References of "Attia, Hamadi"
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See detailGamma radiation induced modifications of tapioca starch
Atrous, Hager; Benbettaïeb, Nasreddine; Hosni, Faouzi et al

in Asian Academic Research Journal of Multidisciplinary (2016), 3(3), 187-220

The effect of gamma radiation (3, 5, 10, 20, 35 and 50 kGy) on the morphological, structural, physicochemical, pasting and thermal properties of tapioca starch was studied. Microphotographs of scanning ... [more ▼]

The effect of gamma radiation (3, 5, 10, 20, 35 and 50 kGy) on the morphological, structural, physicochemical, pasting and thermal properties of tapioca starch was studied. Microphotographs of scanning electron microscopy and polarized light microscopy revealed the absence of morphological changes induced by gamma radiation. The X-ray diffraction spectra showed that irradiation treatment did not influence the shape and intensity of X-ray diffraction peaks. The presence of free radicals in the irradiated tapioca starch was confirmed by electron spin resonance spectrometry. Fourier transform infrared spectroscopy showed that the irradiated starch displayed a significant decrease in the intensity of the O–H and C–H stretches, bending modes of water and glycosidic linkages. Irradiation improved the water solubility index of starch granules and depressed the apparent amylose content. An increase in the swelling power was observed after irradiation treatment until 20 kGy, followed by a decrease at higher doses. Brabender viscoamylograph test showed that the maximal consistency of the starch paste decreased significantly with increasing irradiation dose. There was no significant difference in the gelatinization temperatures, as well as the corresponding transition enthalpies among native and irradiated tapioca starch samples, as shown in the differential scanning calorimetry thermograms. [less ▲]

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See detailEffect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps
Makhlouf-Gafsi, Ines; Baklouti, Samia; Mokni, Abir et al

in Food Chemistry (2016), 203

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied ... [more ▼]

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n = 0.783) to Newtonian behaviour (n〰1) from 10 to 50 s‾1 respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50 s 1). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups. [less ▲]

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See detailPhysico-chemical properties and amino acid profiles of sap from Tunisian date palm
Makhouf-Gafsi, Ines; Mokni-Ghribi, Abir; Brahim, Bchir et al

in Scientia Agricola (2016), 73(1), 85-90

Date palm sap (Phoenix dactylifera L.), also known as "legmi", is a fresh juice ex¬tracted from date palm trees. The present study aimed to elucidate the effects of collection time (at the beginning of ... [more ▼]

Date palm sap (Phoenix dactylifera L.), also known as "legmi", is a fresh juice ex¬tracted from date palm trees. The present study aimed to elucidate the effects of collection time (at the beginning of the tapping period and after seven days of collection) on the amino acid profile and physico-chemical properties of date palm sap from both male and female trees. Dry matter, protein, amino acid, and sugar profiles were determined using the Kjeldahl method, High-Performance Liquid Chromatography (HPLC), and High-Performance Anion-Exchange Chro¬matography with Pulsed Amperometric Detection (HPAEC-PAD), respectively. Date palm sap from both male and female trees contained high levels of carbohydrates. HPLC analysis showed that this fraction was dominated by sucrose in the sap sample from female trees compared to that from male trees. Male date palm sap was noted to exhibit lower dry matter content than female date palm sap but higher protein, total polyphenol, ash, and amino acid contents. While the major essential amino acids in the sap from male trees consisted of valine and threonine, they were represented by lysine and phenylalanine in sap samples from female trees. Further, Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis showed the presence of a proteinic band of 30 kDa only for the sap from male trees. Taken together, the sap from both male and female date palm trees had a number of properties that are highly valued by the functional food industry. [less ▲]

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See detailPhenolic profile, antibacterial and cytotoxic properties of second grade date extract from Tunisian cultivars (Phoenix dactylifera L.)
Kchaou, Wissal; Abbès, Fatma; Ben Mansour, Riadh et al

in Food Chemistry (2016), (194), 1048-1055

The present study aimed to investigate the phenolic profile of second grade date extracts and evaluate their antimicrobial and cytotoxic activities with regard to some pathogenic microorganisms. Phenolic ... [more ▼]

