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Canning -- Vegetables
What causes the gray-black particles that sometimes appear in canned corn?
The best guess is that some mineral in the corn is at greater than usual concentrations and the heat processing and possibly some pH interaction are leading to a pigment change. This is more likely to occur when the corn is grown under stress conditions (like drought). It may be iron, sulfur or some other mineral. The product is safe to eat but probably won't be used because the discoloration is not very appetizing. Several cases in Missouri were reported when using the variety, Royal Delight; so it may be varietally related also. PREPARED BY: Angela M. Fraser, Ph.D., Associate Professor/Food Safety Specialist, and Carolyn J. Lackey, Ph.D., R.D., L.D.N., Professor/Food and Nutrition Specialist, North Carolina State University (August 2004)