71A-38 |
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K. ARYANA1, H. T. Barnes2, T. K. Emmick3, and P. McGrew1. (1) Dept. of Dairy Science, Louisiana State Univ. Agricultural Center, 115 Dairy Science Bldg., Baton Rouge, LA 70803-4400, (2) Applications Research & Technical Services Manager, Kemin Health, L.C., 600 E. Court Ave., Suite A, Des Moines, IA 50309, (3) Senior Application Research Associate II, Kemin Health, L.C., 600 E Court Ave, Suite A, Des Moines, IA 50309 Research indicates that lutein may help protect the eyes and skin from oxidative stress and harmful blue light. While dark green leafy vegetables, egg yolks, and corn are naturally rich in the carotenoid, dairy products are not good sources of lutein. The objective was to determine the impact of various levels of lutein on the physico-chemical, microbiological, and sensory characteristics of yogurt over its shelf life. Nonfat strawberry yogurts were prepared with 0, 0.5, 1.5, and 3.0 mg lutein per 6-oz 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, instrumental color (L*,a*,b*), sensory flavor, body texture, appearance, and color were studied at weeks 0, 1, 3, and 5 after product manufacture. Three readings were recorded per replication, and two replications were conducted. Data were analyzed by ANOVA using the Proc GLM of SAS. Significant differences were determined at α=0.05. Lutein did not impact viscosity, pH, syneresis, standard plate counts and coliform counts, sensory body texture, appearance, and color. Significantly (P < 0.05) higher flavor scores were obtained for yogurts fortified with 1.5 mg lutein per serving. Yogurts with lutein levels of 1.5 and 3.0 mg per serving had significantly lower L* (lightness) values compared to the yogurts with 0 and 0.5 mg lutein per serving. The interaction effect between levels of lutein and storage time was significant (P < 0.05) for a* (redness) values. Lutein levels remained above target throughout the five-week storage study. These results suggest that lutein is suitable for inclusion in functional yogurts. The skin and eye health benefits of lutein can easily be incorporated into yogurt to complement inherent nutritional properties.
Session 71A, Dairy Foods: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |