The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage "blah" and its earliness. This variety is characterized by its astringent taste and has never been studied extensively...The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage "blah" and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.展开更多
Coastal date palm cultivars are interesting through their soft dates, their abundant and earliest production than continental cultivars. Maintaining bio-diversity in Tunisian oases has become a subject of first intere...Coastal date palm cultivars are interesting through their soft dates, their abundant and earliest production than continental cultivars. Maintaining bio-diversity in Tunisian oases has become a subject of first interest in date palm cultivation in Tunisia. Coastal oases still retain a very rich and varied plant biodiversity in comparison with the continental oases, weakened by the mono cultivation of "Deglet Nour" cultivar. Study of soft date's composition can make there well known to date consumers, help to valorize there and to help of sustainability of coastal oases ecosystem. Fresh dates from 15 cultivars was collected, dried by 80 ~C in 20-24 h. Acidity was determinate by pH meter. Sugars were appreciated by enzymatic method. Ash and minerals was calculated by photometer and spectrometer. Chemical date composition study showed that coastal date palm cultivars are predominantly rich of carbohydrates, have a low quantity of sucrose which gives them an important dietary value. Their pH varies from 5 to 6, classifies them as the best date quality for fresh consumption. Their richness in Total Nitrogen Matters and total minerals makes them at almost the same level as the other date palm eultivars analyzed by different authors in different areas of date palm production. Mineral composition showed that these dates are K and P-rich and relatively poor in Na and Ca.展开更多
文摘The cultivar date Lemsi is well known in the coastal oasis of Tunisia for both its quality stage "blah" and its earliness. This variety is characterized by its astringent taste and has never been studied extensively. An osmotic dehydration treatment is necessary to improve the quality of the final product for maintaining its integrity. Thus, it is a preservation technique that is often used as pretreatment to obtain partially dehydrated fruit. In this experimental study, the cultivar date Lemsi were cut into cubes of 1 cm3 and were immersed in sucrose solutions of 50%, 60% and 70% at 20℃ for 0-240 min. The moisture content, the solute gain, the water loss and the ratio WL/SG are determined and discussed. The results deduced from this work have showed that sugar gain SG, water loss WL and the ratio WL/SG are increased with concentration of osmotic solution. Likewise, the osmotic dehydration treatment need to be followed of a convective drying to ensure the quality of the final product.
文摘Coastal date palm cultivars are interesting through their soft dates, their abundant and earliest production than continental cultivars. Maintaining bio-diversity in Tunisian oases has become a subject of first interest in date palm cultivation in Tunisia. Coastal oases still retain a very rich and varied plant biodiversity in comparison with the continental oases, weakened by the mono cultivation of "Deglet Nour" cultivar. Study of soft date's composition can make there well known to date consumers, help to valorize there and to help of sustainability of coastal oases ecosystem. Fresh dates from 15 cultivars was collected, dried by 80 ~C in 20-24 h. Acidity was determinate by pH meter. Sugars were appreciated by enzymatic method. Ash and minerals was calculated by photometer and spectrometer. Chemical date composition study showed that coastal date palm cultivars are predominantly rich of carbohydrates, have a low quantity of sucrose which gives them an important dietary value. Their pH varies from 5 to 6, classifies them as the best date quality for fresh consumption. Their richness in Total Nitrogen Matters and total minerals makes them at almost the same level as the other date palm eultivars analyzed by different authors in different areas of date palm production. Mineral composition showed that these dates are K and P-rich and relatively poor in Na and Ca.