References of "Blecker, Christophe"
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See detailHPLC profile and dynamic surface properties of the proteose-peptone fraction from bovine milk and from whey protein concentrate
Innocente, Nadia; Biasutti, Marialuisa; Blecker, Christophe ULg

in International Dairy Journal (2011), 21(4), 222-228

Extraction of proteose-peptones (PPs) was carried out from fresh milk, from milk after prolonged incubation (12 days at 37 degrees C) and from two different whey protein concentrates (WPCs). The high ... [more ▼]

Extraction of proteose-peptones (PPs) was carried out from fresh milk, from milk after prolonged incubation (12 days at 37 degrees C) and from two different whey protein concentrates (WPCs). The high performance liquid chromatography profiles of these extracts were compared. PPs eluted as three chromatographic peaks, which increased during milk incubation. The PP extracts from WPCs showed a number of peaks that are attributable to small peptides belonging to the proteose-peptone fraction and probably derive from proteolysis during storage of WPC. The dynamic properties at the air-water interface of the PP extracts were investigated by the drop-volume method. The PPs extracted from fresh milk showed the lowest values and a more rapid reduction in surface tension. PPs from WPCs were found to be effective as surfactants, even though a less marked reduction in surface tension compared with PPs from milk samples was shown. (C) 2011 Elsevier Ltd. All rights reserved. [less ▲]

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See detailPRODUCTION OF XANTHAN GUM FROM XANTHOMONAS CAMPESTRIS NRRL B-1459 BY FERMENTATION OF DATE JUICE PALM BY-PRODUCTS (PHOENIX DACTYLIFERA L.)
Ben Salah, Riadh; Chaari, Kacem; Besbes, Souhail et al

in Journal of Food Process Engineering (2011), 34(2), 457-474

In this work, we studied the possibility to use date juice for xanthan gum production by Xanthomonas campestris NRRL B-1459. The results showed that this strain has a high ability to metabolize date juice ... [more ▼]

In this work, we studied the possibility to use date juice for xanthan gum production by Xanthomonas campestris NRRL B-1459. The results showed that this strain has a high ability to metabolize date juice. The data on optimization of physiological conditions of fermentation, pH, temperature, inoculum's size, glucose and nitrogen concentration showed that the maximum xanthan yield of 24.5 g/L was obtained from 60 g/L glucose, 3 g/L ammonium sulphate when batch fermentation was carried with 5% inoculum's size at pH 7, 28C, 48 h, on a rotary orbital shaker at 180 rpm. The polysaccharide purified by high performance liquid chromatography and analyzed by thin layer chromatography contained glucose, glucoronic acid and mannose. PRACTICAL APPLICATIONS Agri-food by-products rich in sugars may be used to produce high added value food ingredients such as xanthan gum. No work has studied the production of this polysaccharide from date. This study is focused on given value addition to date by-product (hard texture) by production of xanthan gum. The effect of several parameters (pH, temperature, inoculum's size, agitation speed, nitrogen source and carbon concentration) on production yield was investigated. [less ▲]

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See detailDate syrup: Effect of hydrolytic enzymes (pectinase/cellulase) on physico-chemical characteristics, sensory and functional properties
Abbes, Fatma; Bouaziz, Mohamed Ali; Blecker, Christophe ULg et al

in Lwt-Food Science And Technology (2011), 44(8), 1827-1834

This work is a contribution to give value addition to second grade dates (with hard texture) by the production of enzymatically treated syrup with high commercial value. It was observed that the pulp ... [more ▼]

