The wheat protein gluten is going through a bad PR phase right now. But regardless of how you feel about eating it, the controversial grain ingredient is making new waves in the realm of personal care.
A study led by the School of Food Science and Technology at Jiangnan University, China, gives gluten a chance to win back its lost affection with the finding that it can effectively – and cheaply – repair split ends.
Human hair is chiefly composed of bonded molecules of the fibrous protein called keratin, as well as smaller peptides. The texture of each shaft is determined by the formation of molecular bonds between different keratin fibers, called disulfide bridges. The appearance of smooth, healthy hair arises from uniform disulfide bridges that hold the hair's outer surface closely together.
Heat styling, UV radiation, and certain chemicals – including those in many hair care products – will break these bridges, leading to split ends and brittle texture because the inside of the hair is not sticking to itself properly. Conditioners and restorative treatments attempt to repair the hair’s matrix by filling the gaps with new protein molecules.
Unfortunately, most formulations are largely ineffective because free proteins of the right size and shape for the job are neutrally charged at the pH of most hair products (5 to 6). This means they won’t bond with the hair’s existing keratin fibers, which are negatively charged at that pH.
Enter wheat proteins.
Gluten is a great candidate for hair repair because it's cheap and its composite molecules contain many disulfide bonds. Yet it too is plagued by the pH issue.
The Jiangnan team’s research, published in the Royal Society Open Science journal, overcomes this problem with the discovery that a chemical compound called EDDAC will break down gluten into free peptides that are positively charged [quaternized] and happy to bond with hair at a pH of 5-6.
To test the product’s potential benefit, it was added to a shampoo and washed through human hair strands. The friction required to pull a comb through the hair was then measured. Apparently, it glided quite nicely.
Newly formed disulfide bridges were visually confirmed using a microscope.
“The results showed the shampoo with [quaternized wheat protein] possessed excellent properties for recovering damaged hair, making the surface of hair smooth and compact.”
Though a product won’t be hitting our shelves until more testing is completed, the team are confident that a low-cost solution to bad hair is in our future.