259: Emulsifying and Foaming Properties of Pea (Pisum Sativum L.) Vicilin and Legumin Blends

Introduction

Foods are complex systems with multiple phases separated by interfaces. Proteins are essential for stabilizing these interfaces in emulsions (oil-water) and foams (air-water). This study investigated how the pea vicilin and legumin fractions facilitate the formation and stability of these interfaces.

Methods

Legumin-rich and vicilin-rich fractions were isolated from raw pea flour using the pH-shift method and were combined in different vicilin-legumin ratios (0%–100% vicilin, 100%–0% legumin). The solubility of the vicilin-legumin blends at various pH values was determined. Their foaming and emulsifying properties were assessed at 10, 15, and 20 mg protein concentration and pH values of 3, 5, 7, and 9.

Results

Blends containing higher ratios of legumin were least soluble at pH 5 and blends containing higher ratios of vicilin were least soluble at pH 3. Protein solubility decreased from 58.46% to 0% at pH 3 as legumin content reduced from 100% to 0%. The smallest mean oil droplet size (∼3 – ∼10 μm) was observed at pH 7 and 9 in all emulsions. Oil droplet size decreased (∼30 – ∼10 μm) as legumin content decreased from 100% to 0% at pH 5. All emulsions showed the lowest stability at pH 7. Foaming capacity was highest in blends containing 60% vicilin + 40% legumin at pH 9, 80% vicilin + 20% legumin, and 90% vicilin + 10% legumin at pH 5, and 10% vicilin + 90% legumin at pH 3. All foams demonstrated high stability (>80%).

Results demonstrated that the vicilin-legumin ratio and pH influenced the solubility, emulsifying properties, and foaming capacity of vicilin-legumin blends. The isoelectric point influenced protein solubility in acidic pH. Vicilin-rich blends are better emulsifiers at pH 5, and all foams were relatively stable.

Significance

These findings demonstrate that optimizing pea protein functionality through precise formulation can enhance food quality and drive innovations in the development of functional food products.

Authors: Adewunmi R. Giwa, Rotimi E. Aluko