Methionine sulfone-containing orbitides, good indicators to evaluate oxidation process of flaxseed oil

Abstract

This study aimed to explore the possibility of using methionine sulfone (Msn)-containing orbitides as indicators to evaluate the oxidation process of flaxseed oils. Results showed that after 4 days' heating, oxidation values slightly increased (p > .05) with significant decrease in methionine (Met)-containing peptides (p < .05) instead of γ-tocopherol (p > .05). However, as oxidation time continues increasing, oxidation values significantly increased (p < .05) with significant reduction of γ-tocopherol (p < .05). It demonstrated that Met-containing peptides were more readily oxidized compared with γ-tocopherol and showed certain antioxidant activity. Besides, high logarithmic correlations were found between oxidation values and Msn-containing orbitides (0.94-1.00), such as between total carbonyl compounds and orbitide [1-8-NαC],[1-MetO₂]-CLE (64.95 lnx - 52.14, R² = 0.99, Dingya23 oil). Therefore, in comparison with common oxidation indices, Msn-containing orbitides may be better indicators for evaluating the oxidation process of flaxseed oil with superior separation efficiency, specific information and high stability.

Keywords: Cyclolinopeptide B (PubChem CID: 10581956); Cyclolinopeptide C (PubChem CID: 100953614); Cyclolinopeptide E (PubChem CID: 100953616); Cyclolinopeptide J (PubChem CID: 102449637); Cyclolinopeptide K (PubChem CID: 102449638); Cyclolinopeptides; Gamma-tocopherol (PubChem CID: 92729); HPLC-MS; Nonpolar carbonyls; Orbitides; Oxidation indicator; Total oxidation value.