Nixtamalized corn flour — produced by alkaline cooking of maize — is generally classified under heading 1102 as corn flour if it is finely ground, but CBP has examined whether the nixtamalization process transforms the product sufficiently to warrant a different classification. Importers of masa harina should review applicable CBP rulings and consider requesting a binding ruling, as the classification affects both duty rates and FDA labeling obligations.

Key commercial distinctions include particle size (flour vs. meal vs. grits), moisture content, color (white vs. yellow maize), and whether the product is conventionally milled or nixtamalized. Organic certification and non-GMO status are increasingly specified by food manufacturers. These attributes should be clearly documented in the commercial invoice and product specification sheet to support correct classification and FDA compliance.