefore the present work carried out an investigation of a typical clay body used in São Sebastião by means of its physical and chemical characteristics. The technological properties of red ceramics fabricated from this clay body and fired at temperatures of 700, 850 and 1100oC indicate that they comply with the mechanical strength requirements for masonry bricks. However water absorption is not satisfactory due to the excess of sand and lack of fluxing elements.


Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.


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