Sustainable and degradable coatings from pectin production co-products
Wageningen University & Research is developing a method to turn spent citrus and apple peels after pectin extraction into glucose-based nanocellulose coating materials for the paper and moulded-fibre industry. The approach uses cellulose microfibrils and nanocrystals that retain residual pectin and hemicelluloses, requiring less purification than classic nanocellulose processes. Target products are functional starch-based coatings for printability, strength, and water or oxygen resistance, supporting replacement of conventional plastic barrier coatings.
Overview
This technology platform converts a major food-processing co-product—spent orange and apple peels left over after pectin extraction—into renewable nanocellulose materials for paper and moulded-fibre packaging coatings. The goal is to provide a sustainable alternative to synthetic barrier coatings currently used for printability, strength, and oxygen/water resistance in packaging. Conventionally, the paper industry depends on chemical or plastic-based functional coatings that are increasingly restricted under European regulations and recycling requirements.
The value proposition lies in using residual pectin and hemicelluloses as functional components instead of removing them. This lowers purification and energy inputs compared to wood-derived nanocellulose, while keeping the co-product stream inside the circular economy. Earlier trials using fruit-processing residues have already shown paper-strengthening effects, supporting the technical feasibility of this route.
Technical specifications
The approach produces two cellulose-based materials with complementary properties:
- Microfibrillated cellulose (MFC): long, thin cellulose fibrils that form network structures and reinforce paper.
- Cellulose nanocrystals (CNC): short crystalline cellulose particles that can produce dense, high-strength coatings.
The intended processing route applies mild mechanical and chemical treatment to the spent peels after the acid extraction step already used in pectin manufacturing, followed by washing, separation, and filtration.
The key innovation under investigation:
- Retaining residual pectin to create a pectin–cellulose fibril composite, which may outperform purified nanocellulose in coating functionality.
- Using the existing pectin-extraction acid step as a natural pretreatment for cellulose recovery.
- Combining CNC and/or MCF with starch to create coating formulations for different paper grades.
Planned testing includes formulation, coating application on different papers, and measurement of the resulting strength and barrier properties.
Technology readiness level
Currently, the technology is at an early-stage research phase. The hypothesis is supported by previous observations of paper strengthening using fruit-processing residue, but the specific spent-peel nanocellulose coating formulation has not yet been experimentally validated.
The next-stage proposed programme includes three work packages: (1) extraction process development and product purification, (2) coating and performance testing on paper, and (3) creation of a process flow sheet and cost-price estimate. Completion of this programme will provide laboratory-scale validation data, a clear production concept, and an initial techno-economic assessment—ready step ahead potential pilot-scale prototyping.
About Wageningen University and Research
Wageningen University & Research is a life sciences–focused public university combined with mission-driven research institutes, integrating fundamental, applied, and field-based R&D at scale. On Wageningen Campus, companies co-locate with WUR teams and use shared pilot plants, advanced analytical labs, and controlled‑environment facilities for rapid prototyping. Being in the Food Valley cluster provides tight links to global corporates, SMEs, and startups through living labs and a strong regional talent pipeline. Research is backed by competitive funding from the Dutch Research Council, European Union programs, and national ministries, alongside significant contract research for industry. A dedicated technology transfer office and campus incubators streamline IP, licensing, and spin‑out formation for corporate partners and entrepreneurs.
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