Effect of Storage Conditions and Soybean Variety on Mineral Composition of Soybean Grains

Post-harvest losses are largely driven by insufficient storage methods, which compromise grain quality and nutritional value, exacerbating food insecurity and economic waste. In Tanzania, most storage-related losses are attributed to the use of inadequate storage materials and practices in general. The study aims to determine the influence of soybean variety (SC Semeki and Uyole soya 2), storage temperature (15°C and 25°C) and material (polypropylene and Purdue Improved Crop Storage (PICS) bags and polypropylene bags) on mineral profile (Calcium, potassium, magnesium, manganese, phosphorus, iron, copper and zinc) for period of 3 months. The results revealed that the highest level of decrease in varieties was observed with SC Semeki (maximum decrease 49%) compared to Uyole soya 2 (38%). With storage material, polypropylene bags (49%) had higher decrease compared to PICS bags (maximum decrease 29%). While, with temperature 25°C (maximum decrease 42%) had higher decrease in comparison to 15°C (maximum decrease 38%). In addition, the relationship between factors and mineral profile (R square) revealed highest variation in iron (99%), copper (98.7%) and calcium (82.8%), while the least with potassium (46.8%). However, general findings in mineral composition during storage showed that the least decrease was with iron (maximum decrease 5%) and the highest was with calcium (maximum decrease 49%). These findings underscore the efficiency of PICS bags and low temperature storage while acknowledging the variation in sensitivity of mineral profile with soybean variety.