Edith Cowan University, Research Online, Perth, Western Australia
Doi
Abstract
Lupins are a promising source of protein that can complement soybean-based proteins in food and animal feed. Narrow-leafed lupin (Lupinus angustifolius) is the predominant lupin species cultivated in Australia and Europe. Consumption of lupin products can lead to toxicity in both humans and animals, primarily due to the presence of naturally occurring alkaloid compounds. The aim of the present research was to examine the alkaloid content of commercial narrow-leafed lupin grown in Australia and compare this to wild accessions. Nineteen accessions of narrow-leafed lupin were grown in a growth chamber with a day/night cycle of 18 h of light and 6 h of darkness. An LC-MS/MS-based method was deployed to detect and quantify the main alkaloids in lupins: angustifoline, 13α-hydroxylupanine, (+) lupanine, sparteine, (-) lupinine, isolupanine, and gramine. The alkaloid content in narrow-leafed lupin exhibited a wide variation among different genotypes. Sweet varieties such as Geebung had remarkably low alkaloid content, below 10 mg/kg. Bitter accessions such as P22660 displayed considerably higher alkaloid levels, as high as 20,000 mg/kg. The level of variation of alkaloids observed within lupin grain from different plant replicates of the same cultivars was significantly greater in sweet phenotypes (SD \u3e 100 %) compared to bitter cultivars (SD \u3c 20 %)
