The demand for complementary plant-based protein sources is on the rise. This growth has been driven by population growth, consumer demand and a groundswell of interest in planetary health. The nutrient-dense grain legumes offer a sustainable solution to global food and protein security, among which the lupin seeds stand out owing to their excellent nutritional and nutraceutical properties. These seeds are one of the richest natural sources of protein and fiber and are known to be beneficial in prevention of type-2 diabetes, obesity, and cardiovascular disease. Despite their vast potential lupin seeds are under-utilized as a food ingredient and are mainly grown as green manure and stockfeed. One constraint to widespread adoption of lupin in food products owes to its allergen known content rendering it subject to mandatory labelling on food products in many countries.
Herein, a combination of discovery and quantitative proteome measurements were employed for evaluation of the four major seed storage protein families (α-, β-, δ-, and γ-conglutins) across a panel of 46 genetically diverse narrow-leafed lupin (NLL) varieties. These measurements allowed the differentiation and quantitation of the 16 known conglutin sub-families. Distinct differences were observed in the abundance of conglutins within the analyzed lines, wherein a larger variability was noted for the β- and δ-conglutin proteins. Importantly, the β-conglutin proteins, which are the major allergens from lupin, were substantially reduced within several of the domesticated cultivars, wherein some degree of compensatory elevation of the bioactive γ-conglutin proteins was noted. These potential hypoallergenic lupin genotypes are more suited to be cultivated for food purposes or prioritized in breeding programs for development of lupin varieties with optimal nutritional composition. The outcome of this research opens new vistas for further exploitation of the potential of this emerging legume as a complementary plant-based protein source.