Effects of Agar-Gelatin Blends on the Quality of Large Yellow Croaker Aspic

In order to address the challenges of low yield, inadequate gel strength, and high susceptibility to melting at ambient temperature in the industrial production of large yellow croaker aspic, this study evaluated the effect of agar-gelatin blends on its appearance, overall sensory score, hardness, brittleness, and springiness. It determined the optimal blend ratio and total concentration, assessed the effect of the optimal blend on the product’s yield, melt resistance, and overall quality, and elucidated the underlying mechanisms using Fourier transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (LF-NMR), and scanning electron microscopy (SEM). The optimal formulation consisted of agar and gelatin at a mass ratio of 1:1 with a total concentration of 1.0 g/100 mL. Under these conditions, the yield of fish aspic significantly increased compared with that of traditional yellow croaker aspic (44.30% vs. 24.62%; P < 0.01). The product retained its integral three-dimensional shape after 4 hours at 30 ℃; its mass loss rate decreased significantly, and its springiness (9.59 mm) and gel strength (510.80 g·mm) increased relative to traditional fish aspic. Meanwhile, no significant differences were found between them in moisture, ash, or fat contents (P > 0.05), nor were any visually perceptible changes in color observed. Fourier transform infrared spectroscopy analysis indicated the presence of hydrogen bonding, weak electrostatic interactions, or hydrophobic interactions between the agar-gelatin blend and the aspic matrix. Low-field nuclear magnetic resonance analysis demonstrated the agar-gelatin blend enhanced the water-binding capacity of the aspic, and scanning electron microscope revealed that the agar-gelatin blend reduced the pore size. These findings offer a scientific foundation and technical support for the industrial application and standardized production of large yellow croaker aspic.