15C-35 |
Monascus purpureus pigments as yoghurt colorants |
P. E. KOEHLER, Department of Food Science and Technology, University of Georgia, Athens, GA 30602 and W. B. West. Colorants are often added to fruit flavored yoghurt to enhance or replace the natural color of the fruit. Pigments produced by the mold, Monascus purpureus, offer a possible alternative to certified food dyes or natural pigments now used. The objective of this study was to ascertain the performance of Monascus pigments as coloring agents for yoghurt compared with more traditional red yoghurt colorants. The colors of commercial strawberry yoghurts colored with either FD&C Red#40, beet powder, carmine, or a carmine/annatto mix or yoghurt prepared with various concentrations of Monascus pigments were measured as L, a, b, with a Minolta CR-300 Colorimeter. Color changes (L, Hue angle, and Chroma) in the Monascus colored yoghurt during processing from milk to yoghurt were determined and compared with changes experienced using more traditional colorants. Increasing the Monascus pigment concentration from 0.125% through 0.375% decreased L values from 69 to 61, increased the Chroma from 10 to 16 and changed the Hue angle from 33 to 21 degrees. Yoghurt manufactured with Monascus as colorants closely matched commercial samples of strawberry yoghurt. Color matches could be obtained with delta-E values (color difference) of less than 1.0 There was also no significant difference in the decline in pH during 21 days and the numbers of Lactobacillus and Streptococcus were the same in the uncolored control and the Monascus colored yoghurt. The mean force (0.230N) at first peak measured on an Instron was nearly identical in the control and Monascus-colored yoghurt indicating that the textures were similar. Results suggest that pigments from Monascus purpureus could be an acceptable substitute for traditional colorants in strawberry yoghurt. While the color does change slightly during various production stages, the change is comparable to that of FD&C Red#40 and is less than the changes found using carmine or beet juice powder.
Session 15C, Dairy Foods
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