Towards a scalable cacao pod husk biorefinery: Understanding the effects of process conditions on phenolic antioxidant extraction and residual solid properties

Dewi, Shinta R.; Stevens, Lee A.; Anwar, Muslih; Mao, Yujie; Ferrari, Rebecca S.; Irvine, Derek J.; Binner, Eleanor R.

Abstract

Cacao pod husk (CPH) is a potential source of phenolic-based antioxidants and lignocellulosic compounds. Sample pretreatments and extraction conditions were investigated to understand their effects on extraction yields and implications for industrial-scale CPH biorefinery. All processing parameters showed significant effects (p-value < 0.001) on extraction yields, where solvent selection and size reduction were the most influential parameters (η2 > 0.92). CPH extracts contained 3.3–215.1 mg GAE/g dw of phenolics, 0.01–0.38 mg Cy3GE/g dw of anthocyanin and 0.86–22.5 mg TE/g dw of antioxidant activity, making it useful as antioxidants. CPH solid residues, rich in lignocellulosic compounds (23 % of lignin, 37 % of cellulose and 22 – 26 % of hemicellulose), volatile matter (62–65 %) and fixed carbon (21–25 %), are promising as pyrolysis or activated carbon precursors. These findings offer recommendations for large-scale extraction, including maximising CPH solid residue for bioenergy and activated carbon production, integrated into CPH biorefinery units.

Citation

Dewi, S. R., Stevens, L. A., Anwar, M., Mao, Y., Ferrari, R. S., Irvine, D. J., & Binner, E. R. (2025). Towards a scalable cacao pod husk biorefinery: Understanding the effects of process conditions on phenolic antioxidant extraction and residual solid properties. Chemical Engineering Science, 305, Article 121171. https://doi.org/10.1016/j.ces.2024.121171

• Journal Article Type: Article
• Acceptance Date: Dec 30, 2024
• Online Publication Date: Dec 31, 2024
• Publication Date: Feb 15, 2025
• Deposit Date: Apr 11, 2025
• Publicly Available Date: Apr 11, 2025
• Journal: Chemical Engineering Science
• Print ISSN: 0009-2509
• Electronic ISSN: 1873-4405
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 305
• Article Number: 121171
• DOI: https://doi.org/10.1016/j.ces.2024.121171
• Public URL: https://nottingham-repository.worktribe.com/output/43800076
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0009250924014714?via%3Dihub