This work is a contribution to give value addition to second grade dates (with hard texture) by the production of enzymatically treated syrup with high commercial value. It was observed that the pulp:water at ratio 1:3 treated with 50 U of pectinase and 5 U of cellulase during 120 min at 50 degrees C gave the highest recovery of total soluble solids (72.37 g of total soluble solids/100 g fresh basis) and the lower turbidity (186.45 NTU) compared with control without enzyme addition (Total soluble solids yields: 66.34 g of total soluble solids/100 g fresh basis and turbidity: 1513 NTU). physico-chemical measurements indicated that carbohydrates were predominant in all date varieties as well as their syrups (similar to 69.59-83.76 g/100 g dry matter in dates and similar to 62.14-74.68 g/100 g fresh weight in syrup). Allig variety was characterised by a high content of reducing sugars content (similar to 77.91 g/100 g dry matter), contrary to Deglet Nour (similar to 23.17 g/100 g dry matter) and Kentichi (similar to 21.3 g/100 g dry matter). The CIE L* a* b* colour values of the enzyme-treated date syrup of Deglet Nour, Allig and Kentichi variety showed lighter colours (L* values ranging from 24.16 to 44) than the control without enzyme (L* values ranging from 0.545 to 17.2). Hedonic evaluation showed that enzyme-treated date syrup was more appreciated by consumers. Microbiological study showed that date syrups were free from aerobes, moulds, coliforms and enterobacteriaceae and were microbiologically stable during five months storage. Results suggested that enzymatic treatment could be used for production of date syrup with high commercial value (C) 2011 Elsevier Ltd. All rights reserved. [less ▲]

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See detailInfluence of oven-drying temperature on physico-chemical and functional properties of date fibre concentrates
Borchani, C.; Besbes, S.; Masmoudi, M. et al

in Food and Bioprocess Technology (2011)

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence ... [more ▼]

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence of oven-drying temperatures of date fibre concentrates (DFC) on their physicochemical and functional properties for possible use as a potential fibre source in the enrichment of food. DFC from 11 Tunisian date cultivars were dried at different temperatures (40, 50 and 60 °C) and analysed regarding proximate composition (moisture, ash, protein and lipids), physicochemical (water activity (aw), pH) and functional properties (water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and emulsifying capacity (EC)). DFC dried at different temperatures showed interesting functional characteristics such as hydration properties, high OHC (2.73–4.60 g oil/g dry fibre) and EC (5.93–12.87%) values. Although drying temperatures promoted little modifications affecting the physicochemical properties of DFC, significant decreases in WHC, SC and EC of DFC were noticed at the highest temperature (60 °C) for most of the date varieties. The observed influence of drying temperature on functional DFC properties calls for the use of low temperature in order to obtain DFC as suitable food ingredient. [less ▲]

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See detailImpact of formic/acetic acid and ammonia pre-treatments on chemical structure and physico-chemical properties of Miscanthus x giganteus lignins
Vanderghem, Caroline ULg; Richel, Aurore ULg; Jacquet, Nicolas ULg et al

in Polymer Degradation & Stability (2011), 96(10), 1761-1770

Miscanthus x giganteus was treated with formic acid/acetic acid/water (30/50/20 v/v) for 3 h at 107 C and 80° C, and soaking in aqueous ammonia (25% w/w) for 6 h at 60 C. The effects of these ... [more ▼]

Miscanthus x giganteus was treated with formic acid/acetic acid/water (30/50/20 v/v) for 3 h at 107 C and 80° C, and soaking in aqueous ammonia (25% w/w) for 6 h at 60 C. The effects of these fractionation processes on chemical structure, physico-chemical properties and antioxidant activity of extracted lignins were investigated. Lignins were characterized by their purity, carbohydrate composition, thermal stability, molecular weight and by Fourier transform infrared (FTIR), 1H and quantitative 13C nuclear magnetic resonance (NMR), adiabatic broadband {13C-1H} 2D heteronuclear (multiplicity edited) single quantum coherence (g-HSQCAD). The radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) was also investigated. Formic/acetic acid pretreatment performed in milder conditions (80° C for 3 h) gave a delignification percentage of 44.7% and soaking in aqueous ammonia 36.3%. Formic/acetic acid pretreatment performed in harsh conditions (107°C for 3 h) was more effective for extensive delignification (86.5%) and delivered the most pure lignin (80%). The three lignin fractions contained carbohydrate in different extent: 3% for the lignin obtained after the formic/acetic acid pretreatment performed at 107 C (FAL-107), 5.8% for the formic/acetic acid performed at 80°C (FAL-80) and 13.7% for the ammonia lignin (AL). The acid pretreatment in harsh conditions (FAL-107) resulted in cleavage of b-O-4' bonds and aromatic C-C. Repolymerisation was thought to originate from formation of new aromatic C-O linkages. Under milder conditions (FAL-80) less b-O-4' linkages were broken and repolymerisation took place to a lesser extent. Ammonia lignin was not degraded to a significant extent and resulted in the highest weight average 3140 g mol -1. Despite the fact of FAL-107 repolymerisation, significant phenolic hydroxyls remained free, explaining the greater antioxidant activity. [less ▲]

