Use of Solar Energy for Disinfesting Stored Dates

Abstract

A solar heat exposure or solarization trial was carried out
during November 2007 at Shambat Research Station, Sudan. The
Objective of the study was to control the date moth Ephestia calidella
(Guen.) and the saw-toothed grain beetle Oryzaephilus surinamensis (L.)
in stored dates. Black iron and polyethylene solar heat collectors were
constructed and exposed to the sun. The results showed considerable
variation in the mean temperature between the iron heat collector,
polyethylene heat collector and control treatments; they were 41.5C,
53.7C and 57.4C, respectively, while the ambient mean temperature and
relative humidity were 33C and 52.9%. Six and 12 hours were enough
to control E. calidella in the iron heat and polyethylene heat collectors,
respectively, and 18 and 24 hours to control O. surinamensis. Exposing
the ripened dates to a mean temperature of 57.4C for 24 hours did not
lead to high significant change in the chemical composition, except that
some sucrose was inverted to reducing sugars.