61B-26 |
Temporal release of flavor compounds during the mastication of ice cream of varied fat levels |
S. J. CHUNG, L. N. Fernando, H. Heymann, and I. U. Gruen. Department of Food Science, University of Missouri - Columbia, 256 Eckles Hall - Stringer Wing, Columbia, MO 65211 Fat acts as a solvent for many odor-active volatiles. Due to this physico-chemical characteristic, fat controls the intensity and the rate of release of volatiles. Therefore, temporal and overall flavor profiles change when fat is substituted with carbohydrate or protein-based fat replacers in foods. The objective of this study was to understand the effect of fat on the release behavior of selected odor-active compounds during the consumption of ice cream using sensory and chemical analyses. The temporal volatile profiles of model ice cream systems containing various fat levels and known amounts of spiked volatiles (hexanal, vanillin, benzaldehyde) were determined by two chemical analyses, namely a modified purge and trap (PT) and a direct in-nose breath analysis (DINBA). For DINBA, the breath of 8 panelists was collected into an adsorbent while eating ice creams. For PT, the extraction was performed in a device with mechanical input at 37ºC. The volatiles were analyzed by GC-MS. Temporal changes of vanilla, cherry, and stale flavor were measured by time-intensity analysis (T-I). Hexanal and benzaldehyde, which are responsible for stale and cherry flavor respectively, were released faster and at higher intensity as fat content decreased, using the PT method. These observations agreed with the results from T-I analysis. Due to its hydrophilicity, we were not able to monitor the release of vanillin using the instrumental methods. However, vanilla flavor was released faster, at higher intensity and persisted longer as the fat level increased when measured by T-I. The results obtained from the breath analysis were highly varied between and within subjects. The volatile profile of ice cream using breath analysis was obscured due to the background breath volatiles. Modified PT analysis was shown to be a good instrumental method to observe the release behavior of highly volatile compounds and correlated well with temporal flavor perception.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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