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Tlili N.,Tunis el Manar University | Elfalleh W.,Institute Des Regions Arides Of Medenine | Hannachi H.,Institute Des Regions Arides Of Medenine | Yahia Y.,Institute Des Regions Arides Of Medenine | And 3 more authors.
International Journal of Food Properties | Year: 2013

Medicinal plants contain high levels of natural antioxidants and exhibited strong antioxidant activity. In order to find new sources of natural antioxidants, a screening of natural antioxidants from some Tunisian medicinal plants commonly associated with treatment of some diseases were conducted. The total phenolic compounds, flavonoids, anthocyanins, and hydrolysables tannins were measured, and the antioxidant capacities were evaluated using DPPH and Trolox equivalent antioxidant capacity assays. Results prove that there are important quantities of these compounds in Tunisian medicinal plants. A positive linear correlation between Trolox equivalent antioxidant capacity and the phenolic compound contents suggested that these compounds were a major contributor of antioxidant activity of these plants. The results from this study will help us understand the antioxidant capacity profiles of these medicinal plants, and also investigate new sources of natural antioxidants. Copyright © 2013 Taylor & Francis Group, LLC.

Nasri N.,University of Tunis | Elfalleh W.,Institute des Regions Arides | Tlili N.,University of Tunis | Martine L.,University of Burgundy | And 4 more authors.
JAOCS, Journal of the American Oil Chemists' Society | Year: 2013

Seeds from 12 Acacia cyanophylla ecotypes, harvested in Tunisia, were examined for their seed oil contents of carotenoids, tocopherols and phytosterols. The average carotenoid content (lutein and zeaxanthin) was ca. 102 mg kg-1 of total extracted lipids. Lutein (ca. 97 mg kg-1 of total extracted lipids) was usually more abundant than zeaxanthin (ca. 5 mg kg-1 of total extracted lipids). The mean total tocopherol content was ca. 704 mg kg-1 of total extracted lipids. The main isomer was α-tocopherol, with more than 75 % of total tocopherols (ca. 528 mg kg -1 of total extracted lipids), followed by γ-tocopherol (ca. 168 mg kg-1 of total extracted lipids) and δ-tocopherol (ca. 86 mg kg-1 of total lipids). High levels of phytosterols (ca. 7.8 g kg-1 of total extracted lipids) were detected, among which β-sitosterol was the most abundant (47 %). All these results highlight the richness of carotenoids, tocopherols and sterols in A. cyanophylla seed oil, and imply that this species might constitute a potential resource for the development of functional foods. © 2012 AOCS.

Hannachi H.,Laboratoire dAridoculture et cultures oasiennes | Elfalleh W.,Laboratoire dAridoculture et cultures oasiennes | Ennajeh I.,Laboratoire dAridoculture et cultures oasiennes | Laajel M.,Laboratoire dAridoculture et cultures oasiennes | And 4 more authors.
Journal of Medicinal Plant Research | Year: 2011

This study reported investigations on phytochemical screening and antioxidants activities of seeds from seven Acacia species. Storage proteins and mineral contents were determined. The seed extracts of Acacia species were evaluated for their total phenols, flavonoids, carotenoids contents and total antioxidant capacity assessed by 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2- diphenyl-1- picrylhydrazyl (DPPH) assays. Total protein content ranged from 99.49 (Acacia cyclops) to 142.77 (Acacia cyanaphylla) mg/g dry weight basis (DW) according to the Acacia species, having an average of 120.41 mg/g DW. The albumin constitutes the major fraction presenting 31.11%, followed by globulin (27.36%), prolamin (22.27%) and glutelin (19.27%). The Acacia seeds were rich in minerals. The total phenolic compounds (TPC) determinate ranged from 154.47 (A. cyclops) to 1217.99 (Acacia horrida) with an average of 632.40 mg gallic acid equivalents/100 g DW. The total flavonoid contents have an average of 11.21 mg rutin equivalents/100 g DW, and the carotenoids mean is 4.23 mg/kg. The Acacia seed extracts have an antioxidant activity reflected by the ABTS and DPPH tests. The Duncan's test showed significant difference of proteinic, phenolics, flavonoid and carotenoid contents according to the Acacia species. Therefore, natural components from Acacia seeds could be incorporated as food ingredient, without causing detrimental effects to the food's palatability and the functional ingredient's efficacy. © 2011 Academic Journals.

Ghazghazi H.,Institute National Dagronomie Of Tunis | Miguel M.G.,University of Algarve | Miguel M.G.,University of Lisbon | Hasnaoui B.,Institute Sylvo Pastoral | And 5 more authors.
African Journal of Biotechnology | Year: 2010

The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in those samples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of β-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity. © 2010 Academic Journals.

Youzbachi N.,University of Tunis | Elfalleh W.,Laboratoire dAridoculture et des Cultures Oasiennes | Tlili N.,University of Tunis | Gregoire S.,French National Institute for Agricultural Research | And 7 more authors.
Journal of the Science of Food and Agriculture | Year: 2012

Background: In order to investigate new sources of dietary phytochemicals, recent studies have focused on underexploited seeds. In this study the total lipid contents, fatty acid profiles and levels of soluble proteins, minerals and antioxidants in seeds from 12 Acacia cyanophylla ecotypes commonly grown in Tunisia were determined. Results: Total lipids averaged 101.7 g kg -1 on a dry weight basis. Linoleic (61.11-65.45% of total fatty acid content), oleic (19.67-22.85%) and palmitic (9.18-9.98%) acids were the principal fatty acids. Smaller proportions of stearic (1.49-1.82%), vaccenic (1.13-2.05%) and palmitoleic (0.34-0.58%) acids were also quantified. Proteins (by Kjeldahl assay) averaged 107.2 g kg -1 on a dry weight basis. Total phenolics averaged 1.91 g gallic acid equivalent kg -1 dry weight (DW) and total flavonoids averaged 0.40 g rutin equivalent kg -1 DW. The free radical-scavenging activity determined by 2,2-diphenyl-1-picrylhydrazyl assay averaged 0.59 mmol L -1 Trolox equivalent antioxidant capacity (TEAC), while that determined by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay averaged 0.28 mmol L -1 TEAC. Conclusion: The findings of this study confirm the presence of ω6 fatty acids at high levels in A. cyanophylla seeds. These metabolites could be used as such and/or extracted for the formulation of supplements and/or ingredients to provide a ratio close to the ideal for the ω3/ω6 balance. © 2012 Society of Chemical Industry.

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