Effect of Quercetin from Onion Extracts on the Gel-forming Ability of Alaska Pollock (Theragra chalcogramma) and Pangasius (Pangasius hypophthalmus) Frozen Surimi A Comparative Study

Abstract

This study evaluated the effect of quercetin from onion extracts (OE) on the gel-forming ability of Alaska pollock and pangasius frozen surimi. In this study, 0%-0.10% OE of the surimi was used to prepare 20- and 120-min heated gels at temperatures ranging from 30°C to 90°C at 10°C intervals. Alaska pollock surimi gels did not show any significant improvement after adding OE for breaking force. Conversely, the addition of the OE increased the breaking force of pangasius surimi gels (p < 0.05) heated at 50°C-90°C for 20 min and 40°C-90°C for 120-min compared with those without gels heated for the same time. The whiteness of gels from two species of surimi decreased with increasing concentration of OE. Meanwhile, when 0.075% OE was added, the α-helix content decreased, the ß-sheet increased in pangasius gel, whereas the hydrophobic interaction noticeably increased in pangasius gels added with OE. Therefore, OE enhanced the formation of ß-sheet structures and hydrophobic interactions, which contributed to the better gel strength in pangasius surimi gel, signifying that OE can be an alternative to improve the strength of gels from low-grade frozen surimi.