S: Sensory and Nutritive Qualities of Food
Preference Mapping of Commercial Chocolate Milks
J.L. T HOMPSON, M.A. DRAKE, K. LOPETCHARAT, AND M.D. YATES ABSTRACT: The dairy beverage market is a competitive and growing category in the food industry. Within this arena, chocolate milks vary widely in flavor, color, and viscosity. Understanding what sensory properties drive consumer likingis critical for maximum market share. This study was conducted to identify and define sensory characteristics of commercial chocolate milks and to link these differences to consumer preferences through the application of internal and external preference mapping. A sensory language was identified to document the sensory properties (visual, flavor, mouthfeel) of chocolate milks. Twenty-eightcommercial chocolate milks were subsequently evaluated by descriptive sensory analysis using the identified sensory language. Thirteen representative milks were chosen for consumer acceptance testing followed by internal and external preference mapping to identify key drivers. Instrumental color and viscosity measurements were also taken. Two different techniques were used for external preference mapping:cluster analysis with generalized procrustes analysis and landscape segmentation analysis. Chocolate milks were differentiated by descriptive sensory analysis (P < 0.001). Wide variability was also observed in consumer acceptability of chocolate milks (P < 0.001). Correlations were observed among descriptive and consumer, descriptive and instrumental, and instrumental and consumer results (P <0.001). Generalized procrustes analysis revealed 2 groups of consumers with 1 nondistinguishing driver of liking: cocoa aroma. Landscape segmentation analysis confirmed and clarified generalized procrustes analysis results by identifying 3 consumer segments with 3 drivers: cocoa aroma, malty, and cooked/eggy flavors. Keywords: preference mapping, chocolate milk, milk, sensory analysis, acceptabilityIntroduction
reference mapping is a commonly used tool in understanding the descriptive sensory attributes that drive consumer preferences (Schlich 1995; McEwan 1996). The procedure requires an objective characterization of product sensory attributes, achieved by descriptive analysis, which is then related to preference ratings for the product obtained from a representative sample ofconsumers (Murray and Delahunty 2000). Internal preference mapping uses only consumer data to determine consumer preference patterns, whereas external preference mapping relates consumer preference data to descriptive sensory information and/or instrumental data (Lawlor and Delahunty 2000). These techniques can guide product optimization and development (McEwan 1996). Both internal and external preferencemapping techniques have been implemented in a number of studies with a variety of products (Hough and Sánchez 1998; Yackinous and others 1999; Richardson-Harman and others 2000; Young and others 2004). The beverage market is a competitive and growing category in the food industry. Flavored milk beverages offer specific benefits including flavor and nutrition. School children are more likely todrink milk and reach dietary requirements when offered chocolate milk at school (Garey and others 1990). There has been limited research on chocolate milk itself. A recent study by the American Dairy Council and the American School Food Service Assn. revealed that offering flavored milks was 1 way to increase milk consumption among children (Anonymous 2003). Chocolate is the
MS 20040288 Submitted5/4/04, Revised 8/3/04, Accepted 8/6/04. The authors are with Dept. Food Science, Southeast Dairy Foods Research Center, North Carolina State Univ., Raleigh, NC 27695-7624. Direct inquiries to author Drake (E-mail: firstname.lastname@example.org).
most popular milk flavor and represents a popular option among children and adults. Within this arena, commercial chocolate milks vary widely in flavor,...