Abstract:To investigate the effect of frying temperature on the collagen structure of Shaobai pork skin, spectral analyses (UV, intrinsic fluorescence, and Fourier transform infrared spectroscopy), surface hydrophobicity, active sulfhydryl content, and microscopic structure measurements were conducted on Shaobai pork skin collagen under five different frying temperatures (120, 140, 160, 180, 200 ℃). The results showed that the UV absorption intensity exhibited a “decrease-increase-decrease” trend with the increase of frying temperature. The intrinsic fluorescence intensity was higher than that of the control group, but overall decreased with increasing temperature; Fourier transform infrared spectra indicated that different frying temperatures promoted the transformation of α-helix and β-turn into β-sheet and random coil, with the lowest α-helix content (9.49%) and the highest degree of disorder (44.88%) observed at 180 ℃. Surface hydrophobicity reached a peak of 36.83 μg at 180 °C and decreased to 33.08 μg at 200 °C. The content of active sulfhydryl continuously increased with rising frying temperature,with an increment ranging from 1.35 nmol·mL?1 to 7.72 nmol·mL?1. Scanning electron microscopy revealed that as the frying temperature increased, collagen molecules gradually degraded and fragmented, transitioning from a layered structure to spherical aggregates. In conclusion, frying temperature significantly regulates the collagen structure of Shaobai pork skin. High-temperature frying exacerbates collagen structural damage and affects the quality of Shaobai pork. From the perspective of protein structural changes, it is recommended to control the frying temperature between 160 ℃ and 180 ℃. This study can provide some theoretical guidance for the industrial production of Shaobai pork.
