Effect of preheat treatment of milk proteins on their interactions with cyanidin-3-O-glucoside.

摘要: Abstract In this study, the binding of cyanidin-3-O-glucoside (C3G) to preheated milk proteins β-lactoglobulin (β-Lg) and β-casein (β-CN) at 55–90 °C under pH 3.6 pH 6.3 was investigated using multi-spectral techniques. Fluorescence quenching spectroscopy data showed C3G quenched proteins' fluorescence strongly. Thermodynamic analysis revealed that bound β-Lg mainly through hydrogen bonding hydrophobic interactions, their affinity increased gradually with increasing preheating temperature pH 6.3, whereas it decreased pH 3.6. Hydrogen van der Waals forces played major roles in interaction β-CN C3G, decreasing both pH values. The combination 85 °C had strongest affinity, a KA 14.10 (±0.33) × 105 M−1 (pH 6.3, 298 K). Preheating did not change C3G. Fourier transform infrared spectra (FT-IR) results altered secondary structures by reducing proportion α-helix β-sheet random coil turn structures. structural changes upon were more pronounced than native β-Lg, while there little difference between binding. These will be helpful better understanding relevance protein–C3G interactions stability promoting its application food industry as natural pigment.