External Lipid Function in Ethnic Hairs

The study aimed to characterize the external lipids of different ethnic hairs and their impact on hair properties. It found that African hair had the highest total lipid content, while Caucasian hair had higher melting points and phase transition temperatures, indicating higher hydration and lower diffusion coefficients. Lipid extraction led to decreased moisture and increased water desorption in all hair types. Infrared spectroscopy showed that Caucasian and African hairs had the most lipids with a lamellar/orthorhombic order. The extraction process affected both cuticular and cortex lipids, resulting in less water content and higher desorption, with Caucasian hair showing increased lipid order and improved breaking tenacity.