Sodium ion interaction with psyllium husk (Plantago sp.)

Area of Science:

• Food Science
• Nutritional Science
• Biochemistry

Background:

• High sodium intake is a significant public health concern linked to cardiovascular diseases.
• Dietary interventions are sought to reduce sodium absorption and bioavailability.

Purpose of the Study:

• To investigate the in vitro interaction between sodium and psyllium.
• To evaluate psyllium husk's potential as a sodium-binding agent for reducing bioavailability.

Main Methods:

• Batch extraction system to determine sodium retention by psyllium mucilage gel.
• Fourier-transform infrared (FTIR) spectroscopy and Sodium Nuclear Magnetic Resonance (Na NMR) analyses.
• Gastrointestinal tract (GIT) pH simulated model to assess sodium binding under physiological conditions.

Main Results:

• Psyllium mucilage gel retained at least 50% of sodium across various concentrations (5-300 mg/g) and pH (2-10).
• FTIR and Na NMR analyses revealed complex, non-specific, multi-site interactions between sodium and psyllium.
• In a simulated GIT model, consistent high sodium retention (∼50%) was observed.
• Less than 20% of bound sodium was lost under simulated intestinal pH conditions after repeated washings.

Conclusions:

• Psyllium husk demonstrates significant sodium-binding capacity.
• The binding is complex and occurs across a wide pH range, including physiological conditions.
• Psyllium husk shows promise as a functional ingredient for reducing dietary sodium bioavailability.