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Advancing selectivity in extraction and analysis of bioactive compounds in seaweed and plant-based foods

Gondo, Thamani Freedom LU (2024)
Abstract
A wide range of biomass resources provides significant opportunities to meet
society's needs, such as ensuring food nutritional security, responsible use and
consumption. Seaweed, one of the abundant natural resources along the Swedish
coastline and characterized by rapid growth, has attracted significant interest as a
source of biomass for various industries, including food, biochemical, and biofuel
production. Other interesting plant-based biomass, with a wide range of biochemical
composition, include berries, which are known for their anthocyanin-rich composition. Extraction and analysis are critical steps in recovering valuable
bioactive compounds from biomass, as well as understanding their identity... (More)
A wide range of biomass resources provides significant opportunities to meet
society's needs, such as ensuring food nutritional security, responsible use and
consumption. Seaweed, one of the abundant natural resources along the Swedish
coastline and characterized by rapid growth, has attracted significant interest as a
source of biomass for various industries, including food, biochemical, and biofuel
production. Other interesting plant-based biomass, with a wide range of biochemical
composition, include berries, which are known for their anthocyanin-rich composition. Extraction and analysis are critical steps in recovering valuable
bioactive compounds from biomass, as well as understanding their identity and
concentrations. However, challenges arise due to the diverse chemical properties of
these compounds, such as varying polarity, stability, and matrix interactions.
Additionally, the absence of reference standards for many plant-derived compounds
complicates the analysis. There is a need for robust and sustainable analytical
processes to foster biomass utilization, through both extraction and quantification
of biochemicals. This thesis addresses these challenges by developing quantitative concepts for evaluating extraction performance, focusing on extractability, selectivity, and relative comprehensiveness. Supercritical fluid extraction (SFE) and
chromatographic analysis were utilized for bioactive compounds. The research
began by formulating quantitative descriptors to measure extraction in terms of
extractability, selectivity, and comprehensiveness. Formulas were derived to
estimate selectivity by analysing target components and quantifying potential
interferences. For example, using carbon dioxide (CO2) with 5% ethanol as a co-
solvent in seaweed extraction yielded high selectivity for β-carotene with minimal
interferences. The addition of water increased the extractability and
comprehensiveness of polar compounds but reduced selectivity by co-extracting
undesirable compounds like arsenic. Shortening extraction time to 15 minutes
reduced accumulation of interferences. The second approach involved evaluating extraction selectivity's impact on chromatographic results, investigated by employing multivariate curve resolution (MCR) on liquid chromatography-diode array data from berry matrices. This method highlighted the varying effects of different extraction methods on the quantification of different classes of bioactive compounds. In general, this was a simplified approach crucial for assessing selectivity and improving the reliability of quantification. To address both selectivity and comprehensiveness in analysis of a broad polarity range of bioactive compounds, a strategy combining SFE and supercritical fluid chromatography (SFC) was developed. An SFC method covering compounds of a wide polarity range ( log P of -0.36 to 15.5) was developed. A short (<10 min) and comprehensive analysis method was attained with SFC, while careful fractionation with SFE also demonstrated the potential for reducing matrix complexity before the chromatography. This was particularly shown by a partial least square (PLS) regression model, which predicted the extractability, as well as showing the selectivity in different SFE fractions. Some of the investigations involved assessing the influence of various food processes, such as storage temperatures and fermentation, on the amounts of bioactive compounds. MCR and evolving factor analysis were used to estimate degradation products during storage. In fermentation studies, metabolite changes varied by strain and matrix, which were mainly associated with enhanced extractability and microbial bioconversion. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor West, Caroline, Université d'Orléans
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Selectivity, extractability, comprehensiveness, Bioactive compounds, Supercritical fluids, Interferences
pages
78 pages
publisher
Lund
defense location
Kemicentrum, KC:B
defense date
2024-11-08 09:00:00
ISBN
ISSN 978-91-8096-067-0
ISBN 978-91-8096-066-3
project
Marine food resources for new markets
language
English
LU publication?
