Effects of microwave reheating on surimi gel texture

Microwave re-heating of a surimi gel may change its mechanical properties by introducing defects into the protein gel matrix. These defects result from the localized hot spots that are generated due to the non-uniform nature of microwave heating, especially at high output power. When the temperature at these hot spots is above the boiling point, the resulting high water vapor pressure may overcome the gel cohesion forces and create structural defects. This phenomenon will not take place in the absence of loci having a temperature above boiling point. The latter is the case when re-heating is done by hot water, steam, low power microwave, and even by high-power microwave, as long as the temperature is well below the boiling point. The structural changes due to these defects seem to weaken the gel structure, which is opposite to the effect caused by moisture lost. (C) 1998 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.