Phytosterols and γ-Oryzanol as Cholesterol Solid Phase Modifiers during Digestion.

Area of Science:

• Nutritional Science
• Food Chemistry
• Thermodynamics

Background:

• Dietary phytosterols and γ-oryzanol are known to lower cholesterol levels.
• Thermodynamic principles may explain cholesterol-lowering mechanisms during digestion.

Purpose of the Study:

• To elucidate the solid-liquid phase equilibrium diagrams of cholesterol with phytosterols and γ-oryzanol.
• To evaluate the impact of these compounds on cholesterol's physical state and digestibility.

Main Methods:

• Differential scanning calorimetry (DSC) for phase equilibria.
• Powder X-ray diffraction and microscopy for structural analysis.
• Thermodynamic modeling and in vitro digestibility assays.

Main Results:

• Cholesterol and phytosterols formed complete solid solutions.
• Cholesterol and γ-oryzanol formed stable liquid crystalline phases with reduced melting points.
• In vitro digestion supported phase changes influencing cholesterol solubility.

Conclusions:

• Phytosterols and γ-oryzanol induce physical changes in cholesterol.
• These changes, potentially driven by mechanochemical forces during digestion, may reduce cholesterol absorption.