Tannic acid content in sorghum (Sorghum bicolour M.): effects of processing

Some simple treatments were employed to reduce the tannin content in locally consumed sorghum grain. The treatments included overnight soaking of sorghum in 2% NaHCO3, soaking in different alkalis, ammoniation and autoclaving. Of the above treatments, ammoniation was best for complete removal of tannins. Soaking the seeds in alkalis was also effective. Soaking the sorghum seeds for 18 hours in mixed salt solution (containing 1.5% NaHCO3 + 0.5% Na2CO3 and 0.75% citric acid in w/v ratio) was also found to be effective.