The Factor of N and P Fertilization Affecting the Concentration of a Nutraceutical Lignan in Flaxseed
As lignans are derived from phenylalanine, an amino acid found in protein, it is logical to ask the question of the effect of nitrogen and/or phosphorus fertilizers on the final concentration of SDG in flax seed.
IPNI-2002-CAN-SK31
11 Mar 2003
2002 Annual Interpretive Summary
Factors Affecting the Concentration of a Nutraceutical Lignan in Flaxseed, 2002
Lignans are a class of naturally occurring plant phenolics with hundreds of structural variations being reported. The predominant lignan in flax seed (Linum usitatissimum) is secoisolariciresinol diglucoside (SDG). While the presence of SDG in flaxseed has been known for almost 50 years, the biological activity of SDG has been mainly studied during the last 10 years. Today, SDG is of interest as it has shown some potential therapeutic benefits in some cancers, heart disease, diabetes and lupus nephritis.
Samples of flaxseed from co-operative evaluation trials in several locations in Manitoba and Saskatchewan have been analyzed for 11 years. In these trials, no added nutrients were applied. It was determined SDG concentrations in fat free meal varied between 0.9 and 3.1% by weight. Variety accounted for most of the variability observed, year was the next factor with less variability associated with location. As SDG is made from an amino acid, phenylalanine, it was of interest to determine if added nutrients could increase the concentration of SDG in flaxseed. Flaxseed samples were obtained from existing field studies with added phosphorus [(P) five rates, two years), nitrogen [(N), four rates, three varieties], N and P (four rates of each) and one study with N, P, K and sulfur [(S) three years, two locations]. In all studies there were no statistical differences in SDG concentration noted with any of the added nutrients. Where there was more than a single variety or there were multi-year studies, some differences were observed for either variety or year. SK-31