THE INFLUENCE OF FAT ON THE SENSORY PROPERTIES, VISCOSITY, AND COLOR OF LOW-FAT MILK

A sensory panel was trained to assess appearance, aroma, flavor, and t extural attributes of milk containing various percentages of fat. The relative viscosity and color of the milk were also measured. Milk appe arance had a profound effect on the perceived mouthfeel. There was a c orrelation of the L-value (whiteness), a-value (greenness), and b-valu e (blueness) for the milk with the perceived color and mouthfeel. As f at content was increased, the milk was whiter, less green, and less bl ue. Similarly, sensory scores for appearance and mouthfeel attributes increased as fat content increased from 0 to 2%. Panelists were given the samples under red lighting to mask the milk color. Under these con ditions, the perceived mouth coating, residual mouth coating, and thic kness of 2% fat milk were decreased from those of the same samples tes ted under normal light. Our results suggested that a fat substitute fo r fat-free milk needs to change the appearance more than the tactile a ttributes of the milk. A successful fat substitute should alter the co lor of fat-free milk such that the L-, a-, and b-values are approximat ely 81, -3.7, and 2.9, respectively, based on L-, a-, and b-values of 74, -6.7, and 1.1 for skim milk.