Several studies have shown that trypsin inhibitor (TI) negatively affects the growth performance of monogastric animals. These studies conclude that lower TI levels in animal feed led to better growth performance. With USB funding, we measured the trypsin inhibitor activity (TIA) of several hundred soybean meal (SBM) samples. Our research revealed that despite the easy detection of TI protein in most commercial SBM samples, these proteins had very little protease inhibitor activity, presumably due to heat treatment. SBM undergoes heat treatment to destroy protease inhibitors. Overheating, a common issue with roasting, can affect protein quality traits such as protein solubility and digestibility. Thus, we investigated the protein solubility and digestibility of many commercial SBM samples and their potential correlation with TIA. Traditionally, soybean meal protein solubility is assessed using a 0.2% potassium hydroxide (KOH) solution. However, the original method is cumbersome and time-consuming. We streamlined the KOH solubility assay procedure, standardizing the starting material amount, KOH concentration, extraction duration, and SBM particle size. As a result, we developed a more cost-effective and consistent protocol. This simplified procedure allows efficient determination of protein solubility indices across numerous samples. We used our modified approach to assess protein solubility in various SBM samples, including traditionally heat-processed, extruded/expelled, domestic, and imported ones. Our simplified method yielded results comparable to the original, labor-intensive procedure, showing differences in protein solubility in commercial SBM samples due to varying heat treatments. However, we did not observe any strong correlation between protein solubility index and trypsin inhibitor activity. Additionally, we developed a simple in vitro procedure to accurately predict the protein digestibility of SBM samples. Current methods for determining protein digestibility involve complex multi-component systems that simulate various physical and chemical processes. Using our modified assay, we determined the protein digestibility index of several commercial SBM samples. However, further refinements are required before our procedures can be routinely used for accurate measurement of SBM protein quality.