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Bioactive phytochemicals in flaxseed

with particular emphasis on the secoisolariciresinol oligomer

Johnsson, Pernilla (2009). Bioactive phytochemicals in flaxseed. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2009:57
ISBN 978-91-576-7404-3
[Doctoral thesis]

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Abstract

Flaxseed (Linum usitatissimum L.) is rich in health-promoting bioactive compounds. Among plant foods, flaxseed has the highest content of lignans, mainly in the form of secoisolariciresinol diglucoside (SDG). Flaxseed oil also has a very high concentration of the essential omega-3 fatty acid alpha-linolenic acid (ALA). This thesis presents studies on both SDG and ALA. An HPLC method for quantification of SDG in hydrolysed flaxseed extracts was developed and used to compare the SDG content in 29 flaxseed cultivars (6.1-13.3 mg/g seed, dry weight). Full spectroscopic (NMR) data were obtained for two compounds, 4-O-β-D-glucopyranosyl-p-coumaric acid (CoAG) and 4-O-β-D-glucopyranosyl-ferulic acid, eluting before SDG in the HPLC system developed. NMR analyses provided the first evidence that SDG in flaxseed is bound in a linear oligomeric structure with an average composition of five SDG residues interlinked by four 3-hydroxy-3-methyl glutaric acid residues (average size 4 kDa). Chromatographic (UHPLC, GPC, SPE) and spectroscopic (MALDI-TOF) analyses of seven different flaxseed cultivars showed that the size of the SDG oligomers differed among cultivars depending on seed SDG/CoAG ratios. In attempts to decrease the use of fish-based feeds in aquaculture, vegetable oils are being assessed as replacements for fish oil. However, this has hitherto resulted in decreased levels of the long-chain omega-3 fatty acids (n-3 HUFA) that make fish a healthy food choice for humans. Previous studies have shown that sesamin, a lignan from sesame seed, is able to increase conversion of ALA to n-3 HUFA in rainbow trout (Oncorhynchus mykiss) but less efficiently than expected when flaxseed oil, given its high ALA content, was used. In order to investigate whether high levels of ALA or possibly minor compounds in flaxseed oil could be responsible for the low n-3 HUFA formation, rainbow trout were fed diets containing purified flaxseed triacylglycerols (PFSO) with and without sesamin. However, it was found that PFSO was unable to increase ALA conversion compared with unaltered flaxseed oil and that PSFO with or without sesamin addition had the opposite effect to unaltered flaxseed oil with or without sesamin addition, respectively. The reasons for these effects are discussed.

Authors/Creators:Johnsson, Pernilla
Title:Bioactive phytochemicals in flaxseed
Subtitle:with particular emphasis on the secoisolariciresinol oligomer
Year of publishing :2009
Volume:2009:57
Number of Pages:76
Papers/manuscripts:
NumberReferences
ALLI. Johnsson, P., Kamal-Eldin, A., Lundgren, L.N., Åman, P. (2000). HPLC method for analysis of secoisolariciresinol diglucoside in flaxseeds. Journal of Agricultural and Food Chemistry 48, 5216-5219. II. Johnsson, P., Peerlkamp, N., Kamal-Eldin, A., Andersson, R.E., Andersson, R., Lundgren, L.N., Åman, P. (2002). Polymeric fractions containing phenol glucosides in flaxseed. Food Chemistry 76, 207-212. III. Kamal-Eldin, A., Peerlkamp, N., Johnsson, P., Andersson, R., Andersson, R.E., Lundgren, L.N., Åman, P. (2001). An oligomer from flaxseed composed of secoisolariciresinol diglucoside and 3-hydroxy-3-methyl glutaric acid residues, Phytochemistry 58, 587-590. IV. Johnsson, P., Vincken, J-P., Gruppen, H., Kamal-Eldin, A. The size of the lignan oligomer in flaxseed is influenced by its monomeric constituents (manuscript). V. Johnsson, P., Brännäs, E., Kamal-Eldin, A., Pickova, J. The effect of purified flaxseed triacylglycerols and sesamin on fatty acid composition in white muscle of rainbow trout (Oncorhynchus mykiss) (manuscript).
Place of Publication:Uppsala
ISBN for printed version:978-91-576-7404-3
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:lignans, linseed, essential fatty acids, linoleic acid, oncorhynchus mykiss, feeds, hplc
Keywords:Lignans, HPLC, linseed, rainbow trout, alpha-linolenic acid, n-3 HUFA
URN:NBN:urn:nbn:se:slu:epsilon-2946
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-2946
ID Code:2073
Department:(NL, NJ) > Dept. of Food Science (until 161231)
Deposited By: Pernilla Johnsson
Deposited On:25 Aug 2009 00:00
Metadata Last Modified:02 Dec 2014 10:16

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