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1.
Molecules ; 17(8): 8968-81, 2012 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-22842642

RESUMO

Dry matter, organic acids, ascorbic acid, minerals (nitrogen, phosphorus, potassium, calcium, magnesium, sodium) and polyphenolic profile of a number of non-traditional fruit species and their genotypes, namely blue honeysuckle (Lonicera spp.), Saskatoon berry (Amelanchier alnifolia), black mulberry (Morus nigra), Tomentosa cherry (Prunus tomentosa Thunb.) and jostaberry (Ribes nigrum x Grossularia uva-crispa) were investigated. The results showed that Lonicera genotypes displayed high levels of ascorbic acid and they were rich in minerals, with the cultivar 'Amfora' achieving the leading position in nitrogen, phosphorus and potassium content among all lesser known fruit species. Amelanchier cultivars represented a valuable source of ascorbic acid and calcium, 'Tisnovský' and 'Smoky' together with Morus nigra 'Jugoslavska' accumulated the highest level of examined polyphenolic compounds. Regular consumption of studied less common fruit species can bring health benefits so they can represent a high potential value for fruit growers and in addition they can be utilised as functional foods.


Assuntos
Frutas/química , Valor Nutritivo , Extratos Vegetais/análise , Polifenóis/análise , Ácidos não Carboxílicos/análise , Ácidos não Carboxílicos/isolamento & purificação , Ácidos Carboxílicos/análise , Ácidos Carboxílicos/isolamento & purificação , República Tcheca , Genótipo , Lonicera/química , Minerais/análise , Minerais/isolamento & purificação , Morus/química , Extratos Vegetais/isolamento & purificação , Polifenóis/isolamento & purificação , Prunus/química , Ribes/química , Rosaceae/química
2.
Bioresour Technol ; 130: 522-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23334006

RESUMO

The catalytic performance and recoverability of several homogeneous acid catalysts (hydrochloric, sulfuric, and nitric acids) for the esterification of enzyme-hydrolyzed free fatty acid (FFA) and methanol were studied. Although all tested catalysts drove the reaction to a high yield, hydrochloric acid was the only catalyst that could be considerably recovered and reused. The kinetics of the esterification reaction catalyzed by hydrochloric acid was investigated under varying catalyst loading (0.1-1M), reaction temperature (303-343K), and methanol/FFA molar ratio (1:1-20:1). In addition, a pseudo-homogeneous kinetic model incorporating the above factors was developed. A good agreement (r(2)=0.98) between the experimental and calculated data was obtained, thus proving the reliability of the model. Furthermore, the reusability of hydrochloric acid in FFA esterification can be predicted by the developed model. The recoverable hydrochloric acid achieved high yields of FFA esterification within five times of reuse.


Assuntos
Ácidos não Carboxílicos/química , Biocombustíveis , Ácidos Graxos não Esterificados/química , Ácidos não Carboxílicos/isolamento & purificação , Catálise , Esterificação , Ácidos Graxos não Esterificados/metabolismo , Cinética , Metanol/química , Modelos Químicos , Temperatura
3.
Environ Sci Technol ; 40(1): 370-6, 2006 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16433374

RESUMO

Many industrial unit operations and unit processes require near-complete removal of hardness to avoid scaling in heat-transfer equipment, fouling in membranes, and high consumption of detergents and sequestering chemicals in cooling and wash water. Lime softening and cation exchange are the most commonly used processes practiced to date for hardness removal. Herein, we report and discuss the results and attributes of a new hardness removal process using ion-exchange fibers (IX-fibers). Most importantly, the process uses harvested snowmelt (or rainwater) as the regenerant chemical along with sparged carbon dioxide. Consequently, the spent regenerant does not contain a high concentration of aggressive chemicals such as sodium chloride or acid like traditional ion-exchange processes nor does the process produce voluminous sludges similar to lime softening. The bulk of carbon dioxide consumed during regeneration remains sequestered in the aqueous phase as alkalinity. IX-fibers form the heart of the process. They are essentially thin cylindrical polymeric strands 10-20 microm in diameter. The weak-acid carboxylate functional groups reside near to the surface of these cylindrical fibers. Low intraparticle diffusional resistance is the underlying reason IX-fibers are amenable to efficient regeneration with snowmelt sparged with carbon dioxide. When the carbon dioxide partial pressure is increased to 6.8 atm, over 90% calcium desorption efficiency is obtained. On the contrary, commercial weak-acid ion-exchange resins in spherical bead forms are ineffective for regeneration with carbon-dioxide-sparged snowmelt due to extremely slow ion-exchange kinetics involving counter-transport of Ca2+ and H+.


Assuntos
Resinas de Troca Iônica/química , Neve , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Abastecimento de Água , Ácidos não Carboxílicos/isolamento & purificação , Adsorção , Ânions/química , Cálcio/química , Dióxido de Carbono/química , Ácidos Carboxílicos/isolamento & purificação , Dureza , Hidrogênio/química , Cinética , Chuva , Cloreto de Sódio/isolamento & purificação , Purificação da Água/instrumentação
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