Elias Bou-Maroun

Molecularly imprinted polymer solid phase extraction of fungicides from wine samples

In order to preconcentrate iprodione fungicide in white wine samples, molecularly imprinted polymers (MIPs) specific for iprodione were synthesized using two polymerization approaches: precipitation (MIPp) and bulk polymerization (MIPb). A comparison of the performance of the MIPs and the corresponding non-imprinted polymers (NIPs) was conducted in batch studies. In this case, the MIPp revealed better recognition properties toward iprodione in wine samples than the MIPb. The MIPp and MIPb were then used as sorbents on solid phase extraction cartridges (MISPEp and MISPEb consecutively) in order to pre-concentrate iprodione from white wine samples. The optimization of the MISPE elution step was done using MIPp and acetonitrile was shown to be the best eluting solvent. MISPEp showed better iprodione recovery and pre-concentration factor than MISPEb. The selectivity of the MISPE method for iprodione was evaluated in white wine samples in the presence of two other fungicides, pyrimethanil and procymidone. MISPEp was very selective for iprodione compared with the two other fungicides. However, MISPEb was able to preconcentrate iprodione as well as its analogues.

Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media.

An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be more efficient than the nonimprinted polymer for the uptake of iprodione, as revealed by its higher adsorption energy, affinity, and capacity. Finally, a selectivity study was conducted on the imprinted and the nonimprinted polymers to sorb three fungicides. It shows that the imprinted polymer could be used as a preconcentration phase in a multiresidue analysis of fungicides in hydroalcoholic medium.

Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system

Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane.

The Potential Use of Raw and Deodorized Non-Conventional Protein Powder in Human Food

This study aimed to evaluate the potential use of a non-conventional protein source, a powder made from earthworms, as human food. Sensory analyses were done in order to assess the acceptability of cookies that were fortified with Eisenia foetida (Ef) protein powder. Cocoa and cinnamon were used as taste-masking agents. The acceptability of cookies fortified with deodorized Ef protein powder (off-flavor reduced) was also evaluated. We demonstrated that cocoa cookies can be fortified with 3.9% of raw Ef proteins and that cocoa/cinnamon cookies can be fortified with 5.2% of raw Ef proteins without any loss in their acceptability. Cookies fortified either with a raw protein powder or with a deodorized protein powder are significantly different up to a protein substitution level of 5%. Unflavored cookies can be fortified with 5.6% of deodorized Ef proteins and remain acceptable.

Identification of Key Gin Aroma Compounds: An Integrative Approach Based on an Original Selection Procedure

Potential impact aroma compounds of gin have been identified using Gas Chromatogry Olfactometry Mass-Spectrometry (GC-O-MS). In order to select some of them for a recombination study, we developed a specific procedure. Instead of only choosing the compounds on criteria such as their odor quality or their odor activity values, we also used physico-chemical parameters and information on their botanical origin. Data were organized in blocks homogeneous in terms of parameter type. Different statistical treatments were used in order to classify the compounds either by analyzing the parameters altogether or separately block by block.