45C-5 |
Aroma release from strawberry yogurt during eating |
J. B. MEI1, G. A. Reineccius1, T. L. Peppard2, W. B. Knighton3, and E. P. Grimsrud3. (1) Dept. of Food Science & Nutrition, Univ. of Minnesota, 1334 Eckles Ave., Saint Paul, MN 55108, (2) Regulatory & Scientific Affairs, Robertet Flavors, Inc., 10 Colonial Dr., Piscataway, NJ 08854-6840, (3) Dept. of Chemistry & Biochemistry, Montana State Univ., Bozeman, 108 Gaines Hall, Bozeman, MT 59717 Food aroma must be released from the matrix during eating and transported to the olfactory receptors to be perceived. There is a growing body of literature showing that various factors including food/flavor interactions and the textural properties of the food influence this release process and thereby influence flavor perception. In our study, we were specifically interested in determining how yogurt formulation influences aroma release during eating. Twelve yogurt formulations were prepared; experimental design variables included choice and level of thickener (gelatin, modified food starch, and pectin) and sweetener (sucrose, high fructose corn syrup, and aspartame). Yogurt formulations were designed to be representative of commercial yogurt products. Aroma release was measured by Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS). Subjects consumed 5 g of a strawberry flavored yogurt while aroma compounds in the breath were monitored through a modified inlet to the mass spectrometer. The strawberry flavor contained ethyl butyrate, ethyl isovalerate, cis-3-hexenol, 2-methylbutyric acid, g-decalactone, and ethyl methyl phenyl glycidate (though we were unable to monitor the latter two volatiles). Ethyl butyrate was released from the yogurt at the highest concentration while cis-3-hexenol was present at the lowest level. Consistent with the literature, the aroma release profiles showed that the greatest concentration of volatiles was expired in the first breath after swallowing. Results showed that aroma release was suppressed by (bulk) sweeteners, with the greatest effect being seen in yogurt containing 55 DE high fructose corn syrup. In contrast, the addition of thickening agents had no significant effect on the aroma release profiles of the compounds under study. Our data suggest that formulation changes in yogurt have little influence on aroma release (within the boundaries of our study). The only noticeable effect was that suppression of aroma by bulk vs. high intensity sweeteners may require flavors to be incorporated at higher levels.
Session 45C, Food Chemistry: Flavor and aroma chemistry
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