Effect of cosmetic matrices on the release and odour profiles of the supercritical CO2 extract of Origanum majorana L.

OBJECTIVE: In this study, the effect of different cosmetic matrices on the release profile and odour intensity of the fragrance O. majorana was investigated for the first time. METHODS: The fragrance compounds of O. majorana were extracted by supercritical fluid extraction using carbon dioxide (SFE-CO2 ) at 40°C and two operating pressures (8.5 and 10 MPa), and their chemical profiles were assessed by gas chromatography with flame ionization detector coupled with mass spectrometry (GC-FID/MS). Lastly, the fragrance compounds were incorporated into three cosmetic matrices (glycerine, dipropylene glycol and skin lotion) to assess their release and odour profiles over time using dynamic headspace (DHS)/GC-FID/MS and Odour Value concept, respectively. RESULTS: The SFE-CO2 enabled recovering extracts with the pleasant scent of the living plant, and the increment of pressure induced an increase on the extraction yield. GC-FID/MS analyses revealed that oxygen-containing monoterpenes was the principal group of components identified in both SFE-CO2 extracts. The fragrance compounds were more retained in dipropylene glycol, and the major deviations from the original odour intensity (control) were observed in the presence of dipropylene glycol and skin lotion. CONCLUSION: The hydrophilic character of the cosmetic matrices strongly influenced the release of the fragrance compounds, thus affecting the odour profile of the studied mixtures.

Optimisation of reactive dye degradation by laccase using Box-Behnken design.

A three-level Box-Behnken factorial design with three factors and the Response Surface Methodology were used to optimise the colour removal of the reactive textile dye, Colour Index (C.I.) reactive red 180, by commercial laccase. A mathematical model was developed to study the effect of temperature, pH, enzyme concentration and their interactions on the decolourisation. Enzyme concentration and pH as well as their interaction were the principal factors that affected the decolourisation. The dye degradation was independent of temperature. The model estimated that the highest decolourisation (> 92%) was obtained for 27 degrees C, pH 7.5 and 85 U l(-1). This predicted value was experimentally validated, obtaining dye colour removal (540 nm) of 93 +/- 1.5%.

Natural waste materials containing chitin as adsorbents for textile dyestuffs: batch and continuous studies.

In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry. Batch equilibrium studies showed that the materials' adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents' behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials' bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass. The deproteinised Squid pen (grain size 0.500-1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20 degrees C), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.

Complexing capsules--metal extraction and modeling of ion transfer.

Polyamide complexing capsules containing a poly(acrylic acid) gel are synthesized by a two steps polymerization process with various diameters (10 microm for microcaps or 200 microm for mcaps). A cationic exchange between gel carboxylic functions and metal ions is realized. Extraction and stripping measurements show that the composition of the capsule membrane doesn't hinder the mass transfer. A model, taking account only of the diffusion in the gel phase, is studied.

Bioseparations with permeable particles.

Permeable large-pore particles have many applications, in particular in perfusion chromatography for bioseparations. The objective of this paper is to elucidate the mass transport mechanisms in two commercial adsorbents-POROS Q/M and Q Hyper D-and to answer the question if intraparticle convection is present as a mass transfer mechanism. The paper contains three sections. In the first part, mass transfer inside porous particles is discussed. The mass transfer mechanism which allows improved performance of perfusion chromatography is intraparticle convection. The combined effect of intraparticle convection and diffusion is an "augmented" effective diffusivity. This is the key concept to explain the peak sharpening and modified Van Deemter plots found with large-pore particles. In the second part, column efficiencies in terms of HETP as a function of bed superficial velocity are experimentally measured for a non-retained protein (bovine serum albumine, BSA) in two adsorbents: POROS Q/M (PerSeptive Biosystems) and Q Hyper D (BioSepra). In the third section breakthrough curves for both materials are measured for a test protein (BSA) from which useful capacities and productivities as a function of flow-rate are calculated. Experimental results indicate that intraparticle convection plays indeed an important role in both adsorbents.