Main protein components in frozen surimi contributed to heat-induced gel formation

Directly heated gel (90 degrees C) and two- step heated gel (25 and 90 degrees C) were prepared from surimi made from arabesque greenling and walleye pollack, either with or without added 3% albumen powder (AP). The resulting heat-induced gels were solubilized in solvents containing 0.6 M NaCl, 1.5-8.0 M urea, 2% mercaptoethanol, and 2% sodium dodecyl sulfate (SDS) in various combinations, and the compositions of the dissolved proteins were analyzed by SDS-polyacrylamide slab gel electrophoresis. For greenling, the main proteins contributing to the heat-induced gel structure were myosin heavy chain (MHC) and actin (AC) in the case of directly heated gel, and were AC, MHC, and unidentified component X1 (140.2 kDa) in the two- step heated gel. In either gel type, the formation of the gel structure was suggested to involve strong disulfide bonds and hydrophobic interactions. On the other hand, for pollack, the gel structure formation was suggested to involve MHC and AC in the directly heated gel and MHC polymer and AC in two- step heated gel, through the concerted action of strong hydrophobic interactions, disulfide bonds, and isopeptide bonds. However, the addition of 3% AP did not result in any notable changes, regardless of the fish species. (c) All Rights Reserved.