MORPHOLOGY OF STARCH IN SURIMI GELS

The purpose of this work was to study the changes undergone by starch during heat-induced surimi gel preparation either with or without adde d egg white, and their effects on the structure of gels using light an d scanning electron microscopy. Gels were made from SA-grade Alaska po llack (Theragra chalcogramma) surimi with: (1) salt (3%, w/w); (2) sal t and waxy corn starch (3% and 5%, respectively w/w); or (3) salt, wax y corn starch and egg white (3%, 5% and 5%, respectively? w/w). Final moisture was adjusted to 73% or 83%. The gels were prepared by prior s etting (40 degrees C, 30 min, followed by 90 degrees C, 30 min) or coo king (90 degrees C, 30 min). The prepared gel was frozen and stored at -20 degrees C (+/- 1 degrees C) until analysis. Samples were observed by light and scanning electron microscopy. The results show that the starch granules alter according to the processing conditions, with the predominance of crystalline or amorphous morphology depending upon th e availability of heat and water. Large cavities formed in the protein gel matrix during setting can trap water; as a result, water availabi lity is limited for starch to swell and gelatinize even in the high-mo isture gel.