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See detailWill isomalto-oligosaccharides, a well-established functional food in Asia, break through the European and American market? The status of knowledge on these prebiotics
Goffin, Dorothée ULg; Delzenne, Nathalie; Blecker, Christophe ULg et al

in Critical Reviews in Food Science & Nutrition (2011)

This critical review article present the current state of knowledge on isomaltooligosaccharides, some well known functional oligosaccharides in Asia, to evaluate their potential as emergent prebiotics in ... [more ▼]

This critical review article present the current state of knowledge on isomaltooligosaccharides, some well known functional oligosaccharides in Asia, to evaluate their potential as emergent prebiotics in the American and European functional food market. It includes first a unique inventory of the different families of compounds which have been considered as IMO and their specific structure. A description of the different production methods including the involved enzymes and their specific activities, the substrates and the types of IMO produced. Considering the structural complexity of IMO products, specific characterization methods are described as well as purification methods which enable the riddance of digestible oligosaccharides. Finally an extensive review of their techno-functional and nutritional properties enables to place IMO inside the growing prebiotic market. This review is of a particular interest considering that IMO commercialization in America and Europe is a topical subject due to the recent submission, by Bioneutra INC. (Canada), of a novel food file to the UK Food Standards Agency as well as several patents for IMO production. [less ▲]

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See detailEffect of drying methods on physico-chemical and antioxidant properties of date fibre concentrates
Borchani, I.; Besbes, S.; Masmoudi, M. et al

in Food Chemistry (2011), 125

Effects of different drying methods (freeze-, oven- and sun-drying) on physico-chemical properties of date fibre concentrates (DFC) from three potential Tunisian cultivars were investigated. DFC had high ... [more ▼]

Effects of different drying methods (freeze-, oven- and sun-drying) on physico-chemical properties of date fibre concentrates (DFC) from three potential Tunisian cultivars were investigated. DFC had high contents of dietary fibre (71.01–93.46% dry matter), with high proportions of insoluble dietary fibre. Freeze dried DFC had the highest values of swelling, water holding and oil holding capacities. This drying method gave also the lightest DFC colour. Kentichi fibre produced by freeze-drying had the highest viscosity and the lowest bulkier particles. The present work assessed polyphenol content and antioxidant activity of DFC using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The highest polyphenol content was found for freeze dried DFC, contrary to radical scavenging activity which was not affected by drying methods. Results suggest that freeze dried DFC had the highest potential to be used as a functional ingredient in food products. [less ▲]

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See detailDietary fibre and fibre-rich by-products of food processing characterisation, technological functionality and commercial applications: a review
Elleuch, mohamed; Bedigian, Dorothy; Roiseux, Olivier et al

in Food Chemistry (2011), 124

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See detailSynthèse des connaissances sur la déshydratation osmotique
Bchir, Brahim; Besbes, Souhail; Giet, Jean-Michel et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(1), 129-142

Parmi les procédés de conservation des produits végétaux, la déshydratation osmotique présente un intérêt économique et nutritionnel certain. Cette technique, économe en énergie, est susceptible de ... [more ▼]

