![Antioxidant activity
Abstract
In recent years, studies on the extraction of phenolic compounds from natural products have attracted special attention. Phenols, potent antioxidants, are ubiquitous in
vegetables and have demonstrated an active role in preventing the progress of certain degenerative diseases. These beneficial effects have been partially attributed to the
compounds which possess antioxidant activity, mainly phenolic compounds [1]. Thus, the extraction of phenolic compounds from plant materials seems to be a very
interesting area of research, because it will allow industries to enhance the phenolic content of commercial products obtained from vegetables. The principal aim of this
work was to investigate the influence of the extraction conditions on the yield of phenolic compounds and the corresponding antioxidant capacity. The extracts obtained in
each experimental condition were analysed in terms of total phenolic content (TPC) by the Folin-Ciocalteau method and the antiradical power evaluated by the DPPH and
the ferric reducing antioxidant potential (FRAP) assay [2].
www.fc.up.pt/quaqua
Total phenolic content
Figure 1 – Evaluation of TPC, assessed by FC method, for the obtained extracts of broccoli and
lamb’s lettuce (mgGAE /100gsample).
Conclusions
o In the case of lamb lettuce, the extraction technique (stirring) and type of solvent (methanol) were found to have a critical role in the extraction of antioxidant
compounds;
o For broccoli extracts, yield was maximized for the total phenolic content when soxhlet extraction and water was used;
o The results showed that lamb lettuce, compared to broccoli, contain higher amount of total polyphenols (TPC) as well as higher antioxidant capacity measured by
both methods.
References
[1] D. Moreno, S. Pérez-Balibrea, F. Federico, A. Gil-Izquierdo, C. García-Viguera, Food Chemistry, 2010, 123, 358-
363.
[2] M. Dvorakova, M. Moreira, P. Dostalek, Z. Skulilova, L. Guido and A. Barros, Journal of Chromatography A, 2008,
1189, 398.
0
20
40
60
80
100
120
Ultrasound Gyratory
shaker
Ultrasound Gyratory
shaker
Soxhlet
Acetone Methanol Water
%ARP
Broccoli
Lamb's lettuce
Figure 2 – Antiradical power (ARP), evaluated by the DPPH method , for
the obtained extracts of broccoli and lamb’s lettuce (%).
Figure 3 – Antioxidant activity evaluated by the FRAP method, for the
obtained extracts of broccoli and lamb’s lettuce (mgTE /100gsample).
Acknowledgements
Manuela M. Moreira wishes to acknowledge Fundação para a Ciência e a Tecnologia (FCT) for her Ph.D. studentship
(SFRH/BD/36791/2009).
Future work
Work is in progress in order to characterize the phenolic profile and to
identify by HPLC-ESI-MS the phenolic compounds contributing to the
antioxidant capacity of the broccoli and lamb lettuce extracts.
Antioxidant activity
catarinapparente@hotmail.com
Antioxidants from broccoli and lamb’s lettuce: Influence of the extraction procedure on total phenolics
and antioxidant capacity
aREQUIMTE – Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
bEscola Superior Agrária de Viseu, Quinta da Alagoa - Estrada de Nelas, Ranhados, 3500-606 Viseu, Portugal
Catarina Parentea,b, Manuela M. Moreiraa, Maria J. Limab, Edite Teixeira-Lemosb, Aquiles A. Barrosa and Luís F. Guidoa
Experimental Procedure
Broccoli and lamb’s lettuce extractions are described in the scheme
1.
