Chilling and Freezing Storage for Keeping Overall Quality of “Deglet Nour” Dates

The effect of storage at ۰ and ۲۰°C for ۳۰ days with and without a passive Modified Atmosphere Packaging (MAP) and the effect of a freezing storage at -۲۰, -۴۰ and -۸۰°C for ۱۰ months followed by ۱ week at ۵°C on overall quality of Deglet Nour dates were studied. After the storage time, the physicochemical properties and sensory quality, microbial development, and moth infestation (Ectomyelois ceratoniae) of dates were monitored. It was observed that the storage temperature greatly affected the overall quality of dates. The ۰°C was recommended for a short-term storage of fresh dates of one month. The MAP technique (۶ kPa O۲+۱۲ kPa CO۲) showed a positive effect on keeping overall quality of dates at ۲۰ºC. However, for a long-term storage (۱۰ months in frozen conditions plus ۱ week at ۵ºC), all freezing temperatures assayed kept the overall quality of dates and no differences were observed among them. In order to minimize the global costs, -۲۰°C was considered as the most adequate temperature for a long-term freezing storage period. In conclusion, these chilling and freezing techniques could be recommended for commercial use at industrial scale.

Keywords:

Cold storage , Commercial life , Date palm , Ectomyelois ceratoniae , MAP technique.