Physical and nutritional quality changes of maize grains stored using different storage methods
Abstract
The effectiveness of the different storage technologies for maize grains under conditions of
smallholder farmers were tested at Makerere University Agricultural Research Institute
Kabanyolo (MUARIK). Two improved storage methods were used to store maize grains
conditioned to 13.5%, 15%, 17%, and 20% moisture content. These storage methods were:
Purdue Improved Crop Storage (PICS) bags and SuperGrain (SG) bags. These were compared
against the conventional woven polypropylene (PP) bags as the control. Grains were stored for a
period of 90 days. Physical and nutritional quality parameters were analyzed on a monthly basis
for 90 days. Temperature and relative humidity in PICS, SG and PP bag setups were monitored.
Moisture content, germination, grain damage and 1000-grain weight of maize grains stored in
hermetic bags remained nearly the same at end of storage as they were at the beginning.
Germination rate declined in the bags conditioned to 20% moisture by (7%-23.33%) where as in
the PP bags, grain quality significantly changed at the end of storage time. At three months, grain
damage reached 20-58% for grains stored in woven PP bag. Also, moisture content of grains
stored in PP bags decreased with respect to initial levels reaching 10.14-10.61% at the end of 90
days whereas moisture content of grains stored hermetically remained fairly the same at the end
of storage. 1000-grain weight of maize grains stored in PP bags dropped reaching 245.59-265g
corresponding to grain weight loss of 35.4-37.8% for 90 days. However, that of maize stored
hermetically remained fairly the same throughout the storage period. Ash content and crude fibre
content values were obtained in the range (1.08%-1.60%) and (2.63%-3.68%) respectively. In
conclusion, all the hermetic storage technologies tested were effective in maintaining the
physical and nutritional quality changes of the grains for three months, while substantial quality
deterioration occurred for grains stored in PP bags without any protection. Hermetic bags maintained moisture content of the grains whereas a fluctuation in the moisture content of grains
stored in woven PP bags occurred.