We found that wheat bran acted as a nitrite scavenger under conditions similar to those that exist in the stomach. Wheat flour and cellulose did not act as nitrite scavengers. Wheat bran, at a concentration equivalent to that in the stomach after ingestion of about two pieces of whole-wheat bread, reduces the nitrite concentration from 20 microM to about 10 microM in 60 min at pH 3.5 and 37 degrees C. At pH 2.5 and 1.5, most of the nitrite had disappeared in 10 min. At pH less than or equal to 2.5 the nitrite scavenging effect of bran was as efficient as that of ascorbic acid. Ferulic acid, a component of bran, reacted rapidly with 20 microM-nitrite both at pH 3.5 and 1.5, whereas phenolic lignin model compounds only reacted at pH 1.5.