Cosmetic ingredients have traditionally been derived from synthetic, plant and/or animal-based materials. With a growing population and declining natural resources availability, sustainability is a critical measurement of innovation. The United Nations’ International Resources Panel has projected that resource use per person will be 71% higher in 2050 than it is today.¹ Increased consumption of natural resource can increase pollution. For example, CO₂ emissions in 2014 increased approximately 90% vs. 1970, mainly from fossil fuel combustion and industrial processes.² As a result, the use of sustainable resources has become increasingly important to consumers who seek naturally-derived, high-performing products.

Croda is committed to being the most sustainable supplier of innovative ingredients to help provide solutions to some of the world’s biggest challenges by 2030. Its strategy is guided by the UN’s Sustainable Development Goals (SDGs) and therefore is committed to be Climate, Land and People Positive by 2030.

To help achieve this, Croda will reduce emissions and all new innovations will be required to contain a minimum of 75% bio-based organic raw materials. This will help to limit a global temperature rise of no more than 1.5ºC.

Croda has introduced a new plant-based biopolymer (INCI: Aqua (and) Hydrolyzed Pea Protein (and) Hydrolyzed Vegetable Protein) that was developed as a vegan-suitable alternative to animal-derived keratin. From its natural sourcing and sustainable production, the new plant-based biopolymer is aligned with 7 SDGs. Driven by the “conscious beauty” trend, consumers are also embracing vegan values and seeking to contribute to a more sustainable world by making responsible purchasing decisions. According to Mintel market research, ethical and cruelty-free treatment of animals and sustainable sourcing are the top conscious claims for personal care products.

Consumers also recognize that keratin, which is the main component of hair, offers many functional benefits for damaged hair that can be rough, difficult to manage and more prone to breakage. The properties of keratin are also well known and have been extensively studied.

This presents an issue for consumers as they desire sustainable, plant-derived ingredients, but do not want to compromise on performance. There is, therefore, a need for a high-performing, vegan suitable alternative to keratin. 

Amino Acid Optimization

Proteins are primarily comprised of amino acids that link sequentially to form peptides which then link to form longer polypeptide chains. It is important to note that the amino acid sequence of a protein determines its three-dimensional structure, and hence it is critical to optimize the profile of the biopolymer derived from plant sources to closely match that of animal-derived keratin. Therefore, the most abundant amino acids found within animal-derived keratin were matched as closely as possible when developing the plant-derived alternative, aside from cystine as demonstrated in Figure 1.



Vegetable proteins contain significantly lower levels of cystine compared to animal-derived keratin. Therefore, it is not possible to directly match the cystine content. However, the plant-based biopolymer contains similar content to the abundant amino acids in animal-derived keratin including arginine, leucine, glutamic acid, serine and aspartic acid.

Hair Strength Evaluation

As a result of optimizing the amino acid profile, the plant-based biopolymer has proven to deliver comparable hair strengthening performance to animal-derived keratin at low usage levels. Tensile testing was performed to assess the hair strengthening performance of the plant-based alternative compared to traditional keratin. Both bleached Type 2 European and bleached Asian hair were treated with conditioner formulations containing either the plant-based biopolymer or animal-derived keratin at an 0.25% active level and a control formulation. Fifty hair fibers were randomly selected from each treatment and evaluated at 50% RH and the results are summarized in Figure 2.


The strength of both Type 2 bleached European and bleached Asian hair significantly improved after treatment with a conditioner containing the plant-based biopolymer as indicated by the significant increase versus the control formulation in the Total Work to Break parameter. The Total Work to Break represents the total energy measured from breaking a hair fiber, as it is the integral area of the tensile stress-strain curve. After treatment with the plant-based biopolymer, the Total Work to Break of bleached European and bleached Asian hair increased 11.7% and 20.7%, respectively; that is, it takes significantly more energy to break the hair fibers as they have become less brittle and stronger after treatment. These results demonstrate that the plant-based biopolymer performs comparably to the animal-derived keratin and demonstrates the benefit of the amino acid profile optimization.


The biopolymer has also demonstrated the ability to increase the resiliency of hair fibers against breakage using the cyclic fatigue test on Type 7 virgin textured hair, which is more fragile than less textured European or Asian hair. Type 7 virgin textured hair was treated with a conditioner formulation containing a 1.0% active level of the plant-based biopolymer along with a control formulation. One hundred fibers were randomly selected from each treatment and evaluated at 50% RH. Under the cyclic fatigue test, each fiber was subjected to a constant deformation at controlled frequency and the results are summarized in Figure 3.

In the cyclic fatigue test, a higher median of cycles to break indicates increased hair strength and less fragility of hair. After treatment with the conditioner containing the plant-based biopolymer, the median value of cycles to break increased, which suggests the hair has become less brittle and stronger after treatment.

Salon Evaluation

Consumer perceivable benefits of the plant-based biopolymer in a conditioner formulation are apparent from a salon evaluation. Conditioner formulations containing either the plant-based biopolymer or animal-derived keratin were evaluated by a trained cosmetologist in a half-head assessment.

