Shelf Life Prediction and Storage Stability of Deglet Nour Dates (Phoenix dactylifera L.): Microbiological and Organoleptic Properties

Deglet Nour dates (Phoenix dactylifera L.) were sorted out according to the UNECE DDP-08 standard concerning the marketing and commercial quality control of dates. Desorption isotherms at 5, 30 and 40 degrees C and the Guggenheim-Anderson-deBoer (GAB) sorption model were used to estimate proper storage conditions and to predict shelf life. Physicochemical, organoleptic and microbiological analyses were performed initially on fresh and stored dates (18% db) packaged with polyethylene film at 5 degrees C and 85% relative humidity (RH). The moisture content affording the longest time period with minimum quality loss was predicted to be 17.44% on dry matter basis (db). The total heat of desorption needed for drying fruits was calculated to be 16.48 Kcal mol(-1). Fruit was microbiologically stable after 154 days storage period. The sensorial analysis showed that the color, the odor and the taste did not change significantly during storage. Critical moisture content was predicted to be 26.5% (db). This value is smaller than what the UNECE DDP-08 codex, allows for commercial whole dates (30% db).