Chemical composition and nutritional value of seeds of Lupinus luteus L., L. angustifolius L. and new hybrid lines of L. angustifolius L.

Abstract

The aim of the current study was to evaluate the chemical composition, nutritional value, fatty acid composition, macro(Na, Mg, K, Ca) and microelements, including essential (Cr, Mn, Co, Ni, Fe, Zn, Se and Cu) and nonessential (Al, As, Sr, Cd, Pb and Ag) elements, in the seeds of the yellow lupine (Lupinus luteus L.) variety ‘Vilciai’, the narrow-leaved lupine (L. angustifolius L.) variety ‘Vilniai’ and the six new hybrid lines (Nos. 1700, 1701, 1703, 1072, 1734 and 1800) bred from the narrow-leaved lupine (L. angustifolius) in Lithuania. Gas chromatography with a flame ionization detector showed that oleic and linoleic unsaturated fatty acids were the dominant fatty acids in lupine seeds, which accounted for on average 33.2% and 38.4% of the total fatty acids, respectively. The highest protein content, measured by the Kjeldahl method, was detected in the ‘Vilciai’ lupine seeds (40.8%) and for the tested hybrid lines it was by 20.1–25.7% lower. The content of alkaloids in the seeds of lupine varieties ‘Vilciai’ and ‘Vilniai’ was 0.021% and 0.030%, respectively; while in the new hybrid lines of L. angustifolius the content of alkaloids was less and varied from 0.011% to 0.012%. Analysis of macroand microelements of lupine seeds performed using inductively coupled plasma mass spectrometry revealed that the new hybrid lines had the highest content of Na (from 1.07 to 1.19 mg g-1 dry mass (d.m.), respectively), whereas the highest content of Mg and K was found in ‘Vilciai’ seeds (3.44 and 13.9 mg g-1 d.m., respectively). Among the L. angustifolius hybrid lines tested, the highest content of Mg and K in the seeds was determined for the four hybrid lines Nos. 1701, 1703, 1072 and 1734. The highest contents of Mn, Fe, Zn and Se were observed in ‘Vilciai’ seeds (147.65, 73.52, 59.84 and 0.13 μg g-1 d.m., respectively). The concentration of nonessential elements in the tested lupine seeds was far below the levels that cause a health risk.