Time filter

Source Type

Yeddes N.,Laboratoire Dapplication Of La Chimie | Cherif J.K.,Laboratoire Dapplication Of La Chimie | Cherif J.K.,Institute Preparatoire Aux Etudes Dingenieurs Of Tunis Ipeit | Ayadi M.T.,Laboratoire Dapplication Of La Chimie
Pakistan Journal of Biological Sciences

The antioxidant activity and the chemical composition of methanol extracts from peel and pulp belonging to two species of Tunisian prickly pears Opuntia ficus indica (spiny and thornless forms) and Opuntia stricta has been studied. The antioxidant capacity was measured by DPPH radical scavenging activity. The Total Phenolic Compound (TPC) and the total flavonoid content were determined by the Folin-Ciocalteu method and colorimetric method, respectively. The phenolic compounds were identified and quantified by High Performance Liquid Chromatography (HPLC) coupled with an electrospray ionization mass spectrometry (ESI-MS). The results showed that O. stricta fruits present the best antioxidant activities than the two forms of O. ficus indica while the TPC was more important in O. ficus indica than in the O. stricta fruits. The peels have higher flavonoids than pulps and the thornless has more flavonoid than the spiny. The RP-HPLC and ESI-MS analysis detected two classes of phenolic compounds and betalain pigments. Isorhamnetin derivatives are the dominant flavonol glycoside identified in O. ficus indica (spiny: 65.25 jag g-1; thornless: 77.03 jag g-1) and O. stricta peels (19.22 jag g-1). © 2014 Asian Network for Scientific Information. Source

Mraihi F.,University of Carthage | Hidalgo M.,Institute of Food Science and Technology and Nutrition ICTAN CSIC | de Pascual-Teresa S.,Institute of Food Science and Technology and Nutrition ICTAN CSIC | Trabelsi-Ayadi M.,University of Carthage | And 2 more authors.
Arabian Journal of Chemistry

Hawthorn fruits (Crataegus spp.), may be a good source of antioxidants if is consumed as fresh fruit since we know that it produce a numerous beneficial effects for human health. In this study, two species of hawthorn fruit, Crataegus monogyna and Crataegus azarolus were analyzed by HPLC-DAD-MS and compared with respect to their phytochemical composition. Phenolic profiles of studied fruits showed some similarities and differences in terms of polyphenols between the two species. Twenty phenolics compounds distributed into four subclasses were identified: four phenolic acids including three hydroxycinnamic acids and one hydroxybenzoic acid, eight flavonoids representing the most abundant subclass including six glucosylated flavonols and two flavones, two anthocyanins are present as glycosides of cyanidin, with cyanidin-3-. O-glucoside is the most abundant, only in monogyna peel fraction and four flavanols divided into a monomer (-)-epicatechin identified in all fruit parts of both species, a dimer B2 and two trimers (C1 and C2). These phenolic compounds are concentrated especially in peel fraction. These results indicate that hawthorn fruits should be recommended in dietary habits as a potential source of antioxidant and anticarcinogenic phenolic compounds. © 2014 The Authors. Source

Hammouda H.,University of Carthage | Hammouda H.,French National Institute for Agricultural Research | Kalthoum Cherif J.,University of Carthage | Kalthoum Cherif J.,Institute Preparatoire Aux Etudes Dingenieurs Of Tunis Ipeit | And 3 more authors.
Italian Journal of Food Science

Six varieties of Tunisian apples were studied on the basis of their detailed polyphenol profiles. Reversed Phase High performance Liquid Chromatography (RP-HPLC) was used to separate and identify the compounds. Thiolysis coupled to RP-HPLC was used to determine the nature and the proportion of the constitutive units as well as the concentration of procyanidins. The structural analysis of some phenolic compounds was carried out using an ion trap mass spectrometer equipped with an electrospray source (LC-ESI-MS) used in negative mode. the total antioxidant capacity was determined using the FRAP method. Source

Mraihi F.,University of Carthage | Journi M.,University of Carthage | Cherif J.K.,University of Carthage | Cherif J.K.,Institute Preparatoire Aux Etudes Dingenieurs Of Tunis Ipeit | And 3 more authors.
Journal of Chemistry

Crataegus fruit is one of most important fruits in Tunisian flora. Some fruits of this genus are edible. This study was undertaken in order to examine the benefits of these fruits in human health and their composition of antioxidants including total polyphenol, flavonoids, proanthocyanidins content, and total anthocyanins. The antioxidative properties of the ultrasonic methanolic extract were assessed by different in vitro methods such as the FRAP, DPPH, and β-carotene/linoleic acid assay. We concluded that peel fraction of red fruits possessed relatively high antioxidant activity and might be a rich source of natural antioxidants in comparison with the pulp and seed fruit extract. The results also showed that hawthorn yellow fruit presents lower amounts of phenolic content, absence of anthocyanins, and less antioxidant capacity. Most of peel and seed fractions were stronger than the pulp fractions in antioxidant activity based on their DPPH IC50, FRAP values, and results of β-carotene/linoleic acid. The total phenolic compounds contents were also highly correlated with the DPPH method and the FRAP assay. © 2013 Farouk Mraihi et al. Source

Hammouda H.,University of Carthage | Hammouda H.,French National Institute for Agricultural Research | Alvarado C.,French National Institute for Agricultural Research | Bouchet B.,French National Institute for Agricultural Research | And 4 more authors.
Journal of Agricultural and Food Chemistry

A histological approach including light microscopy and transmission electron microscopy (TEM) was used to provide accurate information on the localization of condensed tannins in the edible tissues and in the stone of date fruits (Phoenix dactylifera L.). Light microscopy was carried out on fresh tissues after staining by 4-dimethylaminocinnamaldehyde (DMACA) for a specific detection of condensed tannins. Thus, whether under light microscopy or transmission electron microscopy (TEM), results showed that tannins are not located in the epidermis but more deeply in the mesocarp in the vacuole of very large cells. Regarding the stones, tannins are found in a specific cell layer located at 50 μm from the sclereid cells of the testa. © 2014 American Chemical Society. Source

Discover hidden collaborations