Interactions between whey protein and inulin in a model system.

Area of Science:

• Food Science and Technology
• Biopolymer Interactions
• Nutritional Science

Background:

• Inulin is a widely utilized prebiotic ingredient in functional food development.
• Understanding its interaction with other food components, like whey protein, is crucial for optimizing food formulations.

Purpose of the Study:

• To investigate the impact of inulin on the gelation characteristics of whey protein.
• To compare the effects of different preparation methods for whey protein and inulin mixtures.

Main Methods:

• Whey protein and inulin (WP/inulin) and polymerized whey protein and inulin (PWP/inulin) mixtures were prepared at varying protein (4-8%) and inulin (1-5%) concentrations.
• Analysis included turbidity, zeta potential, particle size, rheological properties, and cold-set gel hardness.
• Two preparation methods were used: co-heating and sequential heating/mixing.

Main Results:

• Increased protein concentration led to greater opacity, with no significant difference between preparation methods.
• Inulin addition (1-5%) increased particle size and decreased zeta potential in both mixtures.
• Both mixtures displayed shear-thinning behavior, and inulin increased whey protein's transition temperature.
• Calcium-induced cold-set gels showed increased hardness with higher inulin content.

Conclusions:

• Interactions between whey protein and inulin significantly influence whey protein's gelation properties.
• The method of incorporating inulin (co-heating vs. sequential mixing) did not alter the overall impact on gelation.
• Inulin addition enhances the hardness of whey protein gels, suggesting potential for texture modification in functional foods.