Gelling properties of white shrimp (Penaeus vannamei) meat as influenced by setting condition and microbial transglutaminase

The properties of white shrimp (Penaeus vannamei) gel added with different levels of microbial transglutaminase (MTGase) and subjected to setting at 25 degrees C for 2 h or 40 degrees C for 30 min, prior to heating at 90 degrees C for 20 min were studied. Breaking force of gels with and without setting increased with increasing MTGase amount added (P<0.05). However, no changes in deformation in all samples were noticeable (P>0.05). Directly heated gels showed the lower breaking force than those with prior setting at all MTGase levels added (P<0.05). Generally, gels prepared by setting at 25 degrees C exhibited the greater breaking force than those set at 40 degrees C, possibly associated with the appropriate protein structure for cross-linking at 25 degrees C and greater degradation at 40 degrees C as evidenced by a greater trichloroacetic acid soluble peptide content (P<0.05). Sodium dodecyl sulfate polyacrylamide gel electrophoretic study revealed that myosin heavy chain (MHC) underwent polymerization to a higher extent in the presence of MTGase, but the strengthening effect on gel was dependent on setting temperature. Regardless of setting condition, microstructure of gel added with MTGase was finer with a smaller void, compared with those of Eel without MTGase. Therefore, setting temperature played an essential role in gel property of white shrimp meat added with MTGase. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.