Comparative study of total phenolic content and antioxidant properties of Quercus fruit: flour and oil
Open Access
- 5 March 2019
- journal article
- Published by The North African Journal of Food and Nutrition Research (NAJFNR) in The North African Journal of Food and Nutrition Research
Abstract
Aim: The current study was undertaken to determine the total phenolic and flavonoid contents and to assess the antioxidant activity of two different extracts (flour and oil) of two Algerian Quercus species, Quercus ilex L. and Quercus suber L. Methods and Material: The oil extraction of the two species was achieved using the Soxhlet method. The obtained extracts were estimated for the chemical and physical constants (acidity, peroxide value, iodine value, and ultraviolet absorption indices). Total phenolic content was measured by spectrophotometry according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). The studied extracts were submitted to an estimation of their flavonoid contents too, using aluminum chloride methods. Antioxidant ability was assessed by means of two distinct methods (DPPH• and ABTS•+). Results: The obtained results revealed that antioxidant properties, total phenolic, and total flavonoid contents differed significantly among selected species and extracts. The flour samples possessed the highest level of total phenolic contents (1101–1464 mg GAE/kg dry weight) and exhibited the highest antioxidant capacities with average values of 52.62–40.78 μmol TE g−1 dry weight and 36.19–44.50 μmol TE g−1 dry weight for DPPH and ABTS assays, respectively. Acorn oil extracts showed also remarkable antioxidant activity, up to 2.69 and 3.23 μmol TE g−1 oil (DPPH and ABTS test, respectively), even though the total phenolic contents were low (195.64–322.06 mg GAE /kg of oil). Total phenolic amounts were positively correlated with the antioxidant properties of Quercus flour and oil. Conclusions: Our study provides basic information on the presence of bioactive compounds and antioxidant capacity in acorn fruits, in order to consider their extracts as functional food ingredients and potential source of natural antioxidants. Keywords: Quercus ilex L., Quercus suber L., Total phenolic, Total flavonoid, Antioxidant activity.Keywords
This publication has 44 references indexed in Scilit:
- Espèces réactives de l’oxygène et stress oxydantmédecine/sciences, 2011
- Acorns (Quercus rotundifolia Lam.) and grass as natural sources of antioxidants and fatty acids in the “montanera” feeding of Iberian pig: Intra- and inter-annual variationsFood Chemistry, 2011
- ABCG2 reduces ROS‐mediated toxicity and inflammation: a potential role in Alzheimer’s diseaseJournal of Neurochemistry, 2010
- Flavanols and Anthocyanins in Cardiovascular Health: A Review of Current EvidenceInternational Journal of Molecular Sciences, 2010
- Polyphenolic content and in vitro antioxidant characteristics of wine industry and other agri-food solid waste extractsJournal of Food Composition and Analysis, 2007
- Effect of Extraction Conditions on Measured Total Polyphenol Contents and Antioxidant and Antibacterial Activities of Black TeaMolecules, 2007
- Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancerLife Sciences, 2004
- Polyph nols v g taux, sources, utilisations et potentiel dans la lutte contre le stress oxydatifPhytotherapie, 2004
- Oils and fats manual: A comprehensive treatise — properties, production, application. Edited by A. Karleskind and J.‐P. Wolff. 1527 pages. TEC & DOC Lavoisier, France, 1996, Price 465 US$, 2189 FF. ISBN 1‐898298‐08‐4. (French language version ISBN 2‐852066‐62‐9)Chemische Umschau auf dem Gebiet der Fette, Oele, Wachse und Harze, 1997
- Official Methods and Recommended Practices of the American Oil Chemist's Society, Physical and Chemical Characteristics of Oils, Fats and Waxes, Section I. Ed. The AOCS Methods Editor and the AOCS Technical Department. 54 pages. AOCS Press, Champaign, 1996Chemische Umschau auf dem Gebiet der Fette, Oele, Wachse und Harze, 1997