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
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).
Effect of the filtration of the extracts at 2 different
Temperatures (80, 140 °C) on the phenolic
compound content determined by Folin-Ciocalteau
15000
(70% EtOH)
Concentration of extracts at 70% EtOH - 100 °C
with different Static times (0, 5 and 10 minutes)
9000
8500
8000
Concentration (GAE) [mg/L]
In 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
concentration (GAE) [mg/L]
Introduction
7500
7000
6500
6000
5500
5000
0
2
4
6
8
10
11000
10000
9000
Folin with filtration
Folin without filtration
8000
7000
60
80
100
120
140
160
Temperature [°C]
Fig.3.: Variation of the extracts concentration
using folin ciocalteau method before and
after filtration
total extracted compounds
[mg/g dry matter pomace]
200
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. Extraction
In 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.
Variation of the phenolic compounds content in the extract in
function of the solvent type and the Temperature
9000
30% Ethanol
8000
Concentration (GAE) [mg/L]
12000
Static Time (min)
1.Objective
10000
13000
6000
12
Fig.2.: Variation of the extracts concentration
with different static times using folinciocalteau method
Experiments and Results
14000
50% Ethanol
70% Ethanol
7000
90% Ethanol
6000
180
160
140
120
100
80
20
40
60
80
100
120
140
160
Temperature [°C]
Fig.4.: Total extracted compounds (mg/g
dry matter pomace) with 70%EtOH/60°C
Fig.5.: Total extracted compounds with 70%
EtOH at different extraction temperatures
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.
4. The left to be done
In 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.
5000
4000
3000
Conclusions
2000
1000
0
0
20
40
60
80
100
120
140
160
Temperature [°C]
Fig.1.: Quantification phenolic compounds by Folin Ciocalteau method in extracts
obtained by different extraction parameters ( solvent , temperature)
•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.
MENA Supervisor:
Pr. Richard Maroun
Saint-Joseph University
European Supervisor:
Mag. Dr. Herbert Böchzelt
Joanneum Research
MENA Student:
Hiba Rajha
European Student:
Walter Ziegler, Bakk.rer.nat.
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.