Physical forms of MIPs.

The current state of the art in the development of methodologies for the preparation of MIPs in predetermined physical forms is critically reviewed, with particular attention being paid to the forms most widely employed in practical applications, such as spherical beads in the micro- to nanometer range, microgels, monoliths, membranes. Although applications of the various MIP physical forms are mentioned, the focus of the paper is mainly on the description of the various preparative methods. The aim is to provide the reader with an overview of the latest achievements in the field, as well as with a mean for critically evaluating the various proposed methodologies towards an envisaged application. The review covers the literature up to early 2010, with special emphasis on the developments of the last 10 years

Valorisation of grape pomace by the extraction of phenolic antioxidants: Application of high voltage electrical discharges.

International audienceThe aim of this study was to optimise the electrically assisted extraction in order to obtain grape pomace extracts with high polyphenols content, which would be potentially interesting for applications as natural antioxidants. High voltage electrical discharges (HVED) were applied for intensification of the extraction. The effects of the energy input, the electrodes distance gap and the liquid-to-solid ratio were studied. Diffusion was then carried out in different mixtures of water and ethanol for one hour at 20, 30, 40 and 60 °C. The most efficient extraction was (i) an HVED pre-treatment at 80 kJ/kg with an electrodes distance of 5 mm in a liquid-to-solid ratio of 5 followed by (ii) a diffusion with 30% ethanol in water at 60 °C for 30 min. The highest total polyphenols content reached 2.8 ± 0.4 gGAE/100gDM with a corresponding antioxidant activity of 66.8 ± 3.1 gTEAC/kgDM. The polyphenols extraction rate increased with temperature in accordance to an Arrhenius type of relationship: activation energy of 21.5 ± 1.1 kJ/mol for HVED treated systems against 0.5 ± 0.2 kJ/mol for untreated ones

Valorisation of grape pomace by the extraction of phenolic antioxidants: Application of high voltage electrical discharges.

International audienceThe aim of this study was to optimise the electrically assisted extraction in order to obtain grape pomace extracts with high polyphenols content, which would be potentially interesting for applications as natural antioxidants. High voltage electrical discharges (HVED) were applied for intensification of the extraction. The effects of the energy input, the electrodes distance gap and the liquid-to-solid ratio were studied. Diffusion was then carried out in different mixtures of water and ethanol for one hour at 20, 30, 40 and 60 °C. The most efficient extraction was (i) an HVED pre-treatment at 80 kJ/kg with an electrodes distance of 5 mm in a liquid-to-solid ratio of 5 followed by (ii) a diffusion with 30% ethanol in water at 60 °C for 30 min. The highest total polyphenols content reached 2.8 ± 0.4 gGAE/100gDM with a corresponding antioxidant activity of 66.8 ± 3.1 gTEAC/kgDM. The polyphenols extraction rate increased with temperature in accordance to an Arrhenius type of relationship: activation energy of 21.5 ± 1.1 kJ/mol for HVED treated systems against 0.5 ± 0.2 kJ/mol for untreated ones

Grape seeds valorization: extraction of polyphenols by electrical treatments and ultrasound

19th International Congress of Chemical and Process Engineering - CHISA 2010 & 7th European Congress of Chemical Engineering - ECCE-7, Prague, Czech Republic, 28 August - 1 September 2010