The present study aimed to investigate the phenolic profile of second grade date extracts and evaluate their antimicrobial and cytotoxic activities with regard to some pathogenic microorganisms. Phenolic content was analyzed by HPLC. Antimicrobial activity was evaluated by the agar disk diffusion method, and in vitro cytotoxic activity was examined by cell proliferation assay. The results revealed that second grade dates presented three benzoic acids, five cinnamic acids and two flavonoids, with the predominance of q-coumaric acid (1998.80 lg/100 g). The antimicrobial activities showed that the date extracts were active against Gram (+) and Gram (-) bacteria, showing marked activity against Escherichia coli with an inhibition zone of 25 mm. Cytotoxicity assays showed that the date extracts were able to inhibit the proliferation of HeLa cell lines. The results confirmed that the date extracts were rich in biologically active compounds that are highly valued in the functional food and nutraceutical industries. [less ▲]

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See detailEffect of γ-radiation on free radicals formation, structural changesand functional properties of wheat starch
Atrous, Hager; Benbettaieb, Nasreddine; Hosni, Faouzi et al

in International Journal of Biological Macromolecules (2015), 80

Wheat starch was treated by different γ-radiation doses (3, 5, 10, 20, 35 and 50 kGy). The effects of γ-radiation on structural, thermal, physicochemical, morphological and rheological properties of wheat ... [more ▼]

Wheat starch was treated by different γ-radiation doses (3, 5, 10, 20, 35 and 50 kGy). The effects of γ-radiation on structural, thermal, physicochemical, morphological and rheological properties of wheat starch were studied. The presence of free radicals after γ-radiation treatment, which number decreased with time was confirmed. Structural analysis revealed decreases in the intensities of the O–H and C–H stretches and glycosidic linkages indicating the depolymerization of amylose and probably amy-lopectin into shorter chain molecules, but showed that γ-radiation treatment did not affect the crystalline structure. Differential scanning calorimetric (DSC) thermograms showed the absence of significant differences in the gelatinization temperatures, as well as the corresponding transition enthalpies since the DSC parameters are related to the crystalline ordering within the granules. Apparent amylose content decreased linearly with increasing irradiation dose leading to an increase in water solubility index. Anincrease in the swelling power was observed after irradiation treatment until 20 kGy, followed by a rapiddecrease at higher doses. Microscopic observations showed that the effect of γ-radiation was more visible on starch pastes than on starch granules. Rheological properties of the starch pastes decreased within creasing irradiation dose as a result of glycosidic bond cleavage. [less ▲]

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See detailEffect of drying methods on physico-chemical and functional properties of chickpea protein concentrates
Ghribi, Abir Mokni; Maklouf Gafsi, Ines; Blecker, Christophe ULg et al

in Journal of Food Engineering (2015), 165

Chickpea protein concentrates (CPCs) were prepared from seed flour by alkaline extraction followed by isoelectric precipitation. The effects of different drying methods (freeze drying and convective ... [more ▼]

Chickpea protein concentrates (CPCs) were prepared from seed flour by alkaline extraction followed by isoelectric precipitation. The effects of different drying methods (freeze drying and convective drying at 40 °C and 50 °C) on physico-chemical and functional properties of CPCs were investigated. CPCs were found to have high contents of protein (61.20–63.12% dry weight basis). Freeze dried concentrate had the highest values of water and oil holding capacities. This drying method gave the lightest CPCs color. The amino acid of CPCs could reach the FAO/WHO requirement (1990) for the essential amino acids for preschool children and the sulfur-containing amino acids were the first limiting amino acids for all three protein concentrates. The solubility-pH profile of different CPCs showed minimum solubility when the pH was between 4.0 and 5.0. All concentrates were able to decrease the interfacial tension. The thermal properties of CPCs were studied by differential scanning calorimetry. CPCs differed significantly (p ≤ 0.05) in peak denaturation temperature and enthalpy of transition. Hence, drying methods used for the preparation of CPCs powders can affect the physico-chemical and functional properties. [less ▲]

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See detailFoamability and Foam Stability of Male and Female Date Palm Sap (Phoenix dactylifera L.) During the Collection Period
Makhlouf-gafsi, Ines; Mokni-ghribi, Abir; Bchir, Brahim et al

in Food Biophysics (2015)

This work aimed to study the influence of date palm sex on the surface properties of date palm sap (DPS) (Phoenix dactylifera L.) during the collection period. The behavior at the interface and foaming ... [more ▼]

