Moisture distribution and texture of various types of cooked spaghetti

Cooked spaghetti of various types (fresh, dried, frozen, luncheon, and long-life spaghetti) was examined for moisture distribution by magnetic resonance imaging (MRI). Moisture content was calculated from spin-spin relaxation time (T-2) of water proton, based on the correlation between T-2 and moisture content of pulverized durum semolina standard gel samples. Boiled samples of dried and frozen spaghetti had a distinct low moisture region at the center, which was not clearly observed in the other types of boiled spaghetti samples. In particular, the moisture content of boiled long-life spaghetti was almost homogeneous. Texture of cooked spaghetti samples was evaluated using the force-distance curve of a mechanical property test. For dried and frozen spaghetti, higher force was observed at the region corresponding to the low moisture core compared with the other types. The luncheon spaghetti and long-life spaghetti showed a lower breaking force and a larger dip after the peak force representing soft and brittle texture caused by moisture homogeneity. These results indicated that MRI could be used for the quality evaluation of cooked spaghetti through imaging of the moisture distribution, which reflects the mechanical property.