Physicochemical Characteristics of Brazilian Coffea arabica cv. Catuai Coffee Extracts with Different Roasting Conditions

2019 ◽  
Vol 48 (7) ◽  
pp. 748-756 ◽  
Author(s):  
Eunkyung Kim ◽  
Yoonhwa Jeong ◽  
Sunyoung Gu ◽  
Ka-Young Song ◽  
Inyong Kim ◽  
...  
2021 ◽  
Vol 30 (2) ◽  
pp. 235-244
Author(s):  
Inyong Kim ◽  
Sunyoon Jung ◽  
Eunkyung Kim ◽  
Jin-Wook Lee ◽  
Chan-Yang Kim ◽  
...  

Author(s):  
Arezki Tagnit-Hamou ◽  
Shondeep L. Sarkar

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.


2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.


1997 ◽  
Vol 101 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Jose C. Ramalho ◽  
Thos L. Pons ◽  
Henri W. Groeneveld ◽  
M. Antonieta Nunes

Author(s):  
A. Delgado-Alvarado

Objetivo: Analizar el proceso de producción y comercialización de café en la comunidad del Cerro Cuate, Iliatenco, en la región de la Montaña de Guerrero, México.Diseño/Metodología/aproximación: el trabajo se realizó por; 1) investigación documental), 2) selección del área de estudio, 3) Entrevista estructurada con preguntas abiertas a 22 cafeticultores, soportada con la técnica de encuesta seccional y la herramienta de cédulas de entrevistas, y 4) análisis de la información. El tamaño de muestra se definió por el método de muestreo por conveniencia, y la selección de las unidades de análisis por la técnica bola de nieve. Resultados: El sistema de producción de café que predominó fue el sistema rústico de montaña, intercalado con plátano y frutales. La máxima productividad de las plantaciones se alcanza de 5.5 a 7.5años de edad, la renovación de plantas la hacen a los 12 años. El rendimiento de café fue de 3.7 kg por planta por año. La producción del café la realizan principalmente hombres (77.3%), entre 56 y 70años de edad. La venta se realiza en la presentación de café capulín a granel a intermediarios, a la ARIC, a CAFECO, a la Unión de Ejidos y a la Organización Mixtrui.Limitaciones del estudio/implicaciones: Se da una propuesta de mejora para favorecer el proceso de producción, beneficio y comercialización del café.Hallazgos/conclusiones: Coffea arabica es el principal café que se cultiva, con las variedades Typica, Caturra, Mundo Novo, Garnica y Bourbón. Los factores que limitan su producción y calidad son faltade planeación en manejo del cultivo y no contar con asesoría técnica.


Author(s):  
María Lorena Luna-Guevara ◽  
Teresita González-Sánchez ◽  
Adriana Delgado-Alvarado ◽  
María Elena Ramos-Cassellis ◽  
José Guillermo Pérez-Luna ◽  
...  

Objective: To study the effect of storage temperatures and dehydration conditions (solar and convective drying; SD, CD), on the quality, physicochemical parameters and antioxidant properties of tomato fruits. Methodology: The physicochemical characteristics pH, titratable acidity, soluble solids (°Bx) and color parameters (L*, a* and b*), were evaluated. The lycopene, carotenoids and antioxidant activity percentages retention of tomatoes fruits stored at 7 and 22 ° C for 5 days and subjected to SD (Temperature (T) of 67 °C and luminescence of 685 lum/sqf) and CD (T 70 °C, flow rates 0.5, 1.0 and 1.5 m/s), were analyzed. Results: The fruits reached humidities of 17 and 15% for SD and CD. The parameters pH, °Bx, L*, a*, b* were highest with 22°C and CD (1.5 m/s). The value of the carotenoids was higher in fruits stored at 7 ° C and subjected to CD (1.0 and 1.5 m/s) and SD with values of 83.85, 85.98 and 99.43%, respectively. The CD (0.5 m/s) and SD improved lycopene (94.37 and 95.14%) and the antioxidant activity with values of 73.06 and 97.21%. Implications: The application of solar dehydration depends on luminescence condition; however, it is inexpensive and environmentally friendly alternative. Conclusions: The results derived in a viable alternative for the conservation and commercialization of tomato fruits in rural communities


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