Search results for "Extraction"
showing 10 items of 2072 documents
Determination of fatty alcohol ethoxylates and alkylether sulfates by anionic exchange separation, derivatization with a cyclic anhydride and liquid …
2011
A method for the separation, characterization and determination of fatty alcohol ethoxylates (FAE) and alkylether sulfates (AES) in industrial and environmental samples is described. Separation of the two surfactant classes was achieved in a 50:50 methanol-water medium by retaining AES on a strong anionic exchanger (SAX) whereas most FAE were eluted. After washing the SAX cartridges to remove cations, the residual hydrophobic FAE were eluted by increasing methanol to 80%. Finally, AES were eluted using 80:20 and 95:5 methanol-concentrated aqueous HCl mixtures. Methanol and water were removed from the FAE and AES fractions, and the residues were dissolved in 1,4-dioxane. In this medium, este…
Determination of non-ionic and anionic surfactants in industrial products by separation on a weak ion-exchanger, derivatization and liquid chromatogr…
2013
Abstract A method for the determination of priority surfactants, including fatty alcohol ethoxylates (FAE), alkylether sulfates (AES) and linear alkylbenzene sulfonates (LAS) is described. The samples were diluted with 50% methanol at pH 4 prior to solid-phase extraction on a weak anionic exchanger (WAX). The AES and LAS surfactant classes were retained, whereas the non-ionic components, including most FAE oligomers were eluted. After washing the WAX cartridge to remove cations, the remaining hydrophobic FAE oligomers were eluted using hot 80% methanol at pH 4 (at ca. 50 °C). These two eluates were combined to constitute the non-ionic fraction. Then, AES and LAS were eluted using 80% MeOH w…
Accommodative intraocular lenses: current status
2005
Purpose of review The possibility of using a monofocal IOL with accommodative ability allows refractive cataract surgery with a clearly decreased potential of photic phenomena. Three IOLs of different designs and materials have demonstrated accommodative ability, but the degree of accommodative amplitude has been reported to different extents and variabilities. The plate-haptic CrystaLens has a hinged design that might permit forward movement of the optic as a result of pressure changes in the vitreous cavity. The 1CU has modified haptics that bend in the bag as the lens capsule contracts, which are supposed to cause anterior displacement of the lens optic. With the dual-optic one-piece Syn…
Effects of Extraction Conditions on Bioactive Anthocyanin Content of Vaccinium Corymbosum in the Perspective of Food Applications
2012
Abstract Bioflavonoids, in particular anthocyanins have made the topic of many scientific research, mainly for two reasons: their beneficial effects on human health and applications as potential sources of natural food dyes. Natural extracts of these pigments may also find useful application for textiles dying, as an eco-friendly alternative to synthetic dyes. The aim of the present paper was to apply conventional extraction procedures in order to isolate an enriched crude extract of pigments from highbush blueberries (Vaccinium corymbosum L.). Water, hydroalcoholic solution and acidified alcoholic solvent were tested to extract anthocyanins by a discontinuous process. Also, temperatures of…
Effects of Ultrasound-Assisted Extraction and Solvent on the Phenolic Profile, Bacterial Growth, and Anti-Inflammatory/Antioxidant Activities of Medi…
2020
© 2020 by the authors.
Negative-pressure cavitation extraction of cajaninstilbene acid and pinostrobin from pigeon pea [Cajanus cajan (L.) Millsp.] leaves and evaluation of…
2011
Abstract In this study, an efficient negative-pressure cavitation extraction (NPCE) technique was developed to extract cajaninstilbene acid (CSA) and pinostrobin (PI) from pigeon pea [Cajanus cajan (L.) Millsp.] leaves. The operating parameters were optimised using single-factor experiment and central composite design combined with response surface methodology. Well-fitting models for the extraction of CSA and PI were successfully established. From the economic perspective, the selected operating parameters were: extraction pressure −0.075 MPa, extraction temperature 45 °C, material size 40 mesh, ethanol concentration 80%, extraction time 30 min, liquid/solid ratio 30:1 and 4 extraction cyc…
Phenolic profile of oils obtained from “horchata” by-products assisted by supercritical-CO2 and its relationship with antioxidant and lipid oxidation…
2019
Abstract In this study, the effect of different supercritical CO 2 (SC-CO 2 ) pressures (10–40 MPa) on phenolic compounds extraction in oils obtained from “ horchata ” by-products was evaluated, and the results were compared to those obtained after conventional oil extraction (CE). Moreover, the relationship between the individual phenolic compounds and the total antioxidant capacity as well as oil oxidative quality parameters was compared. The phenolic profile and contents were largely influenced by extracting conditions. The main phenolic compound obtained by SC-CO 2 was the isohydroxymatairesinol, particularly at 30 and 40 MPa, while 3-vinylphenol was the predominant compound in oils ext…
The effect of ultrasonic pretreatment and sample preparation on the extraction yield of antioxidant compounds and activity of black currant fruits
2015
The aim of the study was to evaluate the efficiency of an ultrasonic pretreatment at different amplitudes and extraction times, on the content of antioxidant compounds (phenolics, anthocyanins, ascorbic acid) and total antioxidant capacity of black currant fruits. Additionally, the influence of sample preparation (frozen storage/drying) was evaluated. Extraction was performed in 60% ethanol with 0.15% HCl at a solvent-to-sample ratio of 15/1. Our results show that the ultrasonic pretreatment proved particularly useful for the recovery of high amounts of total anthocyanins in freeze-dried samples, ascorbic acid in frozen and oven air-dried samples, and total antioxidant capacity in freeze-dr…
Influence of enzyme-aided extraction and ultrasonication on the phenolics content and antioxidant activity of Paeonia officinalis L. petals
2020
Peony is a less utilized herbaceous plant of ornamental and medicinal relevance. The petals are rich in bioactive phenolics and hence, the development of efficient extraction is required for maximum recovery and bioactivity. In this study, the optimal conditions for the ultrasound-assisted extraction of peony phenolics were first investigated by comparing to conventional extraction and testing the data fit by mathematical models (linear, two factor interactions, quadratic) followed by investigation of cellulase pre-treatment combined with ultrasonication. High amounts of flavonoids, phenolics and tannins were extracted in 30 min under ultrasound conditions of 150 W, 40 kHz, 50 % amplitude, …
Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compound…
2018
Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some im…