Parmi les procédés de conservation des produits végétaux, la déshydratation osmotique présente un intérêt économique et nutritionnel certain. Cette technique, économe en énergie, est susceptible de prolonger la période de disponibilité des produits alimentaires et leur confère des propriétés sensorielles nouvelles et appréciées. Elle permet ainsi aux acteurs de la filière agro-alimentaire d’écouler leurs productions à de meilleurs prix et aux consommateurs d’en disposer tout au long de l’année. Cette technique est un outil facile à mettre en place, surtout dans les pays en voie de développement, en raison de son faible cout. Le présent article a pour objectif de présenter une synthèse de la littérature concernant la technique de déshydratation osmotique afin d’en rappeler les bases théoriques et pratiques, mais aussi d’en préciser les nouvelles tendances et voies de recherches récentes. [less ▲]

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See detailFlaxseed proteins: food uses and health benefits flaxseed proteins
Rabetafika, Holy-Nadia ULg; Van Remoortel, Vinciane ULg; Danthine, Sabine ULg et al

in International Journal of Food Science & Technology (2011), 46(2), 221-228

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See detailEffect of ageing on different egg yolk fractions on surface properties at the air–water interface
Freschi, Jérôme ULg; Razafindralambo, Hary ULg; Danthine, Sabine ULg et al

in International Journal of Food Science & Technology (2011), 46

The aim of this study was to evaluate the impact of egg ageing on the surface properties of whole and fractionated yolk at the air–water interface. Eggs were stored at 4 Cfor 24 h, 1 week and 3 weeks ... [more ▼]

The aim of this study was to evaluate the impact of egg ageing on the surface properties of whole and fractionated yolk at the air–water interface. Eggs were stored at 4 Cfor 24 h, 1 week and 3 weeks after laying.A laboratory scale fractionation process was then applied at each ageing time. Egg yolk was separated into two fractions, plasma composed of low-density lipoproteins (LDLs) and livetins, and granules formed by highdensity lipoproteins (HDLs), phosvitins and LDLg (g = granule). Moreover, recombined plasma and granules fractions were investigated to highlight a potential synergic effect on surface properties. Results have shown the main contribution of LDLs on surface properties of yolk and an improvement of granules surface properties when they are disrupted. Moreover, ageing affected surface properties differently depending on the considered fractions. Broken LDLsand disrupted granules could explain this observed behaviour. Recombined fractions showed different compression isotherms at the air–water interface than whole yolk. [less ▲]

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See detailRegio-selective enzymatic interesterification combined with dry fractionation to produce cocoa butter equivalent.
Danthine, Sabine ULg; Vanden Bossche, sandrine ULg; Maes, Jeroen et al

in Récents Progrès en Génie des Procédés (2011), 101

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See detailSynthesis and Surface-Active Properties of Uronic Amide Derivatives, Surfactants from Renewable Organic Raw Materials
Laurent, Pascal ULg; Razafindralambo, Hary ULg; Wathelet, Bernard ULg et al

in Journal of Surfactants and Detergents (2011), 14(1), 51-63

Short chemical syntheses were developed to produce a new set of surfactants from uronic acids derived from widely available raw material. Three different strategies were used to synthesise uronic amide ... [more ▼]

Short chemical syntheses were developed to produce a new set of surfactants from uronic acids derived from widely available raw material. Three different strategies were used to synthesise uronic amide derivatives, the structures of which were totally characterized by spectrometric methods (IR, MS, 1H-RMN and 13C-RMN). The best one, using an acid chloride as synthetic intermediate, furnished the expected amides as a mixture of anomers in 46 to 58 % global yield. Surface-active properties (CMC, g cmc, Tmax, Amin) of homologous series of uronic acid N-alkylamides from C8 to C18 were also assessed. In general, these sugar-based surfactants exhibited good surface-activities, and appeared as valuable non ionic surfactants compared to Triton X-100, the most well-known non ionic surfactant. Increasing the alkyl chain length influenced the CMC values for both glucuronic and galacturonic N-alkylamide derivatives. The galacturonic N-alkylamides decreased g cmc at slower values than their counterpart's glucuronic N-alkylamides. [less ▲]

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See detailMid infrared and fluorescence spectroscopies coupled with factorial discriminant analysis technique to identify sheep milk from different feeding systems
Karoui, Romdhane; Hammami, Moncef; Rouissi, Hamadi et al

in Food Chemistry (2011), 127(2), 743-748

Mid infrared spectroscopy (MIR) combined with multivariate data analysis was used to discriminate between ewes milk samples according to their feeding systems (controls, ewes fed scotch bean and ewes fed ... [more ▼]

