Mechanical dehulling of watermelon seeds-Factors affecting hulling and kernel breakage.

Watermelon seeds were subjected to fourteen
pre-treatments using different combinations
of water, sodium hydroxide, potassium
hydroxide, hydrochloric acid, sulphuric acid
and ethyl oleate to soften and weaken the hull
prior to dehulling. The pre-treatments employing
sulphuric acid-sodium hydroxide,
ethyl oleate-sodium hydroxide and hydrochloric
acid-sodium hydroxide, combinations
gave 80,79 and 79 percent hulling and 67,69
and 74 percent whole kernel yield respectively.
The kernels thus recovered did not
exhibit any change in acidity, pH, visual
colour, composition and had improved sensory
quality. Pre-dehulling moisture of 45+5
percent was found to be the optimum. It is
preferable to separate the kernels from the
dehulled material recycle the unhulled seeds
for complete dehulling.