Enhancing lactoferrin stability in ethanol aqueous systems through oligosaccharide modulation: Mechanisms and functional implications.

To improve protein stability in ethanol aqueous systems, this study investigated the effects of three oligosaccharides-oligofructose (FOS), oligogalactose (GOS), and oligoxylose (XOS)-on the conformational and thermal stability of lactoferrin (LF). Results demonstrated that these oligosaccharides significantly increased LF's thermal denaturation temperature (Tm) and elevated the energy barrier for conformational changes in ethanol aqueous systems, thereby enhancing thermostability. Specifically, FOS, GOS, and XOS raised the Tm of LF from 69.1 ± 0.4 °C to 79.8 ± 1.3 °C, 73.7 ± 0.6 °C, and 76.8 ± 0.6 °C, respectively. Furthermore, the oligosaccharides improved LF's physical stability by suppressing aggregation and precipitation. Molecular docking simulations revealed hydrogen bonding as the primary interaction mechanism between oligosaccharides and LF, with all three exhibiting strong binding affinities. This work provides a strategy for enhancing protein stability in functional alcoholic beverages, highlighting potential applications in food science and technology.