Analytical nutritional characteristics of seed proteins in six wild Lupinus species from Southern Spain

The nutritional characteristics of seed proteins of Spanish wild populations of Lupinus angustifolius, L. cosentinii, L. gredensis, L. hispanicus, L. luteus and L. micranthus have been studied. Protein contents in this genus ranged from 23.8% in L. gredensis to 33.6% in L. luteus. On the one hand, L. cosentinii showed the most balanced amino acid composition, being only deficient in lysine. On the other hand, L. gredensis showed the worst amino acid composition. The in vitro protein digestibility (IVPD) was high in all species examined, ranging from 82.3% in L. gredensis to 89.0% in L. cosentinii. In addition to the amino acid composition and IVPD, other nutritional parameters, such as amino acid score, calculated biological value, predicted protein efficiency ratio or protein digestibility corrected amino acid score, were studied. These data yielded L. luteus, L. hispanicus and L. cosentