As global cosmetics brands move toward 2030 sustainability goals, there is an urgent need to replace synthetic chemicals with natural alternatives while adopting circular economy practices.
Researchers based in Kunming and Shanghai recently made a breakthrough that could address both issues by transforming agricultural waste from the Himalayan region into a high-performance cosmetic ingredient.
This development offers a promising path for B2B suppliers and manufacturers looking to enhance their sustainability credentials while providing consumers with bioactive, clean label products.
From agricultural waste to cosmetic application
Prinsepia utilis Royle is a deciduous shrub that thrives at high altitudes in the Himalayan region. While the plant is already known for its edible oil, which is frequently compared to Mediterranean olive oil, the extraction process typically leaves behind a substantial amount of solid residue. This by-product was previously discarded as agricultural waste.
However, a research team from Yunnan Characteristic Plant Extraction Laboratory, Shanghai Jiyan Bio-Pharmaceutical Development, and East China University of Science and Technology has demonstrated that this residue is a goldmine of functional compounds.
By applying micronisation technology, the scientists converted the raw seed residue into a fine, spherical powder capable of stabilising Pickering emulsions.
The effectiveness of the powder depended heavily on its particle size. During the study, the researchers used a ball mill to reduce the raw residue from an average size of approximately 61 microns down to a much finer 20 microns.
They observed that these smaller, spherical particles dispersed more quickly to the oil-water interface, where they formed a dense, protective film around oil droplets. This film prevented the droplets from merging, which is the primary cause of product spoilage in traditional emulsions.
The team noted that the spherical shape of the particles could be particularly beneficial for cosmetic applications, as it would provide a smooth, slippery feeling on the skin, enhancing the overall sensory experience for the end user.
Mechanical advantage of Pickering stabilisers
Traditional creams often rely on synthetic surfactants to prevent oil and water from separating. These surfactants can sometimes cause skin irritation or environmental concerns.
In contrast, a Pickering emulsion uses solid particles to create a physical barrier at the interface between the oil and water phases. This method is gaining traction in the green chemistry sector, as it often requires fewer additives.
The researchers in this study found that their micronised seed powder functioned as an exceptional Pickering stabiliser. As the process involved only mechanical grinding rather than chemical modification, the resulting ingredient remained entirely natural and maintained the parent plant’s inherent biological benefits.
To determine how the powder would perform in real-world formulations, the scientists tested its ability to stabilise five different types of cosmetic oils ranging from non-polar mineral oils to highly polar ethers. The results showed that the micronised seed powder performed best with non-polar oils like squalane and mineral oil.
In these mixtures, the powder formed stable oil-in-water emulsions that remained uniform for more than 28 days.
When they examined the emulsions under a microscope, they saw that the particles did more than just coat the oil droplets — they also formed a three-dimensional network throughout the water phase. This dual-action mechanism provided a robust mechanical barrier that could prevent the product from separating over time.
Natural antioxidants offer a secondary functional benefit
Beyond its role as a stabiliser, the Prinsepia utilis Royle seed powder can add significant therapeutic value to cosmetic formulations. The researchers discovered that the powder was naturally rich in polyphenols and polysaccharides, which are well-known for their health-promoting properties.
These substances endowed the emulsions with powerful antioxidant activity. In lab tests, the team measured the powder’s ability to scavenge free radicals, and found that the antioxidant capacity of the emulsion rose dramatically as the concentration of the seed powder increased.
At a concentration of just 3%, the emulsion achieved a free radical scavenging rate of over 91%.
Its multifunctional nature — a single material providing both structural stability and antioxidant benefits — allows for simplified cosmetic ingredient lists. This minimalistic approach to formulation is a major trend in the beauty industry, as it reduces the risk of skin irritation and appeals to consumers wary of complex chemical cocktails.
The researchers emphasised that the presence of these natural antioxidants could also help protect other easily oxidised active ingredients in a formula, potentially extending the shelf life and efficacy of the final product.
Advancing the circular economy in beauty
Sustainability was a central theme throughout the research project. The team pointed out that the processing of fruits and vegetables alone generates a massive amount of solid waste, accounting for nearly 30% of the total waste in some regions.
Upcycling the Prinsepia utilis Royle residue into a value-added cosmetic ingredient provided a clear example of how the beauty industry could reduce its environmental footprint.
Looking ahead, the research team plans to explore how this micronised seed powder performs in more complex, ready-to-market formulations. While the current study focused on simple oil-and-water mixtures, future tests will involve adding common cosmetic additives, such as preservatives and various fragrances, to ensure the stabiliser remains effective in a commercial environment.
The researchers also expressed a particular interest in applying the powder to products designed for sensitive skin. By combining this natural stabiliser with traditional emulsifiers, they hope to
significantly reduce the total amount of synthetic chemicals required in daily skin care routines.
“The micronised Prinsepia utilis Royle seed powder represented a promising and sustainable ingredient for next-generation cosmetic formulations. Its ability to provide long-term stability while delivering high levels of antioxidant protection could make it a competitive alternative to synthetic stabilisers,” they concluded.
Source: Cosmetics
“Micronized Prinsepia utilis Royle Seed Powder as a Natural, Antioxidant-Enriched Pickering Stabilizer for Green Cosmetic Emulsions”
https://doi.org/10.3390/cosmetics12060281
Authors: Ye Chuan Jun, et al
