Heating Effects On Some Quality Characteristics Of Date Seed Oil

Effects of heating on some quality characteristics of date seed oil from two cultivars (Deglet Nour and Allig) has been investigated using an accelerated test in a Rancimat system. Fatty acid, viscosity, absorptivity at 232 and 270 nm, colour and total melting enthalpy of Deglet Nour seed oil were less changed compared to that of Allig seed oil, because the former contained a higher amount of total phenolic compounds (526 lg/g against 215 lg/g) and a lower content of unsaturated fatty acids. Viscosity and absorptivity at 232 nm and at 270 nm increased rapidly after reaching the oxidation induction time. Differential scanning calorimetry melting profiles of date seed oils were also changed after heating in the Rancimat. Melting enthalpies seemed to be constant during the initial stages of Rancimat treatment and then reduced after the induction time was reached. The obtained data shows that date seed oils were resistant to thermal treatment during a long period ( 30–40 h). This may indicate that they could bear thermal treatments that could be applied in refining procedures or in culinary treatments such as frying and cooking conditions. We could also expect that they may have a good shelf life

Date seed oil: Phenolic, tocopherol and sterol profiles

Oils extracted from the seeds of two date palm (Phoenix dactylifera L) cultivars, Deglet Nour and Allig, collected from Tunisia, were compared in terms of phenolic, tocopherol and,sterol profiles. These minor components are not only very important for functional properties of oils (oxidation resistance, taste, aroma and color), but could also have many health benefits. Total phenols, considered as the principal source of oil oxidation resistance, ranged from 520.81 for Deglet Nour to 220.32 mg/kg for Allig. High performance liquid chromatography revealed eight identified peaks for which the major component was hydroxytyrosol (10.21%) for Deglet Nour and tyrosol for Allig (8.10%). Total sterol content was 3500 and 3000 mg/kg for Deglet Nour and Allig, respectively. The sterol marker, beta-sitosterol, accounted for 83.31 and 78.66% of total sterols in Deglet Nour and Allig seed oils, respectively. Alpha-tocopherol was the predominant component in both date seed oils (24.97-38.85%)

The addition effect of Tunisian date seed fibers on the quality of chocolate spreads

peer reviewedNovel chocolate spreads were enriched by soluble and insoluble dietary fibers from Tunisian Deglet Nour date seeds at 1, 2, 3, 4 and 5% levels in the conventional chocolate spread. Defatted Deglet Nour date seeds (DNDS), date seed soluble fiber concentrate (DSSFC) and date seed insoluble fiber concentrate (DSIFC) were characterized by high levels of dietary fibers (80 – 90%). Chocolate spread enriched with 5% of DSSFC presented the highest OBC (304.62%) compared to the control (102%). Whatever the DSIFC and DSSFC incorporation levels, no significant difference was recorded between the firmness, chewiness and adhesiveness of prepared chocolate spreads compared to the control (P<0.05). Sensory evaluation revealed that all prepared chocolate spreads enriched by DSIFC and DSSFC were accepted by panelists. These results indicated the value of date seeds as new source of dietary fibers to develop chocolate spread and could also improve health benefits and functional properties

Protein And Amino Acid Profiles Of Tunisian Deglet Nour And Allig Date Palm Fruit Seeds

Introduction. The fruit of the date palm (Phoenix dactylifera L.) is an important crop of the arid and semi-arid areas of the world. It has always played a genuine economic and social part in the lives of the people of these areas. Nevertheless, there are few studies related to the composition and the functional properties of the different components (fibres, fats and proteins) of the date seeds. In order to obtain more information on the nutritive value and the chemical composition of the pits of the most important and most valuable Tunisian date palm varieties (Deglet Nour and Allig), we studied their profiles of proteins and amino acids. Materials and methods. Date seeds of two Tunisian cultivars, Deglet Nour and Allig, were separately milled in a heavy-duty grinder to pass 1–2 mm screens; then, they were preserved at – 20 °C until analysis. The soluble proteins from defatted date seeds were extracted with water at pH 10, and were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Results and discussion. Amino acid profiles revealed that date seeds from the Deglet Nour and Allig varieties contained the majority of essential amino acids: lysine, isoleucine, leucine, methionine, threonine, valine and phenylalanine. Seventeen amino acids were detected in the seeds of the two studied cultivars. Glutamic acid was the major amino acid in Deglet Nour and Allig date seeds, representing 17.83% and 16.77%, respectively, of the total amino acids. Date seeds appeared to contain a number of proteins with molecular weights ranging from 22 kDa to 70 kDa. Three prominent bands appeared at 32 kDa, 60 kDa and 70 kDa