Internal Structure Changes in Bleached Black Human Hair Resulting from Chemical Treatments: A Raman Spectroscopic Investigation

August 2014 in “ Journal of molecular structure ”

Akio Kuzuhara

Raman spectroscopy bleached hair permanent waving l-cysteine disulfide bonds keratin cysteic acid oxidation reduction hydrolyzed eggwhite protein keratin associated protein CYS HEWP KAP

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Studysummary In this study, the authors concluded that a hydrolyzed eggwhite protein treatment promoted the reconnection of disulfide bonds in excessively bleached hair, after reduction and oxidation processes in permanent waving.

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In a study from November 2014, researchers used Raman spectroscopy to analyze the internal structure of excessively bleached black human hair fibers that had undergone a permanent waving process. They discovered that the treatment with l-cysteine (CYS) primarily reacted with the gauche-gauche-gauche (GGG) conformation of disulfide bonds in the hair keratin, leading to a significant decrease in both GGG and cysteic acid content throughout the cortex after oxidation following reduction. Additionally, the oxidation process after reduction and hydrolyzed eggwhite protein (HEWP) treatment increased GGG content and decreased trans-gauche-trans (TGT) content. The study concluded that keratin associated protein (KAP), which is rich in disulfide bonds, was lost from the cortex due to the breaking of these bonds, reducing the reconnection of disulfide bonds after chemical treatments. Furthermore, HEWP treatment was found to aid in the reconstruction of KAP, enhancing the reconnection of disulfide bonds during the oxidation process.

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Research cited in this study

4 / 4 results

research Analysis of Heterogeneous Reaction Between Reducing Agents and Keratin Fibers Using Raman Spectroscopy and Microspectrophotometry

20 citations , December 2012 in “Journal of molecular structure”

This study found that at pH 9.0, CYS penetrated less and caused less damage to virgin human hair than TG because it barely reached the cortex region.

research Analysis of Structural Changes in Permanent Waved Human Hair Using Raman Spectroscopy

45 citations , December 2006 in “Biopolymers”

This study found that permanent waving treatment induces structural changes in the cortex proteins of white human hair, significantly reducing its tensile strength without altering the S-S band intensity.

research Conformational Differences in Protein Disulfide Linkages Between Normal Hair and Hair From Subjects With Trichothiodystrophy: A Quantitative Analysis by Raman Microspectroscopy

53 citations , March 2006 in “Biopolymers”

This study suggests that increased amounts of less stable disulfide conformers in hair shafts may be linked to the brittleness observed in trichothiodystrophy.

research Analysis of Structural Change in Keratin Fibers Resulting from Chemical Treatments Using Raman Spectroscopy

52 citations , February 2005 in “Biopolymers”

In this study, chemical treatments during permanent hair straightening were found to randomize proteins in the cortex, aiding in the reconnection of disulfide bonds during oxidation.