Use of auctions to assess consumer value for milk from different packaging

The objective of this study was to evaluate the effect of a sensory experience and educational message on consumer value for fluid milk in different containers: translucent high-density polyethylene (HDPE), white-pigmented HDPE (light-block), and paperboard. We carried out 11 auction sessions (n = 100). Sessions included an explanation of the experiment process; a survey about demographics and milk purchasing and consumption behaviors; a sensory evaluation; an educational message; and 3 rounds of nth price auctions. Consumers were blindly served 2 pairs of milk samples—2% milk from paperboard and translucent HDPE, and skim milk from paperboard and translucent HDPE—and asked to indicate their preference and level of acceptability for each, using a 7-point hedonic scale. Consumers were asked to ascribe a monetary value to each sample. Consumers were also asked to taste and assess a value for 2% and skim milk from light-block HDPE. All milk samples were evaluated simultaneously by a panel of 9 judges who were trained to evaluate milk quality attributes on a 15 cm unstructured line scale. All milk was from the same industry source, processed and stored on the same timeline for each session. Results from the consumer panel on acceptability, trained panel descriptive analysis and consumer bids were analyzed using multi-factor ANOVA. Subjecting responses to pre- and post-surveys to k means cluster analysis revealed 4 bidding populations in each round. Trained panelists detected higher levels of light-oxidized off-flavor in skim milk from translucent HDPE (5.8 cm) than from light-block HDPE (2.42 cm) and in 2% milk from translucent HDPE (5.1 cm) than from paperboard (0.32 cm). Although 84% of participants regularly purchased milk in plastic containers, consumers' acceptability scores for milk of the same fat content but from different packaging were not different. However, consumers gave higher acceptability scores to 2% milk from paperboard (5.2/7.0) than skim milk from paperboard (4.7/7.0). We found no differences in consumer value (US$) for 2% or skim milk in paperboard or translucent HDPE. However, after consumers received an educational message and tasted “Certified Fresh Taste” samples, they were willing to pay more for 2% milk in paperboard ($0.31 more) or HDPE ($0.38 more) packaging with a “Certified Fresh Taste” seal and for skim milk in paperboard ($0.15 more) or HDPE ($0.21 more) packaging with a “Certified Fresh Taste” seal than for milk in packaging without such labeling. Although consumers could not detect a difference in the milk from different packages, they indicated that they would pay more for a “Certified Fresh Taste” seal after hearing about the effects of light on milk in different packaging, demonstrating the importance to consumers of external cues about freshness.