Antioxidant properties of ethanol waste extracts from olive industry. Catamarca ?Argentina

GÓMEZ, PATRICIA; SALIM ROSALES, CLAUDIA; GÓMEZ, ELIZABETH; RODRÍGUEZ, NORMA; BRAVO, MARÍA

Chania- Crete

Conferencia; 4° Conference on Biothecnology and Olive Products Quality in the Mediterranean- OLIVEBIOTEQ 2011; 2011

National Agricultural Research Foundation (NAGREF)- Institute of Olive Tree and Subtropical Plants

Olive industry generates, apart from olive oil, agro-industrial residuals mainly alperujo and pruning waste. These are more and more abundant and have a rich potential in antioxidants which is still wasted. Antioxidant activity as inhibitors of the biomolecule oxidation and the importance of its application in food industries, pharmacology and cosmetology has largely spread. On the other hand, several research works demonstrate antioxidant presence, mainly polyphenols, in different organs of the olive tree. This work aims at evaluating not only the potentiality of alperujo and pruning waste as source of natural antioxidants but also the antioxidant properties of their ethanol extracts in olive trees, Arbequina variety, coming from the Central Valley of the province of Catamarca. Ethanol extracts from alperujo, from olive leaves and from olive tree wood were obtained by soaking. Their phenolic content was evaluated, by means of the Folin-Ciocalteu method. The antioxidant activity was analyzed by putting the extracts on virgin olive oil. In the case of leaf extracts and olive tree wood, the anti-radical capacity was also measured, using a test with the radical 2,2-difenil-1-picrilhidracilo (DPPH). Arbequina leaves showed a better ethanol yield in phenols than the tree wood and this, in turn, a better yield than the alperujo. However, the three materials are positioned in advantage in front of other vegetable sources. The difference of the extractive power of the ethanol could be related to a difference in polarity of phenols in waste. The alperujo extract incorporated to the lipid substrate in a higher proportion than the leaf and wooden extracts. The acidic profile did not prove modification with the application of both treatments. The alperujo extract incorporated products of primary and secondary oxidation. The wooden extract showed higher antioxidant activity on the applied lipid matrix since it is the one that reduced in more percentage to the IP, evidencing a light protective effect. Pruning extracts presented a high capacity to capture free radicals DPPH. The obtained results indicate the possibility of considering olive industry waste as by-products and sub-products to isolate phenolic extracts and pure compounds with antioxidant activity, a fact that would contribute to avoid environmental problems and to grant profitability to a totally wasted material.