Institute National Of Recherche Et Danalyse Physico Chimique Inrap

Sidi Bou Saïd, Tunisia

Institute National Of Recherche Et Danalyse Physico Chimique Inrap

Sidi Bou Saïd, Tunisia

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Hosni K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Msaada K.,Center de Biotechnologie de la Technopole de Borj-Cedria | Ben Taarit M.,Center de Biotechnologie de la Technopole de Borj-Cedria | Marzouk B.,Center de Biotechnologie de la Technopole de Borj-Cedria
Biochemical Systematics and Ecology | Year: 2011

The essential oils and phenolic constituents from the aerial parts of Hypericum triquetrifolium Turra, were analyzed at three developmental stages (vegetative, flowering and fruiting stages). The highest content of oil (0.12% w/w) was obtained at full flowering. Whatever the analyzed stage, n-octane, α-pinene, β-caryophyllene, 2-methyloctane, n-nonane, α-longipinene, caryophyllene oxide and β-pinene were found to be the main compounds. However, their percentages varied with the phenological cycle. Analysis by RP-HPLC-DAD of the methanolic extracts enabled us to identify 14 phenolic components and rutin, hyperoside, quercitrin and quercetin were reported as the main components. With the exception of chlorogenic acid, kaempferol and amentoflavone, the content of the remaining identified phenolic components varied with the phonological cycle. © 2011 Elsevier Ltd.


Maoulainine L.B.M.,University of Nouakchott | Jelassi A.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Hassen I.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Boukhari A.O.M.S.O.,University of Nouakchott
International Food Research Journal | Year: 2012

Sun spurge plants (Euphorbia helioscopia, L.) were collected from the north of Tunisia. Dried plant parts namely flowers, leaves and stem were individually extracted with methanol and ethanol. Extracts were screened for their antioxidant activity using the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical test. Total phenolics and total flavonoids amounts were also measured. The highest radical scanvenging effect was observed in flowers methanolic extract with IC 50 value of 26.66 ± 0.000μg/ml. While, relatively poorer antioxidant activity were observed in the same extracts of leaves and stem with respective IC 50 values of 65.25 ± 0.004 and 80.17± 0.012 μg/ml. The IC 50 values ranged from 27.55 ± 0.005 to 179.02 ± 0.957μg/ml in ethanol extracts of the above mentioned tested samples. Polyphenols and total flavonoids amounts varied in significant way among tested aerial parts of Euphorbia helioscopia and among two used solvents, the highest phenolics and flavonoids contents were found in methanolic flowers extracts (51.49 ± 0.012 mg GAE/g dry weights, 11.38 ± 0.004 mg QE/dry weight respectively). However, ethanol extract of stem gave the lowest amounts of total phenolics and flavonoids (4.80 ± 0.001 mg GAE/g dry weight and 1.69 ± 0.001 mg QE/dry weight respectively).


Hosni K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Hassen I.,Institute National Of Recherche Et Danalyse Physico Chimique | Sebei H.,Ecole Superieure dAgriculture de Mograne | Casabianca H.,CNRS Institute of Analytical Sciences
Industrial Crops and Products | Year: 2013

The essential oil of Chrysanthemum coronarium (Garland) flowerheads was analyzed by gas chromatography-mass spectrometry and essayed for its in vitro scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and its antimicrobial activities against Escherichia coli, Salmonella typhymurium, Candida albicans, Bacillus cereus and Staphylococcus aureus. The aqueous extracts were tested for their allelopathic properties on seed germination and seedling growth of two annual weeds (Sinapis arvensis and Phalaris canariensis) and two crops (Triticum durum and Zea mays) and the identity of the phenolic components was determined by using HPLC-PDA-MS. A total of 40 components, representing 96.58% of the total oil were identified, and the most plentiful constituents were found to be cis-chrysanthenyl acetate (21.82%), trans-chrysanthenyl acetate (12.78%), (E)-β-farnesene (8.97%), germacrene-D (8.92%) and camphor (6.03%). The oil was unable to reduce the DPPH radical, while it exhibited a good antimicrobial activity against the gram-positive bacteria B. aereus and S. aureus. The aqueous extracts suppress the germination and reduce the seedling growth of the target species. The phytotoxic effect was found to be selective towards weeds with the effects being more pronounced in S. arvensis and P. canariensis. HPLC-PDA-MS analysis allowed the identification of chlorogenic acid acid, di-cafeoylquinic acids isomers, rutin, luteolin, luteolin-7-O-glucoside, myricetin-3-O-galactoside and tricin. The latter components were reported in C. coronarium for the first time. It is suggested that the identified components may be at least, a key factors in the observed phytotoxic activity and the data presented may contribute to the development of naturally occurring herbicides. © 2012 Elsevier B.V.


