The effect of airtight storage on sorghum grains quality [Sudan]

The success of airtight storage of dry or damp grain depends on the depletion of oxygen (O lower 2) in a sealed container to a lethal level for insects, molds and mites. This depletion of oxygen can be done naturally by respiration of living organisms and grain itself, or artificially by inducing inert gases, e.g. carbon dioxide (CO lower 2) and nitrogen (N lower 2) into a totally sealed structure. This study was conducted to evaluate the effectiveness of airtight storage (hermetic storage) in controlling Tribolium spp. and preserving and retaining sorghum grain quality during storage. The study was conducted for a whole year with special emphasis on the effect of sorghum initial moisture contents and presence of broken kernels on sorghum quality during storage in sealed "airtight" and open containers. The grains quality was measured with respect to insects population and their damege, bulk density, loss in total sound weight, grain germinability, fungal infection and grain biochemical changes. The numbers of alive insects in sorghum grains stored under hermetic conditions were found to be zero after a short time, regardless of the grain initial moisture contents and whether the grains were sound or contained brokels. Also, sorghum grain stored under this method retained significantly lower loss in total sound weight and higher bulk density compared to open storage conditions. The highest germination capacity was observed in sorghum grain with low initial moisture content, irrespective of the storage conditions. The germinability of sorghum grains with high moisture content was reduced to a greater extend in airtight conditions than in open conditions. The high initial moisture content of grain stored under hermetic conditions retairned significantly lower fungal infection than under open conditions at the end of the storage period, regardless of the presence of insects or broken kernels. Low initial moisure grains stored under both storage conditions did show large variation in moisture content during the storage period. The biochemical changes in terms of fat acidity and Q - amylase activity were affected when sorghum grains of high moisture content stored under hermetic conditions compared to open conditions. Finally , it can be concluded that airtight storage is a very effective method for insect control; however, the effectiveness of airtight storage for preserving grainquality depends greatly on the initial moisture contents of grains.