341: Improving Protein Solubility of Oat Protein Using pH-Driven and Heat Treatments

Introduction

The poor solubility of oat protein at neutral pH limits its use in oat beverages, highlighting the need for effective solutions.

Methods

This study addresses this challenge by combining alkaline (pH 12) and heat (100°C) treatments, followed by acidification, to enhance and retain oat protein solubility at neutral pH.

Results

Results show that solubilizing oat protein at pH 12 achieves a maximum solubility of 78.28% ± 2.34%. After heating at pH 12, this solubility is retained at pH 7, particularly with citric acid acidification. Particle size analysis reveals that heating reduces oat protein particle size, which further decreases upon acidification at pH 7. Zeta potential (ζ) data indicate the most negative charge at pH 12, with retention of negative charges upon heating, consistent with solubility trends. Microstructure analysis confirms that larger aggregates form at pH 7 without heating, while heating at pH 12 prevents aggregation. Electrophoresis and DSC data show that heating at pH 12 denatures primary oat protein subunits, forming smaller, more soluble aggregates at neutral pH. Stability tests of the pH 7 solution prepared from heated pH 12 oat protein with citric acid reveal superior protein solubility, zeta potential, and particle size stability over 7 days.

Significance

These findings provide valuable insights into the impact of pH and thermal treatments on oat protein, offering practical applications for the food industry to develop oat-based beverages with improved protein functionality.

Authors: Anthony Suryamiharja, Hualu Zhou