Muceniece, R1, Kirhnere, I.2, Nakurte, I.3, Kronberga, A.2, Kokare, A.2, Strazdina, V.4, Vicupe, Z.4, Bleidere, M.4, Legzdina, L.2
1 Faculty of Medicine, University of Latvia, Sarlotes Str. 1a, Riga LV-1001, Latvia
2 State Priekuli Plant Breeding Institute, Zinatnes Str. 1, Priekuli LV-4126, Latvia
3 Faculty of Biology of University of Latvia, Kronvalda bulv. 4, Riga, Latvia
4 State Stende Cereal Breeding Institute, ‘Dizzemes‘, Dizstende LV 3258, Latvia
Lunasin is a novel, cancer-preventive, anti-inflammatory and cholesterol-reducing 43-amino-acid peptide that was originally isolated from soy and is also found in barley, rye and wheat. Obtained bioavailability and thermostability of lunasin after oral administration indicate the reasons for recommending the inclusion of lunasin-containing products in the human diet. Purpose of this study was to compare content of lunasin in different cereal species as well as to evaluate lunasin level in barley grown in organic and conventional farming systems. Additionally, we searched for new lunasin-containing cereals.
Lunasin was detected using liquid chromatography-mass spectrometry and mass spectrometry tandem analysis. Cereal grain samples were collected from field trials under conventional and organic farming in 2010 in Stende (winter wheat and oat) and in Priekuli (winter triticale, rye and spring barley). The number of samples analysed was 5 – 6 per species, except 43 samples for barley.
We found that triticale(X Triticosecale Witt.) was the most lunasin-rich cereal, displaying the lunasin content from 6.46 to 0.42 mg g-1 of grain (breeding lines 0002-26 and 0006-31, respectively). In comparison, the highest lunasin content found in rye (Secale cereale) was 1.5 mg g-1 in variety ‘Dankovske Diament‘, and in the winter wheat (Triticum aestivum) - 0.23 mg g-1 (variety ‘Fredis‘). Oat (Avena sativa L.) variety ‘Ivory’ contained the highest lunasin level of tested oat genotypes (0.197 mg g-1). Measuring the lunasin content in organically and conventionally grown barley (Hordeum vulgare L.), we observed the average level 0.039 and range 0.004 – 0.169 mg g-1.
We report first data of lunasin content in cereal genotypes grown in Northern Europe; it is novelty as previously published data on lunasin in cereals were obtained in genotypes grown in Korea. Moreover, we report the first discovery of lunasin in triticale and oats. The detection of lunasin complements a list of bioactive compounds present in the cereals and strengthens recommendations to use their products as functional foods.
The research has been supported by the European Social Fund co-financed project Nr. 2009/0218/1DP/18.104.22.168.0/09/APIA/VIAA/009.
Key words: lunasin, winter triticale, rye, winter wheat, oat, spring barley