Probing soy protein-aldehyde binding by inverse liquid chromatography on protein-packed columns

Area of Science:

• Food Science
• Analytical Chemistry
• Biochemistry

Background:

• Protein-flavor interactions are key to plant-based food sensory quality.
• Limited rapid methods exist for studying these interactions dynamically.
• Understanding these interactions is vital for improving plant-based food products.

Purpose of the Study:

• To develop and validate a rapid inverse liquid chromatography (ILC) method.
• To investigate the binding behavior of aldehydes with soy protein isolate (SPI).
• To elucidate the thermodynamic parameters and adsorption mechanisms involved.

Main Methods:

• Preparation of a soy protein isolate (SPI)-based stationary phase on silica.
• Utilizing inverse liquid chromatography (ILC) to analyze aldehyde binding.
• Quantifying flavor retention, binding percentages, and thermodynamic parameters (ΔG).

Main Results:

• Binding increased with aldehyde chain length, reaching up to 96% for longer chains.
• Spontaneous, chain-length-dependent binding was observed (ΔG from -17.0 to -26.0 kJ·mol⁻¹).
• Binding shifted from enthalpy-driven (short chains) to entropy-driven (long chains), indicating hydrophobic interactions.

Conclusions:

• ILC is a rapid and effective method for studying protein-flavor adsorption.
• Hydrophobic effects significantly influence aldehyde binding to SPI.
• This method offers a complementary approach for analyzing plant-based protein systems.