Mid infrared spectroscopy (MIR) combined with multivariate data analysis was used to discriminate between ewes milk samples according to their feeding systems (controls, ewes fed scotch bean and ewes fed soybean). The MIR spectra were scanned throughout the first 11 weeks of the lactation stage. When factorial discriminant analysis (FDA) with leave one-out cross-validation was applied, separately, to the three spectral regions in the MIR (i.e. 3000-2800, 1700-1500 and 1500-900 cm(-1)), the classification rate was not satisfactory. Therefore, the first principal component (PCs) scores (corresponding to 3, 10 and 10 for, respectively, the 3000-2800, 1700-1500 and 1500-900 cm(-1)) of the principal component analysis (PCA) extracted from each of the data sets were pooled (concatenated) into a single matrix and analysed by FDA. Correct classification amounting to 71.7% was obtained. Finally, the same procedure was applied to the MIR and fluorescence data sets and 98% of milk samples were found to be correctly classified. Milk samples belonging to control and soybean groups were 100% correctly classified. Regarding milk samples originating from the scotch bean group, only 2 out of 33 samples were misclassified. It was concluded that concatenation of the data sets collected from the two spectroscopic techniques is an efficient tool for authenticating milk samples according to their feeding systems, regardless of the lactation stage. (C) 2011 Published by Elsevier Ltd. [less ▲]

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See detailEffect of Air-Drying Conditions on Physico-chemical Properties of Osmotically Pre-treated Pomegranate Seeds
Bchir, Brahim ULg; Besbes, Souhail; Karoui, Romdhane et al

in Food and Bioprocess Technology (2010)

The drying of pomegranate seeds was investigated <br />at 40 °C, 50 °C and 60 °C with air velocity of 2 m/s. <br />Prior to drying, seeds were osmodehydrated in 55 °Brix <br />sucrose solution for 20 min ... [more ▼]

The drying of pomegranate seeds was investigated <br />at 40 °C, 50 °C and 60 °C with air velocity of 2 m/s. <br />Prior to drying, seeds were osmodehydrated in 55 °Brix <br />sucrose solution for 20 min at 50 °C. The drying kinetics <br />and the effects of osmotic dehydration (OD) and air-drying <br />temperature on antioxidant capacity, total phenolics, colour <br />and texture were determined. Analysis of variance revealed <br />that OD and air-drying temperature have a significant <br />influence on the quality of seeds. Both anthocyanin and <br />total phenolic contents decreased when air-drying temperature <br />increased. The radical diphenylpicril-hydrazyl activity <br />showed the lowest antioxidant activity at 60 °C. Both <br />chromatic parameters (L*, C* and h°) and browning index <br />were affected by drying temperatures, which contributed to <br />the discolouring of seeds. The final product has 22%, 20% <br />and 16% of moisture; 0.630, 0.478 and 0.414 of aw; 151, <br />141 and 134 mg gallic acid equivalent/100 g fresh matter <br />(FM) of total phenolics; 40, 24, 20 mg/100 g FM of <br />anthocyanins and 46%, 39% and 31% of antioxidant <br />activity, for drying temperatures of 40 °C, 50 °C and <br />60 °C, respectively. In view of these results, the temperature <br />of 40 °C is recommended as it has the lowest impact on <br />the quality parameters of the seeds. Differential scanning <br />calorimetry data provided complementary information on <br />the mobility changes of water during drying. Glass <br />transition temperature (Tg′) depends on moisture content <br />and as consequence, on drying conditions. In fact, Tg′ of <br />seeds dried at 60 °C (Tg′=−21 °C) was higher than those <br />dried at 50 °C (Tg′=−28 °C) or 40 °C (Tg′=−31 °C) and <br />osmodehydrated seeds (Tg′=−34 °C). During OD and <br />drying process, the texture of seeds changed. The thickness <br />of seeds shrank by 55% at 60 °C. [less ▲]

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