Effects of hsian-tsao polysaccharide on myosin gel structure and its binding capacity to flavor compounds

Abstract

Hsian-tsao polysaccharide (HTP) with preferable biological activities was explored to improve the gel qualities of surimi. This study investigated the effects of HTP (0–1.0 mg/mL) on structural changes, in vitro digestibility, and fishy odor binding capacity of heat-induced myosin gels (30 mg/mL). HTP promoted the unfolding of myosin structure with transitions from α- helixes to β-sheets, accompanied by the enhancement of hydrophobic bonds, hydrogen bonds, and non-disulfide covalent bonds dominated within gel networks. Moreover, HTP facilitated the formation of compact gel structures of myosin with superior elastic properties (G′ > G′′) and apparent viscosity, but without affecting the final in vitro digestibility. Moreover, the microstructure of gels markedly affected the adsorption rate of flavor compounds, with a lower adsorption rate obtained for myosin-HTP gels with compact gel networks embedded with evenly small cavities. Additionally, HTP affected the flavor-binding capacities of myosin gels by increasing hexanal and heptanal, but reducing nonanal and 1-octen-3-ol, in relation to the combined effects of myosin structural changes and newly formed gel networks. This work provides a new prospect for application of HTP to regulate the adsorption rate and binding capacity of myosin gels to fishy odors, critical for improvement of gel properties in surimi products.