yes
id
c2e74839-40e8-48f2-899a-83adefc78b4a
date added to LUP
2024-10-13 23:07:24
date last changed
2025-04-04 14:51:38
@phdthesis{c2e74839-40e8-48f2-899a-83adefc78b4a,
  abstract     = {{A wide range of biomass resources provides significant opportunities to meet<br/>society's needs, such as ensuring food nutritional security, responsible use and<br/>consumption. Seaweed, one of the abundant natural resources along the Swedish<br/>coastline and characterized by rapid growth, has attracted significant interest as a<br/>source of biomass for various industries, including food, biochemical, and biofuel<br/>production. Other interesting plant-based biomass, with a wide range of biochemical<br/>composition, include berries, which are known for their anthocyanin-rich composition. Extraction and analysis are critical steps in recovering valuable<br/>bioactive compounds from biomass, as well as understanding their identity and<br/>concentrations. However, challenges arise due to the diverse chemical properties of<br/>these compounds, such as varying polarity, stability, and matrix interactions.<br/>Additionally, the absence of reference standards for many plant-derived compounds<br/>complicates the analysis. There is a need for robust and sustainable analytical<br/>processes to foster biomass utilization, through both extraction and quantification<br/>of biochemicals. This thesis addresses these challenges by developing quantitative concepts for evaluating extraction performance, focusing on extractability, selectivity, and relative comprehensiveness. Supercritical fluid extraction (SFE) and<br/>chromatographic analysis were utilized for bioactive compounds. The research<br/>began by formulating quantitative descriptors to measure extraction in terms of<br/>extractability, selectivity, and comprehensiveness. Formulas were derived to<br/>estimate selectivity by analysing target components and quantifying potential<br/>interferences. For example, using carbon dioxide (CO2) with 5% ethanol as a co-<br/>solvent in seaweed extraction yielded high selectivity for β-carotene with minimal<br/>interferences. The addition of water increased the extractability and<br/>comprehensiveness of polar compounds but reduced selectivity by co-extracting<br/>undesirable compounds like arsenic. Shortening extraction time to 15 minutes<br/>reduced accumulation of interferences. The second approach involved evaluating extraction selectivity's impact on chromatographic results, investigated by employing multivariate curve resolution (MCR) on liquid chromatography-diode array data from berry matrices. This method highlighted the varying effects of different extraction methods on the quantification of different classes of bioactive compounds. In general, this was a simplified approach crucial for assessing selectivity and improving the reliability of quantification. To address both selectivity and comprehensiveness in analysis of a broad polarity range of bioactive compounds, a strategy combining SFE and supercritical fluid chromatography (SFC) was developed. An SFC method covering compounds of a wide polarity range ( log P of -0.36 to 15.5) was developed. A short (&lt;10 min) and comprehensive analysis method was attained with SFC, while careful fractionation with SFE also demonstrated the potential for reducing matrix complexity before the chromatography. This was particularly shown by a partial least square (PLS) regression model, which predicted the extractability, as well as showing the selectivity in different SFE fractions. Some of the investigations involved assessing the influence of various food processes, such as storage temperatures and fermentation, on the amounts of bioactive compounds. MCR and evolving factor analysis were used to estimate degradation products during storage. In fermentation studies, metabolite changes varied by strain and matrix, which were mainly associated with enhanced extractability and microbial bioconversion.}},
  author       = {{Gondo, Thamani Freedom}},
  isbn         = {{ISSN 978-91-8096-067-0}},
  keywords     = {{Selectivity; extractability; comprehensiveness; Bioactive compounds; Supercritical fluids; Interferences}},
  language     = {{eng}},
  month        = {{10}},
  publisher    = {{Lund}},
  school       = {{Lund University}},
  title        = {{Advancing selectivity in extraction and analysis of bioactive compounds in seaweed and plant-based foods}},
  url          = {{https://lup.lub.lu.se/search/files/197329450/e-nailing_ex_Thamani.pdf}},
  year         = {{2024}},
}