17B-8 |
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J. GALLAHER, C. P. Chee, J. N. Coupland, R. Hollender, D. G. Peterson, and R. F. Roberts. Dept. of Food Science, Pennsylvania State Univ., 126 Borland Lab., University Park, PA 16802 The current Western diet contains inadequate levels of n-3 polyunsaturated fatty acids (PUFA) which may be of great importance as these lipids have been linked to beneficial effects on neural and visual development and the prevention of numerous diseases. An enriched food product containing a physiologically significant amount of n-3 PUFA and acceptable sensory characteristics could provide a useful source for consumers to increase their consumption of these lipids. However, enrichment of foods with n-3 PUFA is difficult because these unsaturated fatty acids are highly susceptible to rancidity. The goal of the research was to evaluate the oxidative stability of set-style strawberry flavored yogurt prepared using an algae oil-in-water emulsion delivery system. An algae oil (~40% n-3) emulsion prepared at the University of Massachusetts was added either before or after homogenization to a yogurt mix to achieve a nutritionally significant 500 mg of n-3 PUFA per serving of yogurt (272 g). The mix was flavored with a strawberry fruit base, fermented to pH 4.6, and stored at 4ºC for 21 d. Oxidative deterioration was assessed at intervals by chemical (lipid hydroperoxides) and sensory (trained and consumer panels) methods. Both n-3 enriched yogurts increased in lipid hydroperoxide concentration at a similar rate and to a greater extent than control yogurts containing no added n-3 PUFA. However, the trained panel was only able to distinguish the "fishy" taint in the sample supplemented with n-3 PUFA before homogenization after 21 days of storage. The consumer panel on the other hand rated all products as moderately liked, and was unable to distinguish supplemented samples from control. These results suggest that it is possible to make an n-3 enriched yogurt that has acceptable sensory characteristics and that the strawberry flavoring system may have a masking effect on the "fishy" flavor produced by n-3 PUFA oxidation.
Session 17B, Dairy Foods: General
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