Protein content can range from 25 to 50%, the most common being between 30 and 40%. Oil content ranges from 13 to 25%, the range for commodity soybean is of 16 - 23%.
Market requirements for soybean centers on the physical appearance and contents of foreign material, this also includes breakage of soybean seeds. Breakage of seeds will increase by each handling, particularly when moisture content is low.Foreign material content will adversely affect the storability and the aeration/drying efficiency, and if not removed prior to processing, quality of both oil and protein meal.
In general, moisture content is not part of the quality determining factors, but is information of importance for official inspections. The management of moisture specification and storage is important to long term storage of soybeans. The range of moisture content recommended depend on the end use of the beans. Below 11% is recommended for direct food use. For extraction of oil, 12,5-14% is recommended for beans to be extracted within 12 months. Moisture content above 13% is not recommended as it will affect storage ability and often results in quality deterioration within short time. If climatic conditions upon harvest are humid, the newly harvested seeds might have moisture rates of 18-19%, and it is of great importance that a drying process is started immediately in the storage facility and finished in a couple of days. Moisture content above 14% can open up for growth of fungi such as Aspergillus flavus making the seeds useless.