Hydrolyzed Keratin is a chemical compound derived from keratin obtained by chemical and non-chemical processes, a key structural material making up hair, nails, and the outer layer of human skin. It's often used in hair and skin care products due to its protective and restorative properties. Since keratins are difficult to solubilize, after grinding this ingredient can be produced by hydrolysis via enzymes, acids or other hydrolysis methods.

The name defines the structure of the molecule:

• Hydrolyzed. This term refers to the process of hydrolysis, where a compound is broken down by reacting with water. In the context of proteins such as keratin, hydrolysis can break down the protein into smaller units, or peptides.
• Keratin is a type of protein, a key structural material in the outer layer of human skin, as well as in hair and nails. Keratin proteins are formed by amino acid chains and are known for their strength and resilience.

The synthesis process takes place in several stages:

• Extraction of keratin by treating the source material with a solution of a reducing agent, such as thioglycolic acid, to break the disulfide bridges in keratin and make it soluble.
• Hydrolysis. Soluble keratin is hydrolyzed, typically using an acid or enzyme, to break it down into smaller peptide fragments. This process makes keratin more easily absorbed by the skin and hair.

What it is used for and where

Cosmetics  

Hair conditioning agent. A large number of ingredients with specific purposes can co-exist in a hair shampoo: cleansers, conditioners, thickeners, mattifying agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersing agents that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioners includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners.

Nail Conditioning agent. It is an agent that creates protection against harmful or chemical substances by strengthening the nail structure against external elements and can repair any chipping, cracking or brittle nails. It helps keep the nail's outer layer and keratin protein in good condition. It can also prevent cracking and peeling of the nail.

Skin conditioning agent - Miscellaneous.  This ingredient has the task of modifying the condition of the skin when it is damaged or dry by reducing its flakiness and restoring its elasticity.

Some important study

Hair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation. The major function of keratin cuticle is to protect the cortex of the hair from damage caused by several factors including heat, chemicals and daily maintenance. Keratin is a fibrous and insoluble protein with excellent mechanical properties. The major function of keratin cuticle is to protect the cortex of the hair from damage caused by several factors including heat, chemicals and daily maintenance. Keratin is a fibrous and insoluble protein with excellent mechanical properties (1).

In this work, the effect of hydrolyzed keratin on the properties of soy protein-based films was analyzed when different manufacture processes were employed. It is widely known that the processing method selected can affect the film properties as a function of the structure obtained during the film formation. Therefore, the assessment of hydrolyzed keratin/soy protein films processed by casting and compression moulding was carried out by means of the analysis of physicochemical, thermal, mechanical, optical and surface properties. It was observed that the incorporation of hydrolyzed keratin, obtained from a simpler, environmentally friendlier and more sustainable extraction method, resulted in the improvement of the thermal stability of the films, irrespective of the processing method employed. Moreover, the films processed by compression moulding showed enhanced tensile strength, which increased with the incorporation of hydrolyzed keratin due to the formation of disulfide bonds (2).

Molecular Formula : C₂H₂BrClO₂

Molecular Weight : 173.39308

CAS: 65997-21-9    73049-73-7

Synonyms : 

• Keratin hydrolyzate
• Keratin, hydrolyzed
• Keratins, cattle horn, saponified and neutralized
• Cattle hair

EINECS 274-001-1

References_______________________________________________________________________

(1) Villa AL, Aragão MR, Dos Santos EP, Mazotto AM, Zingali RB, de Souza EP, Vermelho AB. Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber.   BMC Biotechnol. 2013 Feb 18;13:15. doi: 10.1186/1472-6750-13-15

(2) Garrido T, Leceta I, de la Caba K, Guerrero P. Chicken feathers as a natural source of sulphur to develop sustainable protein films with enhanced properties. Int J Biol Macromol. 2017 Aug 8. pii: S0141-8130(17)32489-3. doi: 10.1016/j.ijbiomac.2017.08.043.