Abstract: The objective of this study was to evaluate the effect of potato starch and transglutaminase (TG) on the functional properties (gelling and emulsifying properties) of myofibrillar protein from common carp muscle. potato starch was added at 0%, 1%, 2%, 3%, and 4%, and transglutaminase (TG) at 0%, 0.10%, 0.30%, 0.50%, and 0.70%. Heat-induced gels were formed at different temperatures (60 and 70 ℃). Changes in protein profiles were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as well. Results indicated that gel hardness and springiness significantly increased with potato starch and transglutaminase content at the same temperature (P < 0.05). No significant difference in gel whiteness was observed at different temperatures (P > 0.05). Water holding capacity of gels was increased at higher temperature. The additives markedly affected the emulsion stability but not the emulsifying activity of myofibrillar protein, which initially increased and then decreased with increasing contents of the additives. When potato starch and transglutaminase were added at 2% and 0.5%, respectively, emulsifying stability index (ESI) reached a maximum value of 94.5%. SDS-PAGE showed that the addition of potato starch and TG could weaken the intensity of myosin heavy chain and actin band, thereby significantly affecting protein structure and functional properties.

Key words: transglutaminase, myofibrillar protein, functional properties, potato starch, common carp