The need for high quality corn is continuing to increase in the Midwestern United States. This is especially true for high value specialty corn hybrids such as food-grade white corn. Corn of high quality is essential for end users producing products such as corn chips, tortillas, masa flour, and breakfast cereal. High quality corn should be low in stress cracks and have a low, uniform moisture content. Stress cracks are one of the most troublesome types of corn damage caused by improper drying and cooling.
Stress cracks are fine cracks in the endosperm of the kernel, located just below the surface.
Kernels with a large number of stress cracks are more susceptible to breakage, yield smaller grits during dry milling, absorb water too rapidly during wet milling, and are more susceptible to insect and mold damage during storage. However, this background level of stress cracking is greatly increased during post-harvest handling. High drying and cooling rates are the major factor in stress crack development. When moisture is removed from the kernel too quickly, the structure of the kernel fails and stress cracks form. In order to maintain quality, and therefore maximize premiums, producers must strive to minimize the increase in the number of stress cracks caused by drying and cooling.