Effects of splits content on dry matter loss rates of soybeans measured using a static grain respiration measurement system

The objectives of this study were to compare the effects of 0% to 16% (w/w) splits content (x_s) of soybeans stored at 35°C and 18% moisture content (w.b.) on dry matter loss rates (v_DML) and to determine a splits multiplier (M_S) for soybeans stored at these conditions, similar to the damage multiplier (M_D) used in ASABE Standard D535 for shelled corn. Effects of percentage by weight splits (x_s) on M_S and safe storage time are expected to be greater than M_D for corn because soybeans are prone to cracking and splitting, lipid oxidation, and protein degradation, all of which lead to grain dry matter and quality losses. Results indicated that v_DML increased with increasing x_s, and the mean vDML was 1.5 times greater for samples with 16% splits than for samples with 4% splits. The M_S for soybeans was linearly correlated with x_s, decreasing from 1.0 to 0.60 for 0% to 16% splits, respectively. Soybeans appeared to be more sensitive to percent by weight splits than corn was to the presence of damaged kernels. In Standard D535, the M_D for corn only decreased from 1.0 to 0.8 when percent (w/w) damaged kernel content increased from 30% to 40%. In comparison, it should be noted that damage to soybeans was defined differently from damage to corn. This research is useful in defining M_S for 18% moisture content soybeans stored at 35°C under hermetic conditions. The procedures outlined in this article may be used in the future to more formally define a soybean M_S that covers a wider range of moisture contents, storage conditions, and possibly an M_D based on other factors included in the USDA definitions of damaged soybean kernels.