Evidence for Kynurenine in Milk

Kynurenine, a potential precursor to o-aminoacetophenone in dry and sterile concentrated milks, was found to be a constituent of fresh milk. Employing alkaline degradation studies on the basic fraction of milk serum, obtained by negative pressure dialysis and ion exchange extraction, concentration of kynurenine was found to be in the order of one μM per liter of raw milk serum. Evidence is presented to show that the concentration of kynurenine in milk serum decreases as the original milk is heated at temperatures exceeding 93.3C for 15sec.