Evaluating the efficacy of citrus fruit peel extract in preserving the quality of silver carp (Hypophthalmichthys molitrix) surimi during frozen storage

This research investigated the effects of mosambi peel extract (MPE) on the stability of protein and textural characteristics of silver carp surimi during frozen storage at −20 °C. The findings revealed that surimi fortified with 0.75 % MPE displayed upgraded protein solubility (PS), water holding capacity (WHC), Ca 2+ -ATPase activity, and sulfhydryl (SH) content. It also exhibited reduced levels of total carbonyls and surface hydrophobicity, along with higher overall acceptability compared to surimi treated with synthetic cryoprotectants (control) throughout storage. Additionally, MPE slowed down the increase in total volatile basic nitrogen (TVBN) and protein degradation index (PI), as evidenced by SDS-PAGE showing higher intensities of myosin heavy chain (MHC) and actin over the storage period. Moreover, the incorporation of MPE effectively mitigated lipid oxidation as peroxide value (PV), and thiobarbituric acid (TBA) were lesser than control. Fourier-transform infrared spectroscopy (FTIR) peaks specified that the relative content of α-helix and β-sheet structures remained more stable in the MPE-treated group compared to the control, along with the improved gel and textural properties of surimi. Hence, this study suggests that 0.75 % MPE could serve as a natural alternative to synthetic cryoprotectants, ensuring the oxidative stability of silver carp surimi during frozen storage while enriching it with beneficial bioactive compounds. • MPE (0.75 %) enhanced protein solubility, WHC, Ca 2+ -ATPase activity, and SH content. • Surimi with MPE had reduced carbonyls and surface hydrophobicity, and higher acceptability. • MPE slowed TVBN, and PI increases; myosin heavy chain and actin were preserved. • Lipid oxidation was reduced; PV and TBA levels were lower in MPE-treated surimi. • FTIR showed stable α-helix and β-sheet structures; improved gel and texture properties.