5 g of broccoli
or lamb’s
lettuce + 50 mL
solvent
(methanol or
acetone)
1 hour, 250 rpm
5 g of broccoli
or lamb’s
lettuce + 50 mL
solvent
(methanol or
acetone)
1 hour, 40 kHz
5 g of broccoli
or lamb’s
lettuce + 150
mL of water
4 hours
Gyratory shaker Ultrasound Soxhlet
Scheme 1 – Outline of the extraction procedure tested
0
50
100
150
200
250
300
Ultrasound Gyratory shaker Ultrasound Gyratory shaker Soxhlet
Acetone Methanol Water
mgGAE/100gsample
Broccoli
Lamb's lettuce
0
50
100
150
200
250
300
350
400
450
Ultrasound Gyratory
shaker
Ultrasound Gyratory
shaker
Soxhlet
Acetone Methanol Water
mgTE/100gsample
Broccoli
Lamb's lettuce
IJUP 2011](https://image.slidesharecdn.com/47ee614b-5f78-4e0d-a2f4-bec824376f12-150501133602-conversion-gate02/85/Poster_IJUP_2011_Catarina-1-320.jpg)
Poster_IJUP_2011_Catarina
- 1. Antioxidant activity Abstract In recent years, studies on the extraction of phenolic compounds from natural products have attracted special attention. Phenols, potent antioxidants, are ubiquitous in vegetables and have demonstrated an active role in preventing the progress of certain degenerative diseases. These beneficial effects have been partially attributed to the compounds which possess antioxidant activity, mainly phenolic compounds [1]. Thus, the extraction of phenolic compounds from plant materials seems to be a very interesting area of research, because it will allow industries to enhance the phenolic content of commercial products obtained from vegetables. The principal aim of this work was to investigate the influence of the extraction conditions on the yield of phenolic compounds and the corresponding antioxidant capacity. The extracts obtained in each experimental condition were analysed in terms of total phenolic content (TPC) by the Folin-Ciocalteau method and the antiradical power evaluated by the DPPH and the ferric reducing antioxidant potential (FRAP) assay [2]. www.fc.up.pt/quaqua Total phenolic content Figure 1 – Evaluation of TPC, assessed by FC method, for the obtained extracts of broccoli and lamb’s lettuce (mgGAE /100gsample). Conclusions o In the case of lamb lettuce, the extraction technique (stirring) and type of solvent (methanol) were found to have a critical role in the extraction of antioxidant compounds; o For broccoli extracts, yield was maximized for the total phenolic content when soxhlet extraction and water was used; o The results showed that lamb lettuce, compared to broccoli, contain higher amount of total polyphenols (TPC) as well as higher antioxidant capacity measured by both methods. References [1] D. Moreno, S. Pérez-Balibrea, F. Federico, A. Gil-Izquierdo, C. García-Viguera, Food Chemistry, 2010, 123, 358- 363. [2] M. Dvorakova, M. Moreira, P. Dostalek, Z. Skulilova, L. Guido and A. Barros, Journal of Chromatography A, 2008, 1189, 398. 0 20 40 60 80 100 120 Ultrasound Gyratory shaker Ultrasound Gyratory shaker Soxhlet Acetone Methanol Water %ARP Broccoli Lamb's lettuce Figure 2 – Antiradical power (ARP), evaluated by the DPPH method , for the obtained extracts of broccoli and lamb’s lettuce (%). Figure 3 – Antioxidant activity evaluated by the FRAP method, for the obtained extracts of broccoli and lamb’s lettuce (mgTE /100gsample). Acknowledgements Manuela M. Moreira wishes to acknowledge Fundação para a Ciência e a Tecnologia (FCT) for her Ph.D. studentship (SFRH/BD/36791/2009). Future work Work is in progress in order to characterize the phenolic profile and to identify by HPLC-ESI-MS the phenolic compounds contributing to the antioxidant capacity of the broccoli and lamb lettuce extracts. Antioxidant activity [email protected] Antioxidants from broccoli and lamb’s lettuce: Influence of the extraction procedure on total phenolics and antioxidant capacity aREQUIMTE – Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal bEscola Superior Agrária de Viseu, Quinta da Alagoa - Estrada de Nelas, Ranhados, 3500-606 Viseu, Portugal Catarina Parentea,b, Manuela M. Moreiraa, Maria J. Limab, Edite Teixeira-Lemosb, Aquiles A. Barrosa and Luís F. Guidoa Experimental Procedure Broccoli and lamb’s lettuce extractions are described in the scheme 1. 5 g of broccoli or lamb’s lettuce + 50 mL solvent (methanol or acetone) 1 hour, 250 rpm 5 g of broccoli or lamb’s lettuce + 50 mL solvent (methanol or acetone) 1 hour, 40 kHz 5 g of broccoli or lamb’s lettuce + 150 mL of water 4 hours Gyratory shaker Ultrasound Soxhlet Scheme 1 – Outline of the extraction procedure tested 0 50 100 150 200 250 300 Ultrasound Gyratory shaker Ultrasound Gyratory shaker Soxhlet Acetone Methanol Water mgGAE/100gsample Broccoli Lamb's lettuce 0 50 100 150 200 250 300 350 400 450 Ultrasound Gyratory shaker Ultrasound Gyratory shaker Soxhlet Acetone Methanol Water mgTE/100gsample Broccoli Lamb's lettuce IJUP 2011