[en] Physicochemical properties of sap from Deglet Nour date palm (Phoenix dactylifera L.) were studied. Composition analysis revealed (on a dry-weight basis) a high content of carbohydrates (94.98 g/100 g of dry matter basis) mainly sucrose, 2.72 g/100g (dry matter basis) of proteins and 2.29 g/100 g (dry matter basis) of ash. Date palm sap also contains 7.64 mg gallic acid equivalent/100 ml of total polyphenol. Thus, date palm sap showed antioxidant activity with a percentage inhibition of the DPPH radical value of 47.64%. Surface and foaming properties were also performed by drop volume and bubbling method, respectively. Equilibrium surface tension of fresh sap was 63.51 mN/m. Freeze-drying method preserved surface activity. Native sap showed better foam power (1.03) and foam stability (1150 s) than solutions prepared from lyophilised sap (5-30 g /100g of solution). Results demonstrated that this natural juice could be regarded as functional food due to its high nutritional value, antioxidant activity, surface activity, and foam power.
Food and Agriculture Organization of the United Nations.. Agro-statistics Database FAOSTAT:. Rome, 2006.
Mzali, M.T.; Lasram, M.; Rhouma, A. Le palmier dattier (Phoenix dactylifera L.). In L'arboriculture fruitière en Tunisie; Ed: ORBIS impression: Tunis, 2002; 201-229.
Barreveld, W.H. Date palms products.FAO: Rome, Italy, 1993; 101.
Al- Farsi, M.A. Clarification of date juice. International Journal of Food Science and Technology 2003, 38, 241-245.
Besbes, S.; Blecker, C.; Deroanne, C.; Lognay, G.; Drida, N.E.; Attia, H. Heating effects on some quality characteristics of date seed oil. Food Chemistry 2005, 91, 469-476.
Apriyantono, A.; Aristyani, A.; Nurhayati Lidya, Y.; Budiyanto, S.; Soekarto, S.T. Rate of browning reaction during preparation of coconut and palm sugar. International Congress Series 2002, 1245, 275-278.
Ho, C.W.; Wan Aida, W.M.; Maskat, M.Y.; Osman, H. Changes in volatile compounds of palm sap (Arenga pinnata) during the heating process for production of palm sugar. Food Chemistry 2007, 102, 1156-1162.
Atputharajah, J.D.; Widanapathirana, S.; Samarajeewa, U. Microbiology and biochemistry of natural fermentation of coconut palm sap. Food Microbiology 1986, 3, 273-280.
Shamala, T.R.; Sreekantiah, K.R. Microbiological and biochemical studies on traditional Indian palm wine fermentation. Food Microbiology 1988, 5, 157-162.
Naidu, S.J.; Misra, M.K. Production and consumption of wild date palm sap and country liquor in two tribal village ecosystems of eastern ghats of Orissa, India. Bioresource Technology 1998, 63, 267-273.
Umerie, S.C. Caramel production from saps of African oil palm (Elaeis guineensis) and wine palm (Raphia hookeri) trees. Bioresource Technology 2000, 75, 167-169.
AFNOR. Lait et produits laitiers. Détermination de la matière sèche NF V 04-207; 1999; 137-138.
AOAC. Association of the Official Analytical Chemists. In Official methods of analysis of the Association of the Official Analytical Chemists; Firestone, D., Ed.; Association of the Official Analytical Chemists Inc, Arlington, 1990; p 1298.
Barminas, J.T.; James, M.K.; Abubakar, U.M. Chemical composition of seeds and oil of Xylopia aethiopica grown in Nigeria. Plant Foods for Human Nutrition 1999, 53, 193-198.
Gutfinger, T. Polyphenols in olive virgin oils. Journal of the American oils chemists Society 1981, 58, 966-968.
Turkmen, N.; Sari, F.; Poyrazoglu, E.S.; Velioglu, Y.S. Effects of prolonged heating on antioxidant activity and colour of honey. Food Chemistry 2006, 95, 653-657.
Razafindralambo, H.L.H. Contribution à ĺtude des propriétés tensioactives des lipopeptides de Bacillus subtilis. Ph.D Thesis Faculté Universitaire des Sciences Agronomiques de Gembloux, Belgique,1996; 200 pp.
Fains, A.; Bertrand, D.; Baniel, A.; Popineau, Y. Stability and texture of protein foams: a study by video image analysis. Food hydrocolloids 1997, 11, 63-69. (Pubitemid 127802392)
Ritthipairote, T.; Youravong, W.; Wanichapichart, P. Flux, rejection and fouling during microfiltration and ultrafiltration of sugar palm sap using a pilot plant scale. Songklanakarin Journal of Science and Technology 2006, 28, 817-828.
Dalibard, C. Overall view on the tradition of tapping palm trees and prospects for animal production, Livestock research for rural development. International Relations Service, Ministry of Agriculture Paris, 1999; 11 (1), 1-42.
Akochi, K.E.; Alli, I.; Kermasha, S. Characterisation of the pyrazines formed during the processing of maple syrup. Journal of Agriculture and Food Chemistry 1997, 45, 3368-3373.
Cheikh-Rouhou, S.; Ben Amara, W.; Besbes, S.; Blecker, C.; Attia, H. Essai de valorisation d́carts de triage de dattes: Elaboration et caractérisation d'un extrait concentré de la pulpe. Microbiologie Hygiène Alimentaire 2006, 18, 3-12.
Besbes, S.; Blecker, C.; Deroanne, C.; Drira, N. E.; Attia, H. Date seeds: chemical composition and characteristic profiles of the lipid fraction. Food Chemistry 2004, 84, 577-584.
Bolade, M. K.; Bello, S.B. Selected physicochemical properties of flour from the root of African fan palm (Borassus aethiopum). International Journal of Food Properties 2006, 9, 701-713.
Regnault, R.C.; Hadidane, R.; Biard, J.F.; Boukef, K. High performance liquid and thin-layer chromatographic determination of phenolic acids in palm (Phoenix dactylifera) products. Food Chemistry 1978, 25, 61-71.
Mansouri, A.; Embarek, G.; Kokkalou, E.; Kefalas, P. Phenolic profile and antioxidant activity of the Algerian ripe date palm fruit (Phoenix dactylifera). Food Chemistry 2005, 89, 411-420.
Quintas, M.; Brandão, T.R.S.; Silva, C.L.M.; Cunha, RL. Rheology of supersaturated sucrose solutions. Journal of Food Engineering 2006, 77, 844-852.
Van Vliet, T.; Martina, A.H.; Bos, M.A. Gelation and interfacial behaviour of vegetable proteins. Current Opinion in Colloid and Interface Science 2002, 7, 462-468.
Damodaran, S. Protein stabilisation of emulsions and foams. Journal of Food Science 2005, 70, 54-66.
Martin, A.H.; Grolle, K.; Bos, M.A.; Stuart, M.A.C.; Van Vliet, T. Network forming properties of various proteins adsorbed at the air-water interface in relation to foam stability. Journal of Colloid and Interface Science 2002, 254, 175-183.
Bos, M.A.; Dunnewind, B. Foams and surface rheological properties of â-casein, gliadin and glycinin. Colloid and Surfaces B: Biointerfaces 2003. 31, 95-105.
Allison, S.D.; Chang, B.; Randolph, T.W.; Carpenter, J.F. Hydrogen Bonding between Sugar and Protein Is Responsible for Inhibition of Dehydration-Induced Protein Unfolding. Archives of Biochemistry and Biophysics 1999, 365, 289-298.
Wang, W. Lyophilization and development of solid protein pharmaceuticals. International Journal of Pharmaceutics 2000, 203, 1-60.
Makri, E.A.; Doxastakis, G.I. Surface tension of Phaselous vulgaris and coccineus proteins and effect of polysaccharides on their foaming properties. Food Chemistry 2007, 101, 37-48.
Aroulmoji, V.; Aguié-Béghin, V.; Mathlouthi, M.; Douillard, R. Effect of sucrose on the properties of caffeine adsorption layers at the air/solution interface. Journal of Colloid and Interface Science 2004, 276, 269-276.
Permprasert, J.; Devahastin, S. Evaluation of the effects of some additives and pH on surface tension of aqueous solutions using a drop-weight method. Journal of Food Engineering 2005, 70, 219-226.
Nino, R.M.R.; Patino, R.J.M. Effect of the aqueous phase composition on the adsorption of bovine serum albumin to the air-water interface. Industrial and Engineering Chemistry Research 2002, 41, 1489-1495.
Antipova, A.S.; Semenova, M.G.; Belyakova, L.E. Effect of sucrose on the thermodynamic properties of ovalbumin and sodium caseinate in bulk solution and at air-water interface. Colloid and Surfaces B: Biointerfaces 1999, 12, 261-270.
Rouimi, S.; Schorsch, C.; Valentini, C.; Vaslin, S. Foam stability and interfacial properties of milk protein-surfactant systems. Food Hydrocolloids 2005, 19, 467-478.
Adebowale, K.O.; Lawalb, O.S. Foaming, gelation and electrophoretic characteristics of mucuna bean (Mucuna pruriens) protein concentrates. Food Chemistry. 2003, 83, 237-246.
Chandi, G. K.; Sogi D.S. Functional properties of rice bran protein concentrates. Journal of Food Engineering 2007, 79, 592-597.
Firebaugh, J.D.; Daubert, C.R. Emulsifying and Foaming Properties of a Derivatized Whey Protein Ingredient. International Journal of Food Properties 2005, 8 (2), 243-253.
Herceg, Z.; Rezek, A.; Lelas, V.; Kresić. G.; Franetović. M. Effect of carbohydrates on the emulsifying, foaming and freezing properties of whey protein suspensions. Journal of Food Engineering 2006, 79, 279-286.
