Abstract
As the number of Japanese people who have bleached or penned hair has increased, hair damage caused by chemical treatments has become the subject of much discussion. In response, morphological techniques to analyze hair damage have focused on the hair surface, such as the cuticle condition and hair color. However, little is known about the contribution of inner structure of human hair on this issue. The authors have developed a convenient method of extracting proteins from human hair in the absence of detergent, which is called the ‘Shindai method’. Using this method, we examined lightness/saturation, sensory evaluation, and biochemical analysis of human hair samples after several bleach treatments. We found a significant correlation between sensory evaluation of damaged hair and the extraction velocity of protein from it.