From the salon evaluation data summarized in Figure 4, the plant-based biopolymer exhibited similar performance to the animal-derived keratin in a conditioner formulation for many key attributes including wet/dry combability, detangling and strength. Both the cosmetologist and panelists preferred the hair treated with the conditioner formulation containing the plant-based biopolymer to the animal-derived keratin, commenting that the treated hair was more moisturized/hydrated. This proves that in addition to the plant-based biopolymer performing well instrumentally, the benefits are consumer perceivable.

Carbon Footprint Reduction

The most important benefit of the plant-based biopolymer is that it can significantly reduce carbon emissions from use, which provides a positive sustainability impact and contributes to Croda’s commitment to be Climate Positive by 2030. It is known that wool derived keratin has a high carbon footprint due to intensive sheep farming; therefore, switching to the plant-based biopolymer provides the opportunity to lower the carbon footprint without compromising on performance. Based on the carbon footprint associated with the approximate mass of raw materials used, calculations were performed to estimate the amount of carbon savings (CO₂e) from using the plant-based biopolymer. Table 1 illustrates these calculations.

According to Table 1, replacing the animal-derived keratin with Croda’s new plant-based biopolymer can save approximately nine metric tons or 20,000 pounds of carbon (CO₂e) per each metric ton used. This is possible since significantly less carbon is generated from plant or vegetable sources as compared to animal sources. To appreciate the significance of the potential carbon savings from using the plant-based biopolymer in products, additional carbon footprint calculations were performed on typical household tasks such as recycling, electricity consumption and vehicle usage per year.

To save approximately nine metric tons or 20,000 pounds of CO₂e per year, 20 additional households would need to recycle common waste, assuming approximately 1,000 pounds of CO₂e savings from recycling metal, paper, plastic and glass.6 In addition, two households each with a family of four would need to switch to 100% green electricity, assuming approximately 10,000 pounds of CO₂e savings from no longer using standard electricity.⁶ These calculations help to demonstrate how the use of the plant-based biopolymer instead of an animal-derived keratin offers the opportunity to significantly reduce the carbon footprint during manufacture and their use in consumer care products.

Conclusion

In summary, this new plant-based biopolymer was developed as an alternative to traditional animal-derived keratin to address growing consumer demand for ingredients that are sustainable and support ethical and cruelty-free treatment of animals. The plant-based biopolymer is vegan suitable and aligns with seven of the UN’s SDGs. It is also 99% bio-based, readily biodegradable and expected to have low aquatic toxicity.

The optimized amino acid profile of the plant-based biopolymer is comparable to that of animal-derived keratin and is substantive to the hair after treatment. To evaluate the efficacy of the plant-based biopolymer, multiple hair types were tested using both tensile and cyclic fatigue tests. Results demonstrated that treatment with a conditioner containing the plant-based biopolymer led to a significant increase in hair strength on bleached Type 2 European and bleached Asian hair via tensile test and an increase in resiliency on more fragile Type 7 virgin textured hair via cyclic fatigue test.

A salon evaluation was also performed to assess the consumer perceivable benefits of the plant-based biopolymer and confirmed the comparable performance to the animal-derived keratin. Both the cosmetologist and panelists even preferred the conditioner containing the plant-based biopolymer. The instrumental and salon testing determined that the performance of the plant-based biopolymer is comparable and, in some instances, better than the animal-derived keratin.

Replacing the animal-derived keratin with this plant-based biopolymer also significantly reduces carbon footprint, as it has been calculated that approximately nine metric tons of CO2e can be saved from the environment per each metric ton of plant-based biopolymer used. The production of this new plant-based biopolymer therefore contributes to Croda’s commitment to be Climate Positive by 2030. 


About the Author
Kimun Park is a lead applications scientist, Croda Inc. www.crodapersonalcare.com




References

1. Population Matters. (2023, January 5). Resources. https://populationmatters.org/the-facts-resources-consumption/
2. AR5 Climate Change 2014: Mitigation of Climate Change. IPCC. https://www.ipcc.ch/report/ar5/wg3/
3. Brock, P. M. (2013). Greenhouse gas emissions profile for 1 kg of wool produced in the Yass Region, New South Wales: A Life Cycle Assessment approach. AGRIS: International Information System for the Agricultural Science and Technology. https://agris.fao.org/agris-search/search.do?recordID=US201400018380
4. Nette, A. (n.d.). A Comparison of Carbon Footprint and Production Cost of Different Pasta Products Based on Whole Egg and Pea Flour. MDPI. https://www.mdpi.com/2304-8158/5/1/17
5. Ponsioen, T. & Blonk, H. (2011). Case studies for more insight into the methodology and composition of carbon footprints of table potatoes and chips Carbon-footprints-of-table-potatoes-and-chips-July-2011.pdf (amazonaws.com)
6. Household Carbon Footprint Calculator. (n.d.). https://www3.epa.gov/carbon-footprint-calculator/