Enhancing pea protein functionality via media milling and pH-shifting

Area of Science:

• Food Science and Technology
• Protein Chemistry
• Materials Science

Background:

• Pea protein isolate (PPI) is a valuable plant-based protein source with broad food applications.
• Poor solubility of dried PPI limits its functional properties and processing versatility.
• Optimizing PPI structure and functionality is crucial for expanding its use in the food industry.

Purpose of the Study:

• To investigate the impact of stirred media milling (SMM) combined with various pH-shifting treatments on pea protein isolate (PPI) structure and functionality.
• To determine the optimal pH conditions for enhancing PPI solubility and functional properties through SMM.
• To explore the relationship between structural modifications and functional performance of treated PPI.

Main Methods:

• Pea protein isolate (PPI) subjected to stirred media milling (SMM) at different pH values (2, 4, 7, 8, 10).
• Analysis of protein solubility, particle size, surface charge, surface morphology (SEM), surface hydrophobicity, and thermal stability.
• Evaluation of emulsifying properties and emulsion stability of the treated PPI.

Main Results:

• Alkaline SMM (pH 10) significantly increased PPI solubility from 24.80% to 74.85%, outperforming acidic SMM (pH 2, 43.90%).
• Alkaline treatment resulted in porous surface morphology, increased surface hydrophobicity, and altered vicilin subunit composition.
• Proteins treated at extreme pH (2 and 10) showed smaller particle sizes, higher surface charge, and improved thermal stability.
• SMM at pH 2 and 7 yielded stable emulsions, while pH 4 and 8 resulted in poor emulsifying performance despite good ionic stability.

Conclusions:

• The combination of SMM and pH-shifting is an effective strategy for enhancing PPI solubility and functionality.
• Alkaline pH-shifting (pH 10) is particularly effective in improving PPI solubility and modifying its structure.
• This approach provides a versatile method for tailoring plant-based proteins for diverse food applications.