Extraction and chromatography of bioactive compounds in complex samples using supercritical CO2 technology

Bidragets översatta titel : Extraktion och kromatografi av bioaktiva föreningar i komplexa prov med superkritisk CO2-teknik

Said Alhamimi

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

272 Nedladdningar (Pure)

Sammanfattning

Medical doctors and nutritional specialists recommend to eat healthy foods including fruits and vegetables. Cosmetic experts also recommend to use cosmetic products obtained from natural products. The reason behind this is that natural products from plants contain chemical compounds which can promote health and protect our bodies from several diseases. These chemical compounds are called bioactive compounds. They act as antioxidant, antimicrobial and antiinflammation agents in our bodies. These compounds have diverse structures and found among thousands of other compounds in the plant sample. They have different properties, some are fat-like and others are water-like. Some of these compounds are unstable and sensitive to heat and light. These problems always challenge the analytical chemists to find methods selective to target compounds, fast, with high recovery and operate at relatively low temperature.
In this thesis, extraction methods have been developed to offer high solubility, high recovery in a short time, selective to target compounds and sustainable to the environment. Ultrahigh pressure supercritical fluid extraction (UHPSFE) was used to extract oil from Moringa seeds. It is well known that high-pressure causes CO2 molecules to come closer and that increases the density. High density increases the solubility and extractability properties of the fluid and that increases the extraction rate. The amount the oil obtained at 80 MPa was 400 mg/g seeds while at 40 MPa was 278 mg/g seeds. Also, the oil obtained at 80 MPa has high content of poly unsaturated fatty acids PUFAs.
In this thesis, CO2 is added to the liquid solvent in a technique called CO2 expanded liquid extraction (CXLE) to improve the mass transfer and solubility instead of using high temperature. This technique was used to obtain aroma compounds from plant resin (Boswellia Sacra). CXLE can extract the aroma compounds 10 times faster than supercritical fluid extraction (SFE). CXLE incorporated with ultrasound wave showed high and fast recovery of oil from berry seeds compared to CXLE only. The ultrasound wave improved the mass transfer and also allowed the solvent to penetrate into the sample to increase the solubility.
In supercritical fluid chromatography (SFC) the results reveal that some lipid species can interact very strong with the stationary phases which causes broadening of resulted peaks and lose the resolution and efficiency. Presence of β-amino alcohol on the stationary phases caused distortion of the peaks belong to lipids having terminal primary amines. Diol stationary phase showed the highest peak height and resolution for the most of the lipid species. The developed method can resolve more than 15 lipid classes within 11 min.
Lingonberry is rich fruit in bioactive compounds especially polyphenols. Lingonberry can reduce the impact of high fat diet and improve the liver function. Lingonberry suggested to have influence to alter the formation of unhealthy components in the body like sphingolipids (SMs). High level of SMs are associated with development of obesity and diabetes.
Bidragets översatta titel Extraktion och kromatografi av bioaktiva föreningar i komplexa prov med superkritisk CO2-teknik
Originalspråkengelska
Tilldelande institution
  • Centrum för analys och syntes
  • Kemiska institutionen
Handledare
  • Turner, Charlotta, handledare
  • Spégel, Peter, Biträdande handledare
Tilldelningsdatum2018 okt. 12
UtgivningsortLund
Förlag
ISBN (tryckt)9789174225938
ISBN (elektroniskt)9789174225945
StatusPublished - 2018 sep.

Bibliografisk information

Defence details
Date: 2018-10-12
Time: 09:15
Place: Hörsal B, Kemicentrum, Naturvetarvägen 14, Lund
External reviewer(s)
Name: Emmer, Åsa
Title: Professor
Affiliation: KTH Royal Institute of Technology, Department of Chemistry, Stockholm
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Ämnesklassifikation (UKÄ)

  • Naturvetenskap

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