Quantitative and qualitative content of alkaloids in seeds of a narrow-leafed lupin (Lupinus angustifolius L.) collection

Alkaloids represent the main antinutritional factor in lupins. The total content and qualitative composition of four major alkaloids in L. angustifolius L. were analyzed. The material included 329 accessions from the Polish collection divided into three classes of origin: wild lines, cultivars, and other man-made accessions. A very broad differentiation was found in terms of total alkaloid content—from 0.0005 to 2.8752 % of seed dry weight. In most cases, cultivars were characterized by a sharply decreased content of alkaloids, even below 0.01 % of seed dry weight. The average proportions of individual alkaloids were also very differentiated: lupanine—0.98 to 73.0 % of total alkaloid content (mean 46.4 %), 13-hydroxylupanine—15.6–71.1 % (mean 35.6 %), angustifoline—0–49.8 % (mean 15.5 %) and isolupanine—0–34.0 % (mean 2.5 %). The above mean values are probably typical for this species. In some accessions, lupanine and 13-hydroxylupanine accounted for 90–100 % of all major alkaloids. The average content of isolupanie (2.5 % of all alkaloids) allows it to be consider a major alkaloid of L. angustifolius, but quite frequently a ratio below 1 % or even its absence was stated. The three classes of origin were divided into three significantly different groups based on total alkaloid content as well as individual alkaloid content. Among wild lines, high alkaloid accessions were most numerous, but among cultivars it was low alkaloid accessions. The last class also contained numerous accessions with the lowest content of individual alkaloids. The influence of the content of individual alkaloids on total alkaloid content was also investigated in the wild lines and cultivars.