Changes in soybean quality under controlled environmental conditions using static grain respiration measurement system

Grain quality evaluation during storage has become an important field of study to control postharvest losses. Lipid oxidation (LO) and dry matter loss (DML) are considered the main causes of deterioration in quality due to its impact on chemical, sensorial and nutritional properties of soybeans. Prolonged storage time during unfavorable conditions, such as high temperature and moisture content, is responsible for accelerating LO and DML rates (vv_DML). To understand changes in soybean quality, storage tests were performed by placing 22% moisture content soybeans in two different sealed chambers at 30°C for 40 days. DML was quantified by measuring respired carbon dioxide (CO2, ppm). This measurement was used to calculate mass of respired CO2 (g CO2/kg beans d.b.) and correlated with DML. To obtain information about the oxidative process, samples were collected every 5 days for further chemical analyses. The objective was to quantify changes in quality of soybeans under adverse storage conditions. In addition, an alternative approach to measure DML using a static grain measurement system (S-GRMS) was evaluated. Data and samples collected, as well as the improved S-GRMS, will be important to design further experiments to estimate quantitative and qualitative grain losses during storage. Results of future experiments will be essential for understanding deterioration processes in soybean and building guidelines to prevent postharvest losses.