Release of Angiotensin I-Converting Enzyme Inhibitory Peptides from Flaxseed (Linum usitatissimum L.) Protein under Simulated Gastrointestinal Digestion

• Published in: Journal of agricultural and food chemistry 2011-09, Vol.59 (17), p.9596-9604
• Main Authors: Marambe, Harsha K, Shand, Phyllis J, Wanasundara, Janitha P. D
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Angiotensin-Converting Enzyme Inhibitors - metabolism; Animals; Biological and medical sciences; Digestion; Flax - chemistry; Food Chemistry/Biochemistry; Food industries; Fundamental and applied biological sciences. Psychology; gastrointestinal system; Gastrointestinal Tract - enzymology; inhibitory concentration 50; Intestinal Absorption; linseed; Linum usitatissimum; Peptide Fragments - chemistry; Peptide Fragments - metabolism; Peptide Hydrolases - metabolism; peptides; peptidyl-dipeptidase A; Plant Proteins - metabolism; proteins; Swine
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf202000e

The scope of this study was to determine the ability of flaxseed (Linum usitatissimum L.) proteins to release angiotensin I-converting enzyme inhibitory (ACEI) peptides during simulated gastrointestinal (GI) digestion using a static (SM; no absorption in the intestinal phase) and a dynamic model (DM; simultaneous absorption of digested products in the intestinal phase via passive diffusion). Gastric and gastric + small intestinal digests of flaxseed proteins of both models possessed ACEI activity. The ACEI activity of the gastric + small intestinal digest in the DM (IC50 unabsorbed, 0.05 mg N/mL; IC50 absorbed, 0.04 mg N/mL) was significantly higher (p < 0.05) than that of the SM (IC50, 0.39 mg N/mL). Two peptides, a pentapeptide (Trp-Asn-Ile/Leu-Asn-Ala) and a hexapeptide (Asn-Ile/Leu-Asp-Thr-Asp-Ile/Leu), were identified in the most active ACEI fraction (0.5–1 kDa) of the absorbable flaxseed protein digest by de novo sequencing.