Separation and estimation of diacetyl and acetoin in milk

Abstract

SummaryTwo methods are described for the separation of diacetyl and acetoin in milk by steam distillation. In the first method, acetoin is measured in the residue remaining in the extraction flask after steam distillation while diacetyl is measured in the first 10 ml of distillate which contains 35% of the acetoin and 100% of the diacetyl. Increases in the volume of residue taken for analysis decreased colour development by acetoin. In the second and preferred method, diacetyl is measured in the first 10 ml of distillate and acetoin in the second 10 ml of distillate which contains about 24% of the added acetoin. Diacetyl in both methods is measured by a modification of the method of Prill & Hammer (Walsh & Cogan, 1974) and acetoin by the Westerfeld (1945) procedure.