Detection of the lunasin peptide in oats (Avena sativa L)

• Published in: Journal of cereal science 2013-05, Vol.57 (3), p.319-324
• Main Authors: Nakurte, Ilva, Kirhnere, Inga, Namniece, Jana, Saleniece, Kristine, Krigere, Liga, Mekss, Peteris, Vicupe, Zaiga, Bleidere, Mara, Legzdina, Linda, Muceniece, Ruta
• Format: Article
• Language: English
• Subjects: antioxidant activity; Avena sativa; barley; beta-glucans; genotype; LC–MS/MS; Lunasin; Oat genotypes; oats; rye; starch; triticale; wheat
• ISSN: 0733-5210; 1095-9963
• DOI: 10.1016/j.jcs.2012.12.008

We report the first discovery of lunasin in oats (Avena sativa L). Lunasin is a novel cancer preventive, anti-inflammatory and cholesterol-reducing peptide originally isolated from soy and later found in cereals (barley, rye, wheat, triticale). Lunasin was detected in oats using LC–MS/MS analysis. The chromatograms and mass spectra of lunasin isolated from five oat genotypes were compared with those of the synthetic lunasin peptide. We measured the lunasin content in harvests of two years and found that all tested oat genotypes contained the lunasin peptide. However, we observed genotype-related fluctuations in the lunasin content. Notably, the middle early oat variety ‘Ivory’ contained the highest and the most stable lunasin level at 0.197 ± 0.01 mg per g of grain in year 2010 and 0.195 ± 0.009 mg per g of grain in 2011. We also characterized the selected oat genotypes by measuring the contents of protein, β-glucans, fat, starch and moisture in the grains. However, we did not find correlation between lunasin and protein, and β-glucan content. Lunasin isolated from oat showed similar to the synthetic lunasin antioxidant effects. The detection of lunasin complements a list of bioactive compounds present in oats and strengthens recommendations to use oat products. ► Lunasin was discovered in oat (Avena sativa L). ► We report first data of lunasin content in oat genotypes. ► Lunasin content in oat changes genotype-dependently during different years. ► Lunasin content in oat is comparable with that in barley, wheat and rye. ► Lunasin isolated from oat exerts antioxidant activity.