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Mahfoudhi N.,High Institute of Food Industries | Mahfoudhi N.,University of Salerno | Hamdi S.,High Institute of Food Industries
Journal of Polymer Engineering | Year: 2014

The aim of this study was to evaluate the ability of almond gum, as a novel polymer, to encapsulate ß-carotene by spray drying, in comparison with gum arabic. Encapsulation efficiency (EE) was around 66% and 70% using almond gum and gum arabic, respectively, and the reconstituted emulsions had relatively higher particle sizes than the fresh emulsions. A 60-day storage period at 25°C was carried out to investigate the effect of relative humidity (RH) on the kinetic degradation and on the decrease of the color of ß-carotene powders. Results showed that ß-carotene and color degradations were found to fit well with a first-order kinetic model. Degradation rates increased as RH increased, until a value at which the samples become sticky and collapsed (80% RH) when the degradation rate decreased. These results could prove that collapse phenomena were responsible for the decrease of the degradation rate by decreasing the diffusion of oxygen throughout the wall materials.

Rezig L.,High Institute of Food Industries | Chouaibi M.,High Institute of Food Industries | Msaada K.,Center de Biotechnologie de la Technopole de Borj-Cedria | Hamdi S.,High Institute of Food Industries
Industrial Crops and Products | Year: 2012

Seeds of a Tunisian variety (Béjaoui) of pumpkin (Cucurbita maxima) were analysed for their main chemical composition and for their oil properties. Expressed on dry weight basis, seed moisture was 8.46%, whereas contents of proteins, fibre, ash, fat, and total sugars established at 33.92%, 3.97%, 21.97%, 31.57%, and 0.11% respectively. Gas chromatography revealed that the major fatty acids were oleic, linoleic, and palmitic acids (44.11%, 34.77%, and 15.97% respectively). Seed oil was also found to be rich in tocopherols with a predominance of δ-tocopherol (42.27%). The sterol marker β-sisosterol accounted for 39.6% of total sterols contained in seed oil of this variety. Six phenolic acids (protocatechuic, caffeic, syringic, vanillic, p-coumaric and ferulic) were detected, the syringic acid being predominant (7.96. mg/100. g). As a whole, based on its seed oil features, pumpkin may be considered as a valuable source for new multi-purpose products for industrial, cosmetic, and pharmaceutical utilisation. © 2011 Elsevier B.V.

Rezig L.,High Institute of Food Industries | Rezig L.,French National Institute for Agricultural Research | Chibani F.,Center de Biotechnologie de la Technopole de Borj-Cedria | Chouaibi M.,High Institute of Food Industries | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2013

Seed proteins extracted from Tunisian pumpkin seeds (Cucurbita maxima) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients. © 2013 American Chemical Society.

Rezig L.,High Institute of Food Industries | Rezig L.,French National Institute for Agricultural Research | Riaublanc A.,French National Institute for Agricultural Research | Chouaibi M.,High Institute of Food Industries | And 2 more authors.
International Journal of Food Properties | Year: 2016

Protein fractions were extracted from pumpkin (Cucurbita maxima) seeds with deionized water, salt solution, and alkali solution, and characterized under alkaline (pH 8) and ionic strength conditions for protein solubility, interfacial pressure, and functional properties. The supernatants obtained from the protein fractions after hydration and centrifugation were designed deionized water supernatant, salt solution supernatant, and alkali solution supernatant. All protein fractions showed poor foamability and very low stability. The designed deionized water supernatant presented the highest emulsifying properties. In terms of stability, designed deionized water supernatant emulsions flocculate during storage but with low rates of coalescence compared to the two other fractions. © 2015 Taylor and Francis Group, LLC.

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