Variability of physicochemical properties of ‘Deglet Nour’ date fruits collected from different oases in Djerid Region, Tunisia

Purpose : Quality and physical characteristics of date palm changes during growth and maturation stages of fruits in main production areas in the south of Tunisia. Research Method: The effect of season, ripening date and climatic conditions (temperature and relative humidity) on physicochemical characteristics of fresh dates “Deglet Nour” grown at four different oases were evaluated using multivariate analysis. Main findings: Dates from Traditional Mountain Oases (TMO) had the highest values of length, width, weight, moisture content for the two seasons. Those from Modern Palm Plantation (MPP) had the highest values of fiber content, water activity, glucose and fructose in 2014. In 2014 and 2015, date palm fruits of Modern Continental Oases (MCO) had the highest values of sucrose. The lower values of the different parameters were registered for dates from Traditional Continental Oases (TCO). Meteorological data from the experimental station recorded higher temperature and relative humidity during fruit maturation (July, August and September) in 2014 compared to 2015. Results showed that the good quality of dates was obtained in oases TMO that had higher relative humidity and lower temperature compared to other oases (MPP, MCO, and TCO). Such changes may have resulted from earlier pollination and higher temperatures during the maturation period. Considering the two seasons 2014 and 2015, the highest thermal coefficients were observed in MCO (3726 and 3704, respectively) and the lower ones in TCO (3083 and 3025, respectively). Research limitation: No limitations were founded. Originality/Value: Seasons and oases climate significantly affected the physical and biochemical quality characteristics of date palm fruits. This engendered in the longest maturity period recorded in TCO. MPP where we recorded the highest spring temperatures, showed the shorted development cycle.