This work aimed to study the influence of date palm sex on the surface properties of date palm sap (DPS) (Phoenix dactylifera L.) during the collection period. The behavior at the interface and foaming properties were evaluated via equilibrium surface tension (drop volume) and bubbling method, respectively. Unlike male sap, the female sap was unable to produce foam due to its low rate of adsorption, low average hydrophobicity values, and low bulk viscosity values throughout the collection period. For male sap, there are significant differences (p<0.05) on foaming properties throughout the collection period. In fact, the last 3 weeks of sap collection were characterized by a decrease pace of surface tension which explains the enhancement of both foam capacity and stability. The last week of collection period present the best foam power (0.9). To explain these differences, the interactions of several factors and their affects on foaming properties were examined. Results showed a positive correlation between foam capacity and average hydrophobicity values. In the other hand, foam stability exhibits a positive correlation with the increase of protein concentration and bulk viscosity. [less ▲]

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See detailEffects of enzymatic hydrolysis on conformational and functional properties of chickpea protein isolate
Ghribi, Abir Mokni; Maklouf Gafsi, Ines; Sila, Assaâd et al

in Food Chemistry (2015), 187

The impact of enzymatic hydrolysis by Alcalase on the conformational and functional properties of chickpea protein isolate (CPI) was investigated. The physicochemical, interfacial tension and surface ... [more ▼]

The impact of enzymatic hydrolysis by Alcalase on the conformational and functional properties of chickpea protein isolate (CPI) was investigated. The physicochemical, interfacial tension and surface characteristics of CPI and their hydrolysates (CPH) according to the degree of hydrolysis (DH) were also determined. These parameters were then related to the changes in the emulsification activity (EAI) and stability (ESI). The enzymatic hydrolysis was found to improve protein recovery and solubility, leading to a reduction in the molecular weight bands with a concomitant increase in the intensity and appearance of protein bands having apparent molecular mass below 20 kDa. The interfacial tension decreased from _66.5 mN m_1 for CPI to _59.1 mN m_1 for CPH. A similar trend was observed for the surface charge which declined from _27.55 mV to _16.4 mV for the CPI and CPH, respectively. These changes were found to have a detrimental effect on the EAI and ESI values. [less ▲]

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See detailNutritional and Compositional Study of Desi and Kabuli Chickpea (Cicer Arietinum L.) Flours from Tunisian Cultivars
Ghribi, Abir Mokni; Maklouf, Ines; Blecker, Christophe ULg et al

in Advances in food technology and nutritional sciences (2015), 1(2), 38-47

Two chickpea cultivars (Kabuli, Desi) were analyzed to determine and compare their physical characteristics, chemical composition and functional properties to one another. The main objective is to promote ... [more ▼]

Two chickpea cultivars (Kabuli, Desi) were analyzed to determine and compare their physical characteristics, chemical composition and functional properties to one another. The main objective is to promote their use in food applications and open new opportunities for the development of effective techno-functional additives for use in a wide range of food for¬mulations. Significant differences were revealed among the studied cultivars. Kabuli cultivar has significantly shown (P≤0.05) higher protein content (24.51%), fiber content (21.86%) and lower Water Holding Capacity (WHC) compared to the Desi cultivar. The essential amino ac¬ids were present in chickpea seeds except for tryptophan and cysteine. The sulphur-containing amino acid was the first limiting amino acid. The protein solubility-pH profile of chickpea powders revealed a minimum solubility in the pH between 4 and 5 ranging from 14% to 20% for Kabuli cultivar and 17% to 30% for Desi cultivar. Foaming capacity from different chickpea was observed in the range of 36.9-41% and found significantly different (P≥0.05). Emulsify¬ing Activity (EA) decreased with the increase of flours concentration. Maximum EA (~20%) were observed for Kabuli cultivar. Gelation properties improved when flour concentration in¬creased and the Least Gelation Concentration (LGC) was about 14% for Kabuli cultivar and 16% for Desi cultivar. Chickpea gels were evaluated for their instrumental textural properties. High-quality chickpea flour with improved nutritional properties and good functional proper¬ties could beneficially be used in the formulation of food, such as meat, dairy and bakery prod¬ucts. [less ▲]

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See detailEtude des propriétés moussantes de la sève du palmier dattiers (Phoenix Dactylifera L.)
Makhlouf, Ines; Razafindralambo, Hary; Attia, Hamadi et al

Conference (2015, March 17)

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See detailEffets de l'hydrolyse enzymatique sur propriétés fonctionnelles et conformationnelles des isolats proteiques de pois chiches
Mokni Ghribi, Abir; Maklouf Gafsi, Ines; Sila, Assaad et al

