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

Area of Science:

• Food Science and Technology
• Biochemistry
• Protein Chemistry

Background:

• Protein stability is crucial for applications in food and beverages, especially in ethanol-containing systems.
• Lactoferrin (LF) stability can be compromised in ethanol aqueous environments.
• Oligosaccharides are known to interact with proteins and potentially stabilize them.

Purpose of the Study:

• To investigate the impact of oligofructose (FOS), oligogalactose (GOS), and oligoxylose (XOS) on the conformational and thermal stability of lactoferrin (LF).
• To explore the potential of these oligosaccharides as stabilizers for LF in ethanol aqueous systems.

Main Methods:

• Thermal denaturation studies using differential scanning calorimetry (DSC) to determine the denaturation temperature (Tm).
• Assessment of conformational changes and physical stability (aggregation, precipitation) in ethanol-containing solutions.
• Molecular docking simulations to elucidate the interaction mechanisms between oligosaccharides and LF.

Main Results:

• All three oligosaccharides (FOS, GOS, XOS) significantly increased the thermal denaturation temperature (Tm) of LF in ethanol aqueous systems.
• FOS, GOS, and XOS raised LF's Tm from 69.1°C to 79.8°C, 73.7°C, and 76.8°C, respectively.
• Oligosaccharides effectively suppressed LF aggregation and precipitation, enhancing its physical stability, with hydrogen bonding identified as the key interaction mechanism.

Conclusions:

• Oligofructose, oligogalactose, and oligoxylose are effective stabilizers for lactoferrin in ethanol aqueous systems.
• These oligosaccharides enhance both thermal and physical stability of LF by increasing Tm and preventing aggregation.
• The findings offer a viable strategy for improving protein stability in functional alcoholic beverages and related food applications.