Dziri S.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Hosni K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap
Acta Physiologiae Plantarum | Year: 2012

The effects of cement dust on the chemical composition of essential oil, lipid peroxidation and antioxidant enzyme activities of Aleppo pine (P. halepensis) needles were studied. Cement dust resulted in a significant decrease in the yield of essential oil with the effect being more pronounced in the close vicinity of the cement factory. A concomitant decrease in all components of the oil was observed and δ-2-carene, trans-carveol, trans-carvyl acetate, α-terpinyl acetate, β-copaene, (E,E)-α-farnesene, α-calacorene, α-cadinene, spathulenol, humulene oxide II, 8-epi-γ-eudesmol, Ί-muurolol, cubenol and ethyl hexadecanoate have been proposed as biological indicators of cement dust. Moreover, a redirection of the secondary metabolism toward the biosynthesis of monoterpenes has been evidenced. Malondialdehydes (MDA), a decomposition product of polyunsaturated fatty acids, often considered as a suitable biomarker for lipid peroxidation was induced in the needles exposed to cement dust. Similarly, a remarkable induction of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities was noticed. The positive relationships were observed among activities of antioxidant enzymes, and between MDA content and activities of antioxidant enzymes, indicating the cooperative action of these antioxidant enzymes to cope with the oxidative stress induced by cement dust. The results obtained indicate that P. halepensis needles are useful bio-monitors of cement dust pollution. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.


Khwaldia K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap
BioResources | Year: 2013

Hydroxypropyl methylcellulose (HPMC)-coated papers without plasticizer and plasticized with polyols were prepared, and the effects of coating weight, different plasticizers (glycerol (GLY), sorbitol (SOR), and polyethylene glycol (PEG)), and plasticizer contents (20% to 50%) on the physical and mechanical properties of the resulting biopolymer-coated papers were studied. Coating weight was the most important factor affecting mechanical properties. Conversely, increasing coating weight led to a decrease in gloss andto an increase in tensile strength (TS), elongation at break (%E), and tearing resistance of coated papers. The application of unplasticized HPMC coatings (3 g/m2) on paper reduced water vapor permeability (WVP) and water absorption capacity by 25% as compared with uncoated paper. All plasticizers significantly (p < 0.05) increased WVP and Cobb60 values of the films. With the exception of PEG, no effect was found with plasticizers on TS and %E ofcoated papers compared with those without plasticizer. HPMC-coated papers with PEG as a plasticizer showed significantly lower TS and higher %E and tearing resistance than the other plasticized films (p < 0.05). HPMC coating improved tensile properties and tearing resistance of paper and could be regarded as a reinforcement layer.


Khwaldia K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Basta A.H.,National Research Center of Egypt | Aloui H.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | El-Saied H.,National Research Center of Egypt
Carbohydrate Polymers | Year: 2014

Papers coated with caseinate and caseinate/chitosan bilayer films were developed. Caseinate, chitosan and caseinate/chitosan films were preliminary characterized by FTIR spectroscopy and thermal stability analyses. The effects of coating weight, caseinate concentration (7%, 10%, and 12%, w/w), and coating application methods (single layer and bilayer) on the physical and mechanical properties of coated papers were studied. Increasing the concentration of caseinate led to a decrease in water vapor permeability (WVP) of the resulting coated paper sheets. Chitosan significantly (p < 0.05) increased the elongation at break (%E) of coated paper. However, the application of chitosan as a second layer on wet or dry caseinate films did not significantly affect (p > 0.05) the tensile strength (TS) of coated paper. The greatest reduction in paper WVP is achieved by addition of a chitosan layer to the dried preformed caseinate-coated paper. © 2013 Elsevier Ltd. All rights reserved.


