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Extraction Medium (extraction + medium)
Selected AbstractsEvaluation of the extraction efficiency for polyphenol extracts from by-products of green kiwifruit juicingINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 12 2009Dongxiao Sun-Waterhouse Summary The health benefits of fruits are attributable in part to their bioactive components such as phenolics and pectic polysaccharides. By-products derived from kiwifruit processing can be a good source of such bioactive compounds. Extracts were produced using different concentrations of ethanol in water (0%, 30%, 50%, 74% and 96% v/v) from by-products (skin, residue and pulp) of the green-fleshed kiwifruit (Actinidia deliciosa,Hayward') juicing process. The amounts of phenolic compounds and uronic acid (UA) as well as the phenolic composition in each extract were determined. Results show that different by-products contained different concentrations of phenolics and pectic polysaccharides. Based on total phenolic contents, 96% v/v ethanol appeared to be the best extraction medium. The 30% or 74% ethanolic dilution was the second best medium for phenolic extraction from skin and pulp/residue, respectively. Water was a good medium for extracting satisfactory quantities of phenolics as well as the highest concentration of pectic polysaccharides. Phenolic profiling by high-performance liquid chromatography (HPLC) was used to detect individual phenolic compounds in an extract. Results using HPLC showed that alkali pre-treatment has improved the extraction efficiency of phenolics as a function of alkali concentration, fruit tissue type, extraction media, by-product preparation method, and class of polyphenols. As a result more efficient methods for both extraction and characterisation of polyphenols could be evaluated. [source] Cell removal with supercritical carbon dioxide for acellular artificial tissueJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2008K. Sawada Abstract BACKGROUND: The objective of this work was to decellularize artificial tissue without using surfactant solutions. For this purpose, supercritical carbon dioxide was used as the extraction medium. RESULTS: Supercritical carbon dioxide containing a small amount of entrainer was a suitable medium to extract both cell nuclei and cell membranes from artificial tissue. Under gentle extraction conditions (15 MPa, 37 °C), cell nuclei were satisfactorily extracted from tissue within 1 h. In contrast, the efficiency of phospholipid removal depended strongly on the transfer rate of carbon dioxide in the interior of the tissue. Mechanical strength of tissue was not decreased even with prolonged treatment. CONCLUSION: Acellular artificial tissues could be prepared quickly by treatment with a carbon dioxide/entrainer system. The prepared acellular tissue could be obtained in absolutely dry condition. This is advantageous from the viewpoint of long-term preservation without putrefaction and contamination. Copyright © 2008 Society of Chemical Industry [source] Surface derivatization of poly(p -phenylene terephthalamide) fiber designed for novel separation and extraction mediaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 17 2005Akira Abe Abstract The surface derivatization of poly(p -phenylene terephthalamide) fiber was studied. The obtained surface-derivatized filaments were packed into a fused-silica capillary to evaluate its surface characteristics by using GC. As the stationary phase for GC the surface-derivatized fibers showed higher retention for alkanes and alkylbenzenes than that with the untreated Kevlar fiber. The improvements on the retention power and the peak shape were observed on the benzyl-modified fibrous stationary phase. The derivatized fibrous materials were also evaluated as the extraction medium in fiber-in-tube SPE, and the effect of the surface modification on the extraction power was compared to the parent fiber. The results indicated that the modified fiber possessed a higher extraction power than the untreated fiber. Based on the facts, the successful modification of the fiber surface was estimated. [source] Speciation of essential and toxic elements in edible mushrooms: size-exclusion chromatography separation with on-line UV,inductively coupled plasma mass spectrometry detectionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2004Rodolfo G. Wuilloud Abstract Size-exclusion liquid chromatography was coupled to UV and inductively coupled plasma mass spectrometry (ICP-MS) for detection to perform elemental speciation studies on different edible mushrooms. Molecular weight (MW) distribution patterns of several elements among different fractions present in various edible mushrooms are presented. The association of the elements with the high and low MW fractions was observed using sequential detection by UV and ICP-MS. Separation was performed using a Superdex 75 column. Variability of the fractionation patterns with three different extraction media (0.05 mol l,1 NaOH; 0.05 mol l,1 HCl; hot water at 60°C) was evaluated for mushroom species. A comparative elemental speciation study was performed in order to determine the differences in the fractionation patterns of silver, arsenic, cadmium, mercury, lead, and tin in Boletus edulis, Agaricus bisporus, and Lentinus edodes. Differences in the fractionation patterns of the elements were found to depend on the mushroom species and the extraction medium. Most of the elements were associated with high mw fractions. It was not possible to assess the trace metal contributions from the mushroom growth media. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||