LAUSR

BACKGOUND Hydrocolloids is the most commonly used additive in the processing of surimi products. However, the effect of hydrocolloids on surimi protein conformation has not been reported and the level of hydrocolloids may be a key factor influencing the quality of surimi. Therefore, this study investigated the effect of curdlan, xanthan gum, k-carrageenan and gelatin at various levels on gel properties and protein conformation of surimi from silver carp. RESULTS Addition of curdlan, k-carrageenan or gelatin at lower level could significantly promote gel strength, textural profiles and water holding capacity (WHC) of the surimi gels. However, gel strength and WHC gradually decreased with the increasing of added xanthan gum. The addition of curdlan or k-carrageenan remarkably increased the whiteness of surimi gel, but the whiteness decreased when the concentration of k-carrageenan reached to 5 g kg-1 . Along with the increase of curdlan, k-carrageenan or gelatin concentration, index of hydrophobic interaction and hydrogen bond first increased and then decreased, while index of ionic bond first decrease and then increased. According to Raman spectroscopy data, small content of curdlan or k-carrageenan promoted the conformational transition of surimi protein from α-helix to β-sheet, leading to the changes in gel properties of surimi gels. SEM photographs showed surimi gels added with 4 g kg-1 curdlan or 2 g kg-1 k-carrageenan had the finer and denser network structure. CONCLUSION Curdlan or k-carrageenan at proper concentration is potential modifier to effectively improve the quality of surimi products. This article is protected by copyright. All rights reserved.