Aloui H.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Khwaldia K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Slama M.B.,CNRS Institute of Earth Sciences | Hamdi M.,CNRS Institute of Earth Sciences
Carbohydrate Polymers | Year: 2011

The effects of glycerol concentration and coating weight on biopolymer-coated paper properties were investigated using response surface methodology. Tests were run on the coated papers to determine water vapor barrier and mechanical properties. Coating weight was the most important parameter affecting water vapor permeability (WVP). Conversely, increasing coating weight led to a decrease in WVP and to an increase in tensile strength (TS) of the resulting coated papers. The papers coated with sodium caseinate (NaCAS) exhibited lower WVP values than those coated with other biopolymers. The TS of the papers coated with hydroxypropylmethylcellulose (HPMC) and chitosan was not affected by the glycerol concentration. HPMC-coated papers were higher in TS and %E than the other coated papers. For all types of coated paper, a maximum level of coating weight and level of glycerol concentration within range of 18.72-26.11% were found to be optimum for minimum WVP and maximum TS and %E. © 2011 Elsevier Ltd All rights reserved.


Aloui H.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Khwaldia K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap
Comprehensive Reviews in Food Science and Food Safety | Year: 2016

Natural antimicrobial agents have been investigated as alternatives to synthetic ones for ensuring food safety and quality. However, the practical use of these preservatives in the food industry is limited due to their negative impact on the odor and taste of food products, as well as the early loss of functionality due to their rapid diffusion and interaction with food components. The incorporation of natural antimicrobial agents into edible coatings has been investigated to control diffusion of active compounds and maintain their concentrations at a critical level on a food surface. Recently, nanoencapsulating and multilayered/nanolaminate delivery systems have emerged as promising tools to enhance the functionality of edible coatings. This review highlights the potential use of polymeric edible coatings for the incorporation of natural antimicrobial agents and the improvement of their controlled release in food systems. The methods used to assess the antimicrobial activity of encapsulated natural antimicrobial agents and the most recent findings regarding the application of nanoencapsulating and multilayered/nanolaminate delivery systems in food products are also discussed. © 2016 Institute of Food Technologists®


Aloui H.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Aloui H.,CNRS Institute of Earth Sciences | Khwaldia K.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Licciardello F.,University of Catania | And 4 more authors.
International Journal of Food Microbiology | Year: 2014

This study reports the efficacy of the combined application of chitosan (CH) and Locust Bean Gum (LBG) in combination with different citrus essential oils (EOs) to inhibit Aspergillus flavus in vitro and on artificially infected dates for a storage period of 12. days. The effect of these treatments on the fruits' sensory characteristics was evaluated to verify the complete absence of off-odours and off-flavours. Bergamot EO was the most effective in reducing mycelial growth, followed by bitter orange EO. Both bergamot and bitter orange oils significantly reduced conidial germination and a complete inhibition was obtained at concentrations higher than 2%. The mixtures based on CH-2% (v/v) bergamot EO or CH-2% (v/v) bitter orange EO proved to be the most effective coatings to reduce conidial germination resulting in an 87-90% inhibition compared with the control. In fruit decay assays coatings based on CH incorporating citrus oils were able to reduce fungal decay in the range of 52-62% at day 12.The study results and the complete absence of off-flavours and off-odours demonstrate the potential of CH coatings carrying citrus EOs at sub-inhibitory concentrations to control postharvest growth of A. flavus in dates. © 2013 Elsevier B.V.


Zarrougui R.,Institute National Of Recherche Et Danalyse Physico Chimique Inrap | Zarrougui R.,Tunis el Manar University | Raouafi N.,Tunis el Manar University | Lemordant D.,University of Tours
Journal of Chemical and Engineering Data | Year: 2014

A new series of 12 cyclic ammonium-based room temperature ionic liquids (RTILs) containing an alkylphosphite anion have been synthesized by an alkylation reaction between cyclic tertiary amines and dialkylphosphite. This method constitutes an eco-friendly pathway to RTILs that does not generate any secondary byproducts and avoiding the metathesis reaction involving uses of nonfriendly or expensive salts. Their physicochemical and electrochemical properties have been investigated. The temperature dependency of density, dynamic viscosity, and ionic conductivity were determined at temperatures varying from 293.15 to 323.15 K and were discussed on a structural basis. For the prepared RTILs, the viscosity values are fairly high and low ionic conductivity as compared to usual ILs. The transport properties were found to be temperature-dependent and followed the Arrhenius law. The RTILs potential windows (δE) are comprised between 3.00 and 4.77 V. The electrochemical stability seems to be influenced by the alkyl side chain. An increasing in the carbon number of the cation and anion side chain decreases the electrochemical window of RTILs. The correlation between ionic conductivity and viscosity was studied on the basis of the Walden rule, and the new RTILs can be classified as associated ionic liquids (AILs), an intermediate between a true, ionic liquid and a molecular species. © 2014 American Chemical Society.

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