Principles of Biochemistry

6.4.5.5 Thiobarbituric acid Value (TBA Value)

The 2-thiobarbituric acid (TBA ) reaction has been widely used to determine rancidity. There is direct distillation of carbonyls and other reactive substances from acid media that yield a red colored compound upon heating with TBA reagent, which is measured spectrophotometrically. The TBA- reactive substances provide an indication of the fat quality. If the value exceeds 1-2µ mole malonaldehyde/g of fat, the fat is considered as rancid.