Conference (2015, March 16)

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See detailCaractérisation physico-chimique et structurale de la poudre et des ulvanes de l'algue ulva lactuca
Guidara, Mariem; Yaich, Hela; Garna, Haikel et al

Poster (2015, March 15)

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See detailStructural, functional, and ACE inhibitory properties of water-solublepolysaccharides from chickpea flours
Mokni Ghribi, abir; Sila, Assaâd; Maklouf Gafsi, Ines et al

in International Journal of Biological Macromolecules (2015), 75

tThe present study aimed to characterize and investigate the functional and angiotensin-I convertingenzyme (ACE) inhibition activities of chickpea water-soluble polysaccharides (CPWSP). Physico ... [more ▼]

tThe present study aimed to characterize and investigate the functional and angiotensin-I convertingenzyme (ACE) inhibition activities of chickpea water-soluble polysaccharides (CPWSP). Physico-chemicalcharacteristics were determined by nuclear magnetic resonance spectroscopy (NMR), Fourier transform-infrared spectroscopy (FT-IR) analysis, and X-ray diffractometry (XRD). Functional properties (waterholding capacity: WHC, water solubility index: WSI, swelling capacity: SC, oil holding capacity: OHC,foaming, and emulsion properties) and ACE activities were also investigated using well-established pro-cedures. The FT-IR spectra obtained for the CPWSP revealed two significant peaks, at about 3500 and500 cm−1, which corresponded to the carbohydrate region and were characteristic of polysaccharides.All spectra showed the presence of a broad absorption between 1500 and 670 cm−1, which could beattributed to C−H, C−O, and O−H bands in the polysaccharides. CPWSP had an XRD pattern that wastypical for a semi-crystalline polymer with a major crystalline reflection at 19.6◦C. They also displayedimportant techno-functional properties (SWC, WSI, WHC, and OHC) that can be modulated accordingto temperature. The CPWSP were also noted to display good anti-hypertensive activities. Overall, theresults indicate that CPWSP have attractive chemical, biological, and functional properties that makethem potential promising candidates for application as alternative additives in various food, cosmetic,and pharmaceutical preparations. [less ▲]

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See detailPurification and identification of novel antioxidant peptides from enzymatic hydrolysate of chickpea (Cicer arietinum L.) protein concentrate
Ghribi, Abir Mokni; Sila, Assaâd; Przybylski, Rémi et al

in Journal of functional foods (2015), 12

Enzymatic hydrolysis of chickpea protein concentrate (CP) by Alcalase® and some physiochemical and antioxidant properties of the resulting hydrolysate (CPH) were characterised. CPH displayed higher ... [more ▼]

Enzymatic hydrolysis of chickpea protein concentrate (CP) by Alcalase® and some physiochemical and antioxidant properties of the resulting hydrolysate (CPH) were characterised. CPH displayed higher antioxidant activity than CP. This hydrolysate was fractionated by size exclusion chromatography on a Sephadex G-25 into four major fractions (Fra.I, Fra.II, Fra.III, and Fra.IV). Fraction III, which exhibited the highest DPPH scavenging activity (54% at 1 mg/ml), was then fractionated by reversed-phase high performance liquid chromatography (RP-HPLC). Eleven antioxidant fractions were isolated and two peptide subfractions show antioxidant activity (P3 and P8). The P8 displayed the highest DPPH radicalscavenging activity (67%; at 200 g/ml) among these peptides subfractions. The molecular masses and amino acids sequences of the purified peptides were determined using ESIMS and ESIMS/MS, respectively. Their structures were identified as Asp-His-Gly and Val- Gly-Asp-Ile. These peptides did not show haemolytic activity towards bovine erythrocytes. The results suggest that CPH are good source of natural antioxidants. [less ▲]

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See detailEffect of enzymatic treatment on rheological properties, glass temperature transition and microstructure of date syrup
Abbès, Fatma; Masmoudi, Manel; Kchaou, Wissal et al

in LWT - Food Science and Technology (2015), 60

A knowledge of rheological properties is of importance in processing, handling, process design, product development and quality control. This study investigates the effect of commercial hydrolytic enzymes ... [more ▼]

A knowledge of rheological properties is of importance in processing, handling, process design, product development and quality control. This study investigates the effect of commercial hydrolytic enzymes (pectinase and cellulase) on rheological properties and glass temperature transition of date syrup. Date syrups obtained by enzymatic extraction exhibited a quasi Newtonian behaviour. The enzyme-treated date syrups showed the highest values of activation energy (Ea). Therefore, these syrups showed the most temperature dependency. Dynamic shear results revealed viscous behaviour for date syrups indicating that both syrups displayed liquid-like behaviour. Temperature significantly affected both (G') and (G''). The glass transition temperature (Tg) of date syrups varied between -39.56 and -45.74 °C depending on their composition. Glass transition temperature of date syrups decreased linearly with an increase in water content. [less ▲]

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See detailChemical composition and functional properties of dietary fibre extracted by Englyst and Prosky methods from the alga Ulva lactuca collected in Tunisia
Yaich, Hela; Garna, Haikel; Bchir, Brahim et al

in Algal Research (2015), 9

Nowadays there is a growing trend to find new sources of dietary fibre (DF), such as marine algae by-products that have traditionally been undervalued. In this respect, the aim of the present ... [more ▼]

Nowadays there is a growing trend to find new sources of dietary fibre (DF), such as marine algae by-products that have traditionally been undervalued. In this respect, the aim of the present investigation was firstly to compare two methods of dietary fibre quantification (Englyst and Prosky) and secondly to determine the chemical composition and some of the functional properties of total and insoluble fibres extracted in accordance with the Englyst method. The dietary fibres of dried Ulva lactuca collected from the Tunisian littoral were determined by the Prosky (gravimetric method) and Englyst (enzymatic-chemical method) methods. The two extraction methods (Englyst–Prosky) provided approximately the same values in total fibres (~54%). However, they had different insoluble and soluble fibre contents. U. lactuca contained 20.53% and 31.55% of soluble fibres and 34.37% and 21.54% of insoluble fibres using the Prosky and Englyst methods, respectively. The fractionation of the insoluble dietary fibre concentrate revealed that hemicellulose was the most abundant fraction (32.49%), followed by cellulose (16.59%) and “lignin-like” compounds (1.53%). For both fibre concentrates, the main neutral sugar was glucose (20.70%–27.59%), which corresponded to hemicellulose and cellulose. The water holding capacity of insoluble fibre concentrate was relatively high. It varied between 9.32 g and 10.3 g of water/g of dry fibre at 25 °C and 80 °C, respectively. Nevertheless, the oil holding capacity of the insoluble fibre concentrate was not affected by temperature. It was about 1.08 and 1.01 g of oil/g of dry fibre at 25 °C and 80 °C. Despite the significant functional properties of fibre concentrate, the presence of lead limits its use as an ingredient in the food industry. [less ▲]

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See detailEffet des conditions d'extraction sur la composition et les activités antioxydantes des ulvanes de l'algue Ulva lactucas
Yaich, Hela; Garna, Haikel; Paquot, Michel ULg et al

Conference (2014, April 07)

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See detailEffet du traitement enzymatique sur la composition en polyphénols et sur le pouvoir antioxydant du sirop de dattes
Abbès, Fatma; Wissal, Kchaou; Blecker, Christophe ULg et al

Conference (2014, April 05)

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See detailAdding Value to Agricultural Products and Agrifood Byproducts by Highlighting Functional Ingredients
Besbes, Souhail; Attia, Hamadi; Blecker, Christophe ULg

in Journal of Chemistry (2014), 2014(848231), 1-2

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See detailImproving halva quality with dietary fibres of sesame seed coats and date pulp, enriched with emulsifier
Elleuch, Mohamed; Bedigian, Dorothea; Maazoun, Bouthaina et al

in Food Chemistry (2014), 145

Supplementation of halva with waste products of manufacturing, for example defatted sesame seed coats (testae) and date fibre concentrate, can improve its nutritional and organoleptic qualities. These ... [more ▼]

Supplementation of halva with waste products of manufacturing, for example defatted sesame seed coats (testae) and date fibre concentrate, can improve its nutritional and organoleptic qualities. These constituents provide high fibre content and technological potential for retaining water and fat. Standard halva supplemented with date fibre concentrate, defatted sesame testae and emulsifier was evaluated for oil separation, texture and colour changes, sensory qualities and acceptability to a aste panel. Addition of both fibres with an emulsifier, improved emulsion stability and increased the hardness of halva significantly. The functional properties of sesame testae and date fibres promote nutrition and health, supplying polyphenol antioxidants and laxative benefits. [less ▲]

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