Milk has almost a neutral flavor profile that is pleasantly sweet, with no distinct aftertaste. The flavor is imparted by the natural components such as proteins, fat, salts, milk sugar (lactose), and possibly small amounts of other milk components. Whole milk has 3.5% milkfat, lowfat milk 1-2%, and skim, <0.5%. Fluid milk composition and flavor variations have been attributed to types of feed, seasonal variation, breed, milk handling, storage conditions, processing, and packaging. Therefore, the sensory evaluation of milk, in both the bulk and packaged forms, is of utmost importance to the market (fluid or beverage) milk industry. The per capita fluid milk sale in the U.S. is about 79.61 L (IDFA, 2006). Since fluid milk is consumed regularly by people of all ages and most ethnic groups, this product is constantly being assessed for quality by consumers. If the flavor of milk is not appealing or appetizing, less of it will be consumed. Furthermore, off-flavored milk may cast an unfavorable reflection on other dairy products that are sold or distributed under the same brand name and thus unfavorably affect sales of those products as well. The sensory characteristics of any dairy product are most dependent on the quality attributes of the milk ingredient(s) used to produce them. An important truism of the dairy industry is that "finished milk products can be no better than the ingredients from which they are made." The quality and freshness of the various milk and cream components is most critical to product sales. Most flavor defects of finished dairy products could be substantially minimized, or perhaps eliminated, if all dairy manufacturers would more critically assess the essential quality parameters of all ingredients, especially the milk-based ones. The differentiation of milk into different quality classes (known as grading) demands keener, more fully developed senses of smell and taste than does the sensory evaluation of other dairy products. Many of the off-flavors present in fluid milk are more delicate, less volatile, or otherwise more elusive than those typically encountered in other dairy foods. Since milk (or cream) is the basic material from which all dairy products are made, it behooves milk producers, dairy processors, distributors, and other personnel involved with dairy products to be aware of how various flavor defects of milk affect the quality of manufactured products. Processing personnel should have the ability to detect off-flavors in milk and be able to assess or project the impact of these on the flavor quality of finished dairy products.
Alvarez, V. B. (2009). Fluid milk and cream products. In The Sensory Evaluation of Dairy Products (pp. 73–133). Springer US. https://doi.org/10.1007/978-0-387-77408-4_5