| Abstract: | ABSTRACT: The impact of various levels of lutein on the physicochemical, microbiological, and sensory characteristics of yogurt over its shelf life was determined. Nonfat strawberry yogurts were prepared with 0, 0.5, 1.5, and 3.0 mg lutein per 170 g serving (20% overages were included to account for processing losses). The lutein was incorporated prior to homogenization of the yogurt mix. Stability of lutein, viscosity, pH, syneresis, standard plate counts, coliform counts, color (L*, a*, b*), and sensory evaluation (flavor, body and texture, and appearance and color) were measured at weeks 0, 1, 3, and 5 after product manufacture. The interaction effect between levels of lutein and storage time was significant for a* (redness-greenness) values. Lutein levels remained above target throughout the 5-wk storage study. Lutein did not affect viscosity, pH, syneresis, L* (lightness) and b* (yellowness-blueness) values, standard plate counts, coliform counts, flavor, body, texture, appearance, and color scores. These results suggested that lutein was suitable for inclusion in functional yogurts. The skin and eye health benefits provided by lutein can easily be incorporated into yogurt to complement inherent nutritional properties. |
