Heating effects on some quality caracteristics of date seed oil.

peer reviewe

Osmotic dehydration of pomegranate seeds (PUNICA GRANATUM L.)

Osmotic dehydration of pomegranate seeds was carried out at different temperatures (30, 40, 50°C) in a 55°Brix solution of sucrose, glucose, and mixture sucrose & glucose (50:50 wt/wt). The most significant changes of water loss and solids gain took place during the first 20 min of dewatering. During this period, seeds water loss was estimated to 46% in sucrose, 37% in glucose and 41% in mix glucose/sucrose solution. The increase of temperature favoured the increase of water loss, weight reduction, solids gain and effective diffusivity. Differential scanning calorimetry data provided complementary information on the mobility changes of water and solute in osmodehydrated pomegranate seeds. The ratio between % frozen water and % unfreezable water decreased from 5 to 0.5 during the process. That involving the presence of very tightly bound water to the sample, which is very difficult to eliminate with this process. It also appeared that glass transition temperature depends on the types of sugar

Characteristic Profiles of an Original Drink Sap from Male and Female Deglet Nour Palm ( Phoenix dactylifera

This work aimed to evaluate the nutritional quality of a typical natural drink from male and female Deglet Nour (DN) date palm (Phoenix dactylifera L.) during the collection period. Dry matter, protein, amino acids, and sugar profiles were determined using AFNOR norm, Kjeldahl method, HPLC, and HPAEC-PAD, respectively. The male sap dry matter content was higher than that of the female. It decreased significantly through the tapping period. During the harvest, the male sap protein content decreased but increased significantly in the female sap. Finally, sugar fraction, for both male and female DN sap, was dominated by sucrose, glucose, fructose, and a small amount of myo-inositol. During the collection time, sugar content is affected by the sex especially for myo-inositol content that increased significantly in the female date sap, unlike that of the male one. This may be related to the fact that the male palm is more resistant to physiological stress, inducing myo-inositol formation during tapping

Nutritional and Compositional Study of Desi and Kabuli Chickpea (Cicer Arietinum L.) Flours from Tunisian Cultivars

peer reviewedTwo 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

Preparation and characterization of jellies with reduced sugar content from date (Phoenix dactylifera L.) and lemon (Citrus limon L.) by-products

Introduction. The increase in diabetes and obesity has increased the demand for reduced sugar products such as jams and jellies. Four jelly formulations were prepared using date juice which was enriched with pectin and lemon flavors. Materials and methods. Reduced quantities of sugars (45% and 55%) were added to the juice at different pH (3 and 3.5). The prepared jellies were evaluated for physico-chemical and sensory properties. Results and discussion. The water activity values for jellies ranged between 0.767 and 0.804, making them safe from the development of the majority of bacteria. The addition of less quantity of sugar, as well as the decreased pH, resulted in significantly firmer jellies, with higher adhesiveness, chewiness and cohesiveness. Sensory evaluation showed that the prepared jellies averaged 4.17-5.47 and 4.59-5.67 for taste and firmness, respectively, in a 7-point hedonic scale consumer acceptance study. The most appreciated jellies were those prepared with the lowest sugar content, with a slight preference for that with a pH of 3.5. Significant differences were not found between scores for the other sensory attributes (color, transparency, brightness, odor and springiness)