Study on regulation and effect mechanism of fish collagen peptide on retrogradation of corn starch gel

This study aimed to investigate the inhibition effect and mechanism of fish collagen peptide (FCP) on the gel retrogradation properties of corn starch (CS). The results showed that FCP reduced the gel hardness of CS and slowed down the hardness growth rate within 14 d (26.96%). Pasting and thermal analysis indicated that FCP delayed CS pasting, decreased setback value, and raised the onset, peak, and end temperature of CS gels, with a positive correlation to its concentration. After 14 d of storage, the degree of retrogradation (R) of the CS+100% FCP gel was reduced by 43.35% compared to CS gel alone. Inverted fluorescence microscopy (IFM) analysis demonstrated that FCP was embedded within starch, disrupting the formation of ordered structures during starch retrogradation. Low-field nuclear magnetic resonance (LF-NMR) analysis indicated that FCP primarily influenced changes in weakly bound water and free water, consequently constraining water utilization by CS during gelatinization and retrogradation processes. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses revealed that FCP weakened the intermolecular hydrogen bonding of starch molecules. Consequently, FCP held considerable promise as a starch retrogradation regulator, which could extend the shelf life and enhance the quality of starchy food.