1. What upcycling is and why it fits sustainable cosmetics
In cosmetics, upcycling means transforming co-products or by-products (for example, peels, seeds, pulps, or oilseed cakes) into ingredients with functional value, while maintaining an industrial approach: traceability, quality control, reproducibility, and scale-up feasibility. It is not just about reuse, but about turning residual streams into an active ingredient with measurable performance and a clear technical specification.
- Operational impact: reduces waste and improves raw material utilisation.
- Innovation impact: enables new extract profiles, fractions, and combinations of bioactives.
- Brand and market impact: supports a narrative of verifiable sustainability.
2. Plant co-products with high bioactive potential
Many by-products generated by the agri-food industry concentrate compounds of cosmetic interest. The key is to identify which fraction delivers value (aroma, antioxidants, functional lipids, pigments, etc.) and which process can recover it without compromising safety, stability, or scalability.
| Plant by-product | Compounds of interest | Common cosmetic benefits |
|---|---|---|
| Citrus peels | Flavonoids, vitamin C, terpenes (limonene, linalool) | Antioxidant, brightening, anti-pollution |
| Oilseed cakes (almond, walnut, hazelnut) | Unsaponifiable lipids, tocopherols, phenolics | Hydration, skin barrier support, protective action |
| Aromatic plants (rosemary, thyme, sage, lavender) | Terpenes, carnosol, rosmarinic acid, antimicrobial compounds | Soothing, antioxidant, anti-inflammatory, natural preservative support |
| Grape or berry residues | Anthocyanins, tannins, ellagic acid | Protection against free radicals, regenerative effect, anti-ageing claim support |
3. How to select raw materials: technical and business criteria
For upcycling to truly act as a driver of sustainable cosmetics, raw material selection cannot be based only on a compelling story. It must sustain an industrial case: availability, supply stability, and standardisation potential. This approach avoids “nice” concepts that are not viable at scale.
- Availability and continuity: volume, seasonality, and logistics of the by-product.
- Variability: expected range of key compounds and the strategy to standardise.
- Safety and compliance: risks from contaminants, allergens, pesticides, or traces.
- Application fit: end-product type (face, body, hair), sensory profile, and claims.
- Scalability and total cost: pre-treatment, storage, yields, and energy costs.
4. Extraction technology: how to choose a cleaner process
In a context where natural cosmetics must demonstrate efficacy, purity, and sustainability, extraction technology becomes a decisive factor. Recovering functional actives from plant by-products requires methods that preserve bioactivity, reduce process footprint, and simplify downstream operations (purification, solvent removal, effluent treatment).
- Process “cleanliness” profile: less solvent use, fewer steps, and less waste generated.
- Active protection: mild conditions to avoid thermal or oxidative degradation.
- Reproducibility: ability to control parameters and deliver consistent batches.
- Compatibility with certifications and positioning: alignment with natural origin and responsible formulation.
5. Supercritical CO₂: purity, performance, and alignment with responsible formulation
Supercritical CO₂ extraction has established itself as a particularly suitable option when the goal is to recover functional fractions with a “clean” chemical profile and no solvent residues. From an operational standpoint, it supports industrialisation with robust process control and a technical narrative aligned with sustainable cosmetics.
Solvent-free extraction: chemical purity and respect for the active
Supercritical CO₂ acts as a natural, inert solvent that leaves no residues. Unlike methods based on organic solvents, it reduces the need for removal steps and minimises by-products that could affect ingredient safety or sensory profile. This is critical in cosmetics, where the absence of traces and batch consistency are direct levers of quality.
- Chemical integrity of the active
- Stability of the natural aroma
- Compatibility with organic or natural-origin certifications
- Batch-to-batch reproducibility
Mild conditions: preserving aromatic notes and bioactivity
One of the main challenges when valorising co-products is preserving sensitive compounds such as terpenes, polyphenols, unsaponifiable lipids, carotenoids, or vitamins. By operating at moderate temperatures and with low oxygen presence, supercritical CO₂ helps reduce thermal and oxidative degradation, improving the functional quality of the extract.
Adjustable selectivity: tailored fractions
By adjusting pressure, temperature, and flow rate, extraction can be directed towards specific families of compounds. This control enables a “fraction-based” strategy: designing ingredients with a clear specification (for example, an aromatic fraction versus a functional lipid fraction) and, as a result, strengthening the technical robustness of the claim.
- Aromatic terpenes (limonene, linalool, citronellol) for perfumery and essential oils
- Functional oils rich in tocopherols or plant-derived squalene for hydrating and protective formulas
- Antioxidant extracts from aromatic plants (rosemary, sage, thyme)
- Light lipid fractions for use as high-purity carrier oils
