TY - JOUR

T1 - Valorization of pomegranate husk - Integration of extraction with nanofiltration for concentrated polyphenols recovery

AU - Papaioannou, Emmanouil

AU - Mitrouli, Soultana

AU - Patsios, Sotiris

AU - Kazakli, Maria

AU - Karabelas, Anastasios

N1 - This is the author’s version of a work that was accepted for publication in Journal of Environmental Chemical Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Environmental Chemical Engineering, 8,4, 2020 DOI: 10.1016/j.jece.2020.103951

PY - 2020/8/1

Y1 - 2020/8/1

N2 - A process development study is reported, involving water-based extraction of polyphenols from pomegranate husk and their subsequent membrane concentration. Aiming to optimize extraction, various experimental conditions were investigated, including extraction duration, solid to liquid ratio (2-14 % w/v dry weight), extraction temperature, number of sequential extraction stages (single, double and triple) and type of solvent. It was found that two extraction stages (90 min each) under a solid to water ratio of 3% w/v at 30 °C, were sufficient for obtaining a yield of 85% of total polyphenols from the husk. Subsequently, nanofiltration (NF) was used to concentrate the polyphenols extracts by a volume concentration factor (VCF) of three. Two main process parameters, namely pressure (4-14 bar) and pH (4-8), were examined at constant temperature 30◦C, in batch concentration mode. Results show near optimum NF-membrane performance, with high total polyphenols retention (≥ 98%) at 10 bar pressure and pH 6. Interestingly, the NF-membrane, used for up to 10 filtration batches, exhibited satisfactory flux without intermediate cleaning, suggesting that it could be employed for an extended period. Prospects and challenges are discussed for further process development and practical application.

AB - A process development study is reported, involving water-based extraction of polyphenols from pomegranate husk and their subsequent membrane concentration. Aiming to optimize extraction, various experimental conditions were investigated, including extraction duration, solid to liquid ratio (2-14 % w/v dry weight), extraction temperature, number of sequential extraction stages (single, double and triple) and type of solvent. It was found that two extraction stages (90 min each) under a solid to water ratio of 3% w/v at 30 °C, were sufficient for obtaining a yield of 85% of total polyphenols from the husk. Subsequently, nanofiltration (NF) was used to concentrate the polyphenols extracts by a volume concentration factor (VCF) of three. Two main process parameters, namely pressure (4-14 bar) and pH (4-8), were examined at constant temperature 30◦C, in batch concentration mode. Results show near optimum NF-membrane performance, with high total polyphenols retention (≥ 98%) at 10 bar pressure and pH 6. Interestingly, the NF-membrane, used for up to 10 filtration batches, exhibited satisfactory flux without intermediate cleaning, suggesting that it could be employed for an extended period. Prospects and challenges are discussed for further process development and practical application.

KW - pomegranate phytochemicals

KW - agri-food wastes valorization

KW - aqueous extraction

KW - polyphenols nanofiltration

KW - polyphenols concentrate

U2 - 10.1016/j.jece.2020.103951

DO - 10.1016/j.jece.2020.103951

M3 - Journal article

VL - 8

JO - Journal of Environmental Chemical Engineering

JF - Journal of Environmental Chemical Engineering

SN - 2213-2929

IS - 4

M1 - 103951

ER -