Miller Magazine Issue: 141 September 2021

78 ARTICLE MILLER / september 2021 or homogenizes varying moisture contents of a grain bulk. Improving of Postharvest Management Storage management is responsible for maintaining the quality of the grain before processing and for keep- ing any losses to a minimum. Common techniques in- clude aeration, fumigation and moving the grain to avoid any heat, insect or fungus damage. When aerating the grain, temperature and relative humidity of the ambient air must be observed to avoid or minimize damage of the grain. This is difficult to achieve at harvest time when it is warm or humid. Grain cooling con- servation, being independent of the weath- er, represents an easier option and does not lead to a degradation of the grain quality. Taking a look on fumigation leads to several constraints for an easy postharvest manage- ment. Adequate protection of human health and of the environment is a must if fumigation is applied. A sealed storage facility is required or regular re-gassing is unavoidable but could lead to developing a resistance to a number of fumigants at low effectiveness. Grain cooling is safer and easier than using fumigants. Moving grain is sometimes used to deal with the issue of hot spots in grain caused by in- sects and fungal infestation. This requires investment in equipment for additional stor- age capacity and transport equipment, incurring labor and energy costs. The man- agement must also be able to react quickly and effectively. This technique is applied for many grains but leads to as grinding losses of up to 0.06 % caused by the conveyor equipment (Boac, 2010) for each turn. When grain cooling is applied no moving of the grain is required at any time which spares cost and losses. Improving of grain processing by grain cooling The effect of grain cooling should not be limited to the storage when it is applied but needs to be observed into grain processing. The milling of grain is done by grinding the kernel to flour. The process is done in a highly efficient way but depends on the grain quality and its homogeneity. Therefore grain is graded or sorted before processing. The more homogeneous the grain is the higher the efficiency. When grain is cooled it remains as harvested and there is Fig 2: Application of grain cooler at warehouse (FrigorTec, 2008) Fig 3: Heat generation during grain storage modified according to Jouin (1964)