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M. J. MCCARTHY¹, K. L. McCarthy, and J. J. Gonzalez. (1) Food Science and Technology, University of California, Davis, One Shields Ave., Davis, CA 95616-8598

The migration of components within foods results in changes in food properties. This study focuses on measurement and modeling of moisture migration post-cooking in lasagna pasta. The effects of cooking time (9.5, 11, and 15 min) and holding time of lasagna pasta after cooking (12 - 120 min) on the internal structure via magnetic resonance imaging (MRI) were studied. The imaging experiments were performed on a 7T Bruker Biospec imaging spectrometer operating at 300 MHz. A spin-echo based imaging sequence was used, in which the timing parameters, the echo time (TE) and the repetition time (TR), were set to 18 and 500 ms, respectively. The imaging resolution was 59 µm X 59 µm with a 2 mm slice thickness. Each of the images acquired consisted of three 7.5 mm X 64 mm slabs of cooked pasta. Using a water standard, the signal intensity was normalized to allow direct comparison of moisture migration as a function of different cooking and holding times. MR images revealed changes in proton signal intensity as a function of spatial position and cooking and holding times. The surface region contained higher moisture content because of direct exposure to boiling water during cooking. Proton signal intensity decreased as a function of the distance from the surface into the center due to the existence of moisture gradients along the thickness of each pasta slab. The center of the pasta had the lowest signal intensity due to limited hydration. Self-diffusion coefficients were measured in the range of 6 - 20 cm²/s, as a function of moisture content. MRI techniques provide information that enables the selection of the optimal cooking and hold time conditions that best maintain structural quality of freshly cooked pasta in food service applications.