Flaxseed Cyclolinopeptides: Analysis and Storage Stability

Abstract

Fourteen cyclolinopeptides (CLPs) from flaxseed oil and meal were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The oxidative stability of the cyclolinopeptides was assessed during storage of flaxseed oil and meal. A significant decrease in the amounts of the methionine containing CLPs, namely CLP‐B, CLP‐J and CLP‐M, and a concurrent increase in the amounts of methionine sulfoxide containing CLPs, such as CLP‐C, CLP‐E and CLP‐G were observed. The cyclolinopeptides with two methionine units, CLP‐L and CLP‐M, exhibited the greatest decrease, followed by CLP‐J, the major flaxseed oil bitter taste precursor, and CLP‐B, a biologically active cyclolinopeptide. At the end of the storage period, the amount of the bitter CLP‐E increased fourfold in the oil while the immunosuppressive cyclolinopeptides A remained unchanged. No significant changes in the amount of each of the CLPs were observed in the stored flaxseed meals. A fast and reliable procedure has been developed for quantitative analysis of cyclolinopeptides. Due to the high predisposition of methionine containing cyclolinopeptides to oxidation and the easiness of CLPs’ quantification with the proposed method, it is possible to reliably assess the extent of flaxseed meal and oil oxidation.

Simulated moving bed purification of flaxseed oil orbitides: Unprecedented separation of cyclolinopeptides C and E

“…The novelty of our latest HLPC method developed is in its ability to resolve nine naturally occurring flax orbitides (CLs 2, 3, 5, 6, 8, 10, 13, 14, and 17) in 2.5 min. Like Aladedunye et al [31], CL 1 co-eluted with CL 7 under our HPLC gradient.…”

“…Other authors [31] have reported separation of fourteen known naturally occurring CLs (not including 4, 9, and recently published 18, 19 and 20), but with 1 and 7 co-eluting, using a Kinetex C18 column (2.6 m; 150 mm × 3 mm; Phenomenex, MA). However, the length of their HPLC gradient was 45 min.…”

Flaxseed (Linum usitatissimum L.) oil processing and selected products

“…This was, in part, in agreement with Bhatty (1993) who reported that the trypsin inhibitor levels differed between flax varieties but also found differences between the cyanogenic glycoside content of the same cultivars. In spite of its content of linolenic acid, flaxseed flour arising from cold pressing has excellent oxidative stability (Aladedunye, Sosinska, & Przybylski, 2013). When petroleum ether defatted flaxseed meal was mixed with commercially purchased flaxseed oil it was found that the antioxidant system of the meal confered stability to the oil (Barthet, Klensporf-Pawlik, & Przybylski, 2014).…”

Glycine-Containing Flaxseed Orbitides

“…12 The absence of known flax orbitides 4 and 9 suggested that the flaxseed oil had not yet undergone extensive oxidation. 8,12,23,24 The remaining known flax orbitides 18 and 19 that were recently identified were not detected in this extract probably due to either their occurrence at low concentration and/or the extraction procedure. 11 In addition to the 16 known peptides detected, signals for novel cyclolinopeptides 21, 22, 23, 24, and 25 were also observed ( Table 1).…”