Ethnic hair: Thermoanalytical and spectroscopic differences

Area of Science:

• Hair science
• Biomaterials science
• Cosmetic science

Background:

• Human hair varies significantly across different ethnicities.
• Understanding these variations is crucial for targeted hair care product development.

Purpose of the Study:

• To characterize and identify differences in hair properties among African, Asiatic, and Caucasian ethnicities.
• To correlate these differences with cuticle lipid composition and water interaction.

Main Methods:

• Thermogravimetric analysis (TGA) for water adsorption/desorption.
• Synchrotron-based Fourier transform infrared (FTIR) microspectroscopy for lipid analysis.
• Differential scanning calorimetry (DSC) for thermal stability.

Main Results:

• African hair showed higher permeability and lower cuticle lipid order.
• Caucasian hair had higher water absorption but slower diffusion.
• Asiatic hair exhibited resistance to hydration changes and very low cuticle lipids.
• Significant differences in cuticle lipid distribution and order were observed across ethnicities.

Conclusions:

• Ethnic hair fibers exhibit distinct water permeability linked to cuticle lipid properties.
• These findings have implications for the cosmetic industry, particularly in hair care formulations.
• The study highlights the importance of ethnic-specific approaches in hair science.