Interaction between cereal β-glucan and proteins in solution and at interfaces

Area of Science:

• Food science and nutrition
• Biochemistry
• Dietary fiber research

Background:

• Cereal beta-glucan (β-glucan) is recognized for health benefits, including cholesterol reduction and decreased heart disease risk.
• The physiological effects of β-glucan are linked to its dissolution and aggregation during digestion.
• Proteins may influence β-glucan's aggregation behavior and the formation of viscous slurries.

Purpose of the Study:

• To investigate the interaction and aggregation behavior of a β-glucan isolate (OBC90) with gliadin and whey protein.
• To examine the influence of pH, protein/β-glucan ratio, and interfaces on these interactions.
• To elucidate the role of electrostatic interactions in β-glucan-protein aggregation.

Main Methods:

• Solution-based studies of β-glucan and protein mixtures.
• Investigation of aggregation kinetics under varying pH and protein/β-glucan ratios.
• Analysis of interactions at interfaces.

Main Results:

• Aggregates formed at low pH, with composition dependent on the protein type.
• Phosphate presence in β-glucan contributed to a net negative charge at pH ≤ 4.
• Evidence suggests electrostatic interactions are key to β-glucan and protein aggregation.

Conclusions:

• The interaction between cereal β-glucan and proteins is pH-dependent, leading to aggregate formation.
• Protein type significantly impacts the characteristics of the formed aggregates.
• Electrostatic interactions play a critical role in mediating the aggregation of β-glucan with proteins during digestion.