45C-13 |
Flavor and sensory impact of soy fortification of a dairy-based frozen dessert |
K. FRIEDECK, Dept. Food Science, North Carolina State University, Raleigh, NC 27695, Y. Karagul-Yuceer, and M. A. Drake, Dept. of Food Science, North Carolina State Univ., Schaub Hall, Box 7624, Raleigh, NC 27695-7624. Since the inception of the 1998 FDA approved health claims linking soy and health, soy protein has been investigated as a potential ingredient in many foods. Products containing soy protein have been characterized as having beany or woody off-flavors, which are unacceptable by many American consumers. Frozen dairy dessert products, in comparison, are appealing to many consumers and may potentially serve as carriers for functional ingredients such as soy protein. Understanding the flavor and sensory impact of soy protein in a dairy-based frozen dessert is key to designing soy fortified dairy products with high market acceptability. The goals of this research are to identify and characterize aroma active compounds contributing to off flavors in soy protein fortified dairy-based frozen desserts, and assess associated sensory impacts. Descriptive sensory analysis was conducted on frozen dairy dessert mixes formulated with 0, 2, and 4% soy protein isolate (SPI). Duplicate samples (150g) containing an internal standard were distilled by high vacuum transfer followed by extraction of the distillate with diethyl ether. Extracts containing volatile compounds were separated into neutral-basic and acidic fractions and analyzed by gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Comparison of retention indices, odor properties, and GC-MS data against reference standards was performed for identification of compounds. SPI fortified dessert mixes displayed beany and grassy flavors that increased in intensity with added SPI. Texture properties were also different; soy fortification increased mouth viscosity and mouthcoating. GC-O analysis revealed higher concentrations of hexanal(green), (Z)-4-heptanal (fishy/oily), 2-acetyl-1-pyrroline (nutty/popcorn), 1-octen-3-one (mushroom), 2-phenylethanol (rosey), and (E,E)-2,4-decadienal (fatty/frier oil) and decreased concentrations of acetic (vinegar/sour), and butanoic acid (cheesy/sour) in the SPI fortified samples compared to controls. This information will aid in design and optimization of an acceptable soy fortified frozen dairy dessert.
Session 45C, Food Chemistry: Flavor and aroma chemistry
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