--Introduction. Despite their high nutritional value, by-products of dates are valueless in Tunisia, an important date-producing country. Our study aimed at testing a method for recovering these products by means of extraction, starting from a date paste, of a clarified drink. Materials and methods. The process of pulp extraction adopted was inspired by a traditional method. A rough solution obtained from the dilution of date paste was treated with enzymes (pectinases and cellulases) and by tangential microfiltration. The chemical composition, physico-chemical characteristics and rheological characteristics of the clarified drink obtained were determined. Results and discussion. The extracted rough solution has a high sugar content. The use of both microfiltration and enzymatic treatment resulted in a juice that has little acid content, with relatively low viscosity and turbidity and with a flow behaviour comparable to that of any other fruit juice. Conclusion. By-products of dates can be transformed, by the means of the usual processes, into a pleasant and marketable drink.

This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n=0.783) to Newtonian behaviour (n∼1) from 10 to 50 °C respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50s(-1)). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups.