Influence of Water Activity and Maillard Reaction on the Polymerization of Myosin Heavy Chain in Freeze-dried Squid Meat

Abstract

Brown discoloration of freeze-dried short-finned squid meat imparted by the Maillard reaction during storage at 25°C was examined as a function of water activity (Aw). The reaction took place fairly fast in intermediate Aw's between 0.4 and 0.7. Similarly, the losses of reducing sugars, glucose, free amino groups, and available lysine during storage were maximum at intermediate Aw's. On the other hand, myosin heavy chain (MHC) content in freeze-dried squid meat decreased as the polymerized subunits of MHC increased during storage. From the developing trends of the Maillard reaction including the increase of discoloration and the decreases of reducing sugars and free amino groups in freeze-dried squid meat, it is suggested that the polymerization of MHC during storage is mostly attributed to the Maillard browning reaction. This was confirmed by experiments using squid meat which had been thoroughly washed with water. © 1994, The Japanese Society of Fisheries Science. All rights reserved.