29C-21 |
Rheological properties of shelf-stable pudding |
M. C. ANDERSON and R. P. Singh. Dept. of Biological & Agricultural Engineering, Univ. of California, Davis, 1 Shields Ave., 2030 Bainer Hall, Davis, CA 95616-5294 Convenience products have flooded the marketplace to aid the hurried lifestyles of current consumers. One such product is shelf-stable, ready-to-eat pudding. Though convenience and product safety are the main selling points, expectations of high product quality still reside in flavor and texture. One way to capture texture is to explore a product’s rheological properties. Limited information on pudding rheology was found in published literature. This study was conducted to provide rheological characteristics of shelf-stable, ready-to-eat pudding. In addition, the relationship of these characteristics with temperature was investigated. Pudding samples were bought from a local grocery store. Using a Thermo Haake Rheometer (RS 1) with concentric cylinder geometry, puddings with different flavors, fat contents, and temperatures were examined under shear rate ramp conditions. When the sample came to rest after 5 minutes, the rheometer was programmed to ramp from 0 s-1 to 50 s-1 in 30 seconds. Flavors tested were vanilla, chocolate, and low-fat chocolate. Sample temperature ranged from 4°C to 40°C. At higher temperatures, silicon oil was used to coat the top surface of the sample to prevent moisture loss. Each flavor and temperature combination was run in triplicate. Pudding samples exhibited shear thinning properties. When apparent viscosity (Pa∙s) was plotted as a function of shear rate (s-1), the consistency coefficient, K (Pa∙s^n), and flow behavior index, n, were determined for each sample. At room temperature (25°C), average K and n values were 49.7 Pa∙s^n and 0.27 for vanilla pudding, 111.2 Pa∙s^n and 0.18 for chocolate pudding, and 55.5 Pa∙s^n and 0.30 for low-fat chocolate. These rheological parameters of commercial puddings at different temperatures provide important information on quality at various serving temperatures. Such an examination can lead to proper selection of ingredients and processing conditions that can improve product quality and consistency.
Session 29C, Food Engineering: Rheology and texture
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