Question
I am developing semi-dry date fruit preservation techniques including use of modified atmosphere packaging. One issue we have encountered is sugaring in semi-dry dates. What effect does temperature have on development of sugaring spotting? (Z.D.)
Answer
Sugar spotting in dates is due to crystallization of sugars below the skin and in the flesh of soft date cultivars. Although it does not influence taste it alters fruit texture and appearance. Storage at recommended temperatures minimizes this disorder, which occurs mainly in cultivars in which glucose and fructose are the main sugars. Sugar spotting is accelerated by temperatures above 10C (50F) and by relative humidities below the equilibrium RH range of about 55 to 65% for dates. It can be reversed by gentle heating (steaming) of the sugared dates. For more information about postharvest requirements of dates, go to:
http://postharvest.ucdavis.edu/PFfruits/Date/
-Adel Kader