Functionalizing soy protein nano-aggregates with pH-shifting and mano-thermo-sonication

Area of Science:

• Food Science and Technology
• Biomaterials Engineering
• Nanotechnology

Background:

• Plant protein-based nano-delivery systems are gaining traction in food and pharmaceuticals.
• Improving native plant protein functional properties is crucial for these applications.

Purpose of the Study:

• To develop a novel method for producing soy protein nano-aggregates with enhanced functional properties.
• To optimize the mano-thermo-sonication (MTS) process for soy protein isolate (SPI) treatment.
• To evaluate the characteristics and stability of SPI nano-aggregates and their derived nanoemulsions.

Main Methods:

• Soy protein isolate (SPI) was treated using pH-shifting (pH 12) combined with mano-thermo-sonication (MTS) and high-pressure homogenization (HPH).
• Response Surface Methodology optimized MTS conditions (50°C, 200kPa, 60s).
• Transmission electron microscopy analyzed aggregate size; oil-in-water nanoemulsions were prepared with canola oil.

Main Results:

• The combination of pH-shifting and MTS produced spherical SPI nano-aggregates with the smallest size (27.1±1nm).
• SPI nanoemulsions exhibited good stability over 21 days at 4°C.
• pH 12-MTS treated samples showed superior protein solubility, reduced turbidity, improved sulfhydryl/disulfide bonds, higher surface hydrophobicity, and enhanced antioxidant, rheological, and emulsifying properties.

Conclusions:

• The combined pH-shifting and MTS method effectively produces nano-sized soy protein aggregates with significantly improved functional properties.
• These enhanced soy protein nano-aggregates are suitable for creating stable nanoemulsions for potential food and pharmaceutical applications.
• The optimized process offers a promising approach for advancing plant protein-based nano-delivery systems.