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The objective of this study was to fortify 50% reduced fat Cheddar cheese with n-3 fatty acids and evaluate whether this fortification generated specific off-flavors in the cheese. Docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acids were added to the cheese to obtain 3 final fortification levels [18, 35, and 71 mg of DHA/EPA per serving size (28 g) of cheese] representing 10, 20, and 40% of the suggested daily intake level for DHA/EPA. The presence of oxidized, rancid, and fishy flavors as a function of fortification level and cheese aging (6 mo) was evaluated using a sensory descriptive panel. No differences were found in the oxidized and rancid flavors as a consequence of DHA/EPA fortification, with only slight intensities of these flavors. The presence of fishy off-flavor was dependent on the fortification level. Cheeses with low fortification levels (18 and 35 mg of DHA/EPA per serving size) did not develop significant fishy off-flavor compared with the control, whereas at the highest fortification level (71 mg of DHA/EPA per serving size) the fishy off-flavor was significantly stronger in young cheeses. The fishy flavor decreased as a function of age and became nonsignificant compared with the control at 3 mo of storage. Even though fishy flavors were detected in the fortified cheeses, the DHA/EPA content during storage remained constant and complied with the suggested values for food fortification. Results obtained from this research indicate that 50% reduced-fat Cheddar cheese aged for 3 mo can be used as a vehicle for delivery of n-3 fatty acids without generation of off-flavors.

This study assessed the effects of three emulsified systems on taste thresholds and the near-threshold taste intensities of the five tastes (sweet, sour, salty, bitter and umami). Emulsions were formulated with different lipid chemical compositions. Lipid addition in an emulsified form significantly increased thresholds for sour and bitter tastes produced by citric acid and quinine hydrochloride, respectively. No significant differences were found in the threshold levels in emulsions formulated with different lipids for the five tastes evaluated. In general, for the same tastant concentration, taste intensities for sour and bitter tastes were lower in emulsions compared with the aqueous solutions, which is related to the higher threshold observed in the emulsions. On the other hand, the presence of a lipid phase increased the perception of umami and saltiness, with higher intensity values observed in the emulsions. Finally, lipid addition did not affect sweet intensities. These results suggest that, depending on the type of tastant used, the presence of a lipid phase in an emulsified form may alter the sensory perception of foods. Further research needs to be made for specific products to evaluate the effects of specific ingredients on the sensory properties of foods. PRACTICAL APPLICATIONSConsumers are aware of the health consequences associated with their diets. Current tendencies of incorporating a healthy diet in consumers' everyday lives have challenged food manufacturers to produce foods with improved nutritional qualities while maintaining their sensory characteristics. Some of these improvements include the formulation of low-sodium, low-carbohydrate 1 Corresponding