Physicochemical Characteristics of Date Sap Lagmi from Deglet Nour Palm (Phoenix Dactylifera L.)

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.