36D-6 |
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L. SAMUEL, H. Dogan, and J. L. Kokini. Dept. of Food Science, Rutgers, The State Univ. of New Jersey, Center for Advanced Food Technology, 65 Dudley Rd., New Brunswick, NJ 08901-8520 Textural characterization of foods is a critical aspect of new product development and quality control in the food industry. Texture analysis procedures are generally empirical in nature. For a specific product, the effect of test parameters on the relevance of the data generated must be clearly understood. Variation in test parameters must be minimized for maximum accuracy of results. Objectives of this study included identification of quantitative measures for textural properties of extruded foods through instrumental analysis, and to develop operator independent decision-making tools for reliable and robust interpretation of the experimental data. A wide range of extruded food products were analyzed with the texture analyzer by uniaxial compression and puncture tests (with conical and cylindrical probes). Test parameters studied were probe speed (1-3 mm/sec) and strain level (70-90%). All measurements were done in 20 replicates. Force-deformation curves were analyzed for fracture force, fracture area, gradient, total work, number of peaks and ratio of linear distances. The deformation behavior of the samples under different probes affected the textural information obtained by the different methods. Force-deformation curves from uniaxial compression gave maximum information about the above parameters. Test speed of 1mm/sec and 80% strain level gave most reproducible results. Equations were introduced into the macro to calculate threshold values for the identification of fracture force, fracture area, gradient and peak number. This made the macro operator independent as compared to thresholds based on arbitrary, user defined numerical values. Gradient calculations are also done automatically within the macro. Macros developed in this study proved to be compatible in a wide range of extruded products with different composition, shape and mechanical properties that disintegrate in a similar manner.
Session 36D, Food Engineering: Rheology
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |