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

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

2025 Chemical Engineering Science Vol. 305 Article Cited by 7 Quartile

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. © 2025 The Authors

Affiliations

Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, NG7 2RD, United Kingdom; Department of Bioprocess Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, 65145, Indonesia; Research Centre for Food Technology and Processing, National Research and Innovation Agency, Yogyakarta, 55861, Indonesia