7 C.F.R. § 51.1565
Internal defects
Internal defects are defects which cannot be detected without cutting the potato. Some internal defects are listed in Table VII.
| Defects | Damage Maximum Allowed | Serious Damage Maximum Allowed |
|---|---|---|
| Occurring outside of or not entirely confined to the vascular ring | ||
| Ingrown Sprouts, Internal Discoloration, Vascular Browning, Fusarium Wilt, Net Necrosis, Other Necrosis, Stem End Browning | 5 percent waste | 10 percent waste. |
| Internal Black Spot | When the spot(s) are darker than the official color chip (POT-CC-2) after removing 5 percent of the total weight of the potato | When the spot(s) are darker than the official color chip (POT-CC-2) after removing 10 percent of the total weight of the potato. |
| Occurring entirely within the vascular ring | ||
| Hollow Heart or Hollow Heart with Discoloration | Area affected not to exceed that of a circle 1⁄2 inch in diameter in a potato 21⁄2-inches in diameter or 6 ounces in weight. 1 | Area affected not to exceed that of a circle 3⁄4 inch in diameter in a potato 21⁄2-inches in diameter or 6 ounces in weight.1 |
| Light Brown Discoloration (Brown Center) | Area affected not to exceed that of a circle 1⁄2 inch in diameter in a potato 21⁄2 inches in diameter or 6 ounces in weight.1 | Area affected not to exceed that of a circle 3⁄4 inch in diameter in a potato 21⁄2 inches in diameter or 6 ounces in weight.1 |
| Occurring entirely within the vascular ring | ||
| Internal Brown Spot and Similar Discoloration (Heat Necrosis) | Not more than the equivalent of 3 scattered spots 1⁄8 inch in diameter in a potato 21⁄2-inches in diameter or 6 ounces in weight.1 | Not more than the equivalent of 6 scattered spots 1⁄8 inch in diameter in a potato 21⁄2-inches in diameter or 6 ounces in weight.1 |
| 1 Note: Correspondingly lesser or greater areas in smaller or larger potatoes. | ||