The Influence of Fat Substitutes Based on Protein and Titanium Dioxide on the Sensory Properties of Lowfat Milks¹

The following food-grade ingredients were evaluated as fat substitutes in skim milk: Simplesse^® Dry 100 (The Nutrasweet Company, Deerfield, IL), Litess™ (Cultor, New York, NY), whey protein concentrate, sodium caseinate, Dairy Lo™ (Cultor), and titanium dioxide. The addition of 3% Simplesse^® Dry 100 to skim milk gave milk an appearance that was similar to that of 0.5% fat milk, and mouthfeel was improved to be equivalent to that of milk containing about 1% fat, which is similar to previous results with NDM. Suspension of titanium dioxide in skim milk made the milk whiter, which resulted in improved sensory scores for appearance, creamy aroma, and texture. Skim milk containing titanium dioxide was slightly bluer and greener (i.e., lower b and a values, respectively) than 2% fat milk. Correspondingly, the skim milk containing titanium dioxide was rated lower than the 2% fat milk for visual hang up (a measure of how well milk coats the glass), creamy aroma, texture, and aftertaste. A fat substitute for 2% fat milk must impart not only the opacity and whiteness of fat but also make the milk less blue and less green. The impact of titanium dioxide on the sensory characteristics of skim milk demonstrated the importance of whiteness. There is clearly a need to develop a whitener for fat-free milk other than titanium dioxide to provide processors with an ingredient option that would improve sensory properties and provide a nutritional benefit.