Textural and structural changes in lasagna after cooking

Abstract

The effects of cooking time (9.5, 11, and 15 min) and holding time of lasagna pasta after cooking (4 min to 185 min) on the textural properties (through mechanical testing) and internal structure (via nuclear magnetic resonance imaging) were studied. The peak force, which characterized firmness, decreased with increasing cooking and holding time. Work was strongly influenced by the value of the peak force and followed a similar trend. Corresponding NMR images revealed changes in proton signal intensity as a function of position. The NMR signal intensity increased at the center with increasing cooking and holding times. This change illustrates that water migration to the sample center was simultaneous with the decrease in the peak force. The initial slope, associated with the structure of the sample surface region, decreased with cooking time and increased with holding time. The NMR signal intensity of the surface region decreased with holding time; water migration from this region during this period was simultaneous with an increase in stiffness. NMR imaging is an effective technique to evaluate internal structural changes of pasta during holding. Furthermore, it supplements information provided by conventional mechanical testing, facilitating the interpretation of texture measurements.