Consumer perception and sensory effect of oxidation in savory-flavored yogurt enriched with n-3 lipids

The objective of this study was to determine the effects of different oils (butter, fish, and oxidized fish) on sensory characteristics of a savory [chile-lime (CL)] low-fat yogurt using descriptive (unstructured line scales, 5 attributes) and affective (hedonic) sensory testing methods. Yogurts were each manufactured at low [1.1-1.2% total fat; 0.43% added oil (wt/wt)] or high [1.6% total fat; 1% added oil (wt/wt)] levels of fish oil, with high levels of fish oil targeted to deliver 145 mg of docosahexaenoic acid+eicosapentaenoic acid/170 g of yogurt. In a preliminary study, untrained panelists (n=31), using triangle tests, did not discriminate between low levels of fish and butter oils in unflavored yogurts but could discern yogurt with oxidized fish oil, even at the low level. Trained panelists (n=12) described lower lime and acid flavor characteristics in CL-flavored yogurts containing 1% oxidized fish oil compared with yogurts containing low levels of oxidized fish oil and low or high levels of butter and fish oils. Oxidized flavor was higher in CL-flavored yogurts with oxidized fish oil (low and high) and with the high level of fish oil. Consumer ratings (n=100; 9-point hedonic scale; 9="like extremely) of overall acceptability and flavor acceptability were bimodally distributed, with overall means between 4 and 5 ("neither like nor dislike") for CL-flavored yogurt with butter or fish oils (high level). The upper 50% of responses for yogurt with butter or fish oil were 6.51 and 6.31, respectively, for overall acceptability ("like slightly"), and 7.02 and 6.56, respectively, for flavor acceptability. A large segment of consumers may be interested in incorporating heart-healthy n-3 lipids in their diets through frequent consumption of a savory yogurt enriched with n-3 fatty acids.