Rancid Flavor of Milk: Relationship of Acid Degree Value, Free Fatty Acids, and Sensory Perception

Acid degree value (ADV) as determined by the standard method, free fatty acid profile, and sensory analyses by a trained panel (n = 5) using magnitude estimation were used as measures of intensity of rancid flavor in milk. The correlation between ADV and rancidity scores was 0.13 (p = 0.16). Laboratory‐prepared rancid samples were assigned higher rancidity scores than farm‐collected milk samples with similar ADV. Rancidity scores and ADV increased with storage time. Major free fatty acid concentrations increased as ADV increased (r = 0.93, p = 0.0001) for farm milk samples but correlation was low (r = 0.27, p = 0.40) for laboratory‐prepared rancid samples.