Effect of moisture content on crackability of bambara groundnut using a centrifugal cracker
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Date
2007-04-17
Authors
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Journal ISSN
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Publisher
Institute of Agrophysics, Polish Academy of Sciences
Abstract
One of the most tedious operations in processing
bambara groundnut is the shelling operation. However, moisture
content normally affects the handling and processing of agro materials, such as nut shelling/cracking. This study was conducted
to determine the effect of moisture content on shelling efficiency of
bambara groundnut using a centrifugal cracker. A 50 kg bag of
bambara groundnut obtained from Damboa Local Government
Area of Borno State, Nigeria, was divided into three groups. These
groups were prepared for tests by soaking them in ordinary water at
room temperature for different periods of 0, 60 and 90 min to obtain
different levels of moisture content. Moisture content of each
sample was determined by oven drying at 130°C for 6 h. The
moisture content levels were found to be 5.3, 9.6, and 12.2% (d.b.)
for samples A, B and C, respectively. The samples were subjected
to impact energy through a centrifugal impaction device operating
at an angular velocity of 1920 r.p.m., using three different types of
impellers. Data obtained on the percentage of fully shelled pods
and unbroken seeds, fully shelled pods with broken seeds, partially
shelled pods and unshelled pods were statistically analysed.
Results showed that both moisture content and impeller angula tions have a significant effect on these performance indices. The
most effective performance was obtained at moisture content of
5.3% (d.b.), at which the shelling efficiency, percentage of dama ged seeds, percentage of partially shelled pods and percentage of
unshelled pods were 96, 3.4, 0.6 and 0, 86.6, 3.6, 5.6 and 4.2, 85,
2.4, 5.4, and 7.2% for the forward facing impeller, radially posi tioned impeller and the backward facing impeller, respectively.
The study further showed that development of a centrifugal impact
bambara groundnut sheller with winnower would eliminate the
tediousness of the present manual pod cracking methods.