For classing purposes, bleached Tannin sorghum must have a pigmented testa which shows a dark color and area of coverage on the back of the kernel (singularly or in combination) equal to or greater than shown.
Do Not Prorate Area Of Coverage.
Illustration shows from left to right:
Kernel A: Bleached Tannin (brown seed coat).
Kernel B: Bleached Tannin (white seed coat).
Kernel C: Cross-sectioned Tannin Kernel, dark testa layer and white starch.
Kernel D: Cross-sectioned weathered sorghum, shows absence of testa layer and Kernel D: purplish/creamy appearance.
Note: Sorghum kernels exposed to mold, insect, weather, or stress may exhibit similar dark spots depicted on kernels A and B. If this condition exists, it may be necessary to cross-section a questionable kernel to verify it is Tannin.