This project has been funded with support from the European Commission.This poster reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.

Optimisation of phenolic compounds extraction from grape pomace using Accelerated solvent extraction ASE

Industry request: Antioxidant phenolic compounds to be used in cosmetics , pharmaceuticals, nutraceuticals to enhance health properties and attractive red

MENA Supervisor:Pr. Richard MarounSaint-Joseph University MENA Student:Hiba Rajha

European Supervisor:Mag. Dr. Herbert BöchzeltJoanneum Research

European Student:Walter Ziegler, Bakk.rer.nat.

3. Optimisation of different parameters After finding the best Temperature and solvent the efficiency of ASE was determined at different static times : 0 , 5 and 10 minutes (Fig. 2) and the effect of filtration was studied (Fig. 3).

Fig.1.: Quantification phenolic compounds by Folin Ciocalteau method in extracts obtained by different extraction parameters ( solvent , temperature)

Fig.2.: Variation of the extracts concentration with different static times using folin-ciocalteau method

IntroductionIn the past few years there has been an increasing interest in determining relevant dietary sources of antioxidant phenolics. Grape (Vitis vinifera) is among the fruits with the highest content of these compounds. A large amount of different phenolic compounds is present in skin, pulp and seeds, and they also undergo partial extraction during winemaking processes (Revilla and Ryan, 2000), and Because world population is in continuous growth and natural resources are consequently limited, studies dealing with the utilization of renewable sources and the design of processes based on the integral exploitation of natural products have attracted great interest in the past several years. The recovery of grape byproducts from agricultural industries to be converted into value-added products is a good example to benefit not only from antioxidant properties of its phenolic compounds but also reducing the amount of waste

4. The left to be doneIn order to complete the study, the extracts will be transported to the laboratory of the Faculty of sciences at Saint Joseph University Beirut-Lebanon where the quantification of the Total Phenolic Compounds (TPC) (using the Folin- Ciocalteau method), their quality ( using DPPH assays and the capacity of the extract on protecting DNA against peroxyde degradation) and their characterization by HPLC will be assessed. Finally the possibility of the extracts contamination with bacteria and mycotoxins (aflatoxin and ochratoxin) will be ruled out using ELISA kits.

Conclusions•70% Ethanol at 140°C and for 10 minutes static time in accelerated solvent extraction (ASE) are the best conditions for phenolic compounds extraction from grape pomace.•Filtration of the extract results in a loss up to 40% of the phenolic compounds. •These findings could be the basis of an industrial process development for the valorization of wine industries waste.

Experiments and Results

1.Objective The aim of the study is to Extract the maximum quantity with the best quality of

phenolic compounds out of grape by-products/pomace using Accelerated Solvent Extraction (ASE), in order to valorize this waste. The extracted molecules (phenolic compounds) will be used as bioactive compounds in cosmetics , food conservation, nutraceuticals, etc..

2. ExtractionIn the Joanneum Research laboratory in Graz the Accelerated Solvent Extraction

ASE assays were realized in presence of ethanol/water mixtures of 30, 50, 70 and 90% (v/v) , at different Temperatures (40, 60, 80, 100, 120 and 140 °C) , at a fixed pressure (100 bars) and fixed time (static time = 0 minutes). A quantification was also made using Folin-Ciocalteau method (Fig. 1) and IPT (total phenolic compounds index) in order to determine the optimal temperature and ethanol mixture.

Fig.3.: Variation of the extracts concentration using folin ciocalteau method before and after filtration

The extraction process was optimized on a small scale study (using arround 38 g of raw material/extraction) using ASE method , in order to be compromised to fit a larger industrial scale extraction a trial was conducted at the Joanneum Research laboratories in Hartberg. During this assay phenolic compounds were extracted using around 5 kg of raw material per extraction. A comparative study of the results obtained using ASE and those of the industrial extraction unit could give us a clear idea about the overall optimization process.

Fig.5.: Total extracted compounds with 70% EtOH at different extraction temperatures

Fig.4.: Total extracted compounds (mg/g dry matter pomace) with 70%EtOH/60°C