Effects of ingredients on gel properties and salt-soluble proteins of sirimi from silver carp

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Silver carp (Hypophthalmichthys molitrix) are an introduced species in central North America that cause enormous environmental damage and have little economic value. They can be regarded as a potential source of surimi products in order to add commercial value. The objectives of this research are to determine, by response surface methodology (RSM), the simultaneous effects of corn starch, egg white and moisture content in the surimi from silver carp based on hardness, gel strength, shear force, pH, and water activity; as well as the cryoprotective effects of sucrose and sorbitol on salt-soluble proteins (SSP) of the surimi. The mathematical model revealed no significant interactive effect among the first three ingredients nor between sucrose and sorbitol. Corn starch and/or egg white exerted a positive impact on gel properties, while moisture content contributed to a more rapid decreasing rate on gel properties than the increasing rate attributed to corn starch and/or egg white. The highest gel strength was reached when starch (3-5%) and egg white (6-8%) were added together. The highest hardness and shear force values would be attained with maximum addition of starch (6%) and egg white (8%). No differences were found in pH, water activity and gender effect regardless of treatment. Salt-soluble protein (SSP) in all treatments decreased distinctly during the first week of frozen storage. Although the highest SSP content was reached when sucrose (4- 5%) and sorbitol (5-6%) were added together, the addition of 4% sucrose and 4% sorbitol still maintain fairly high levels of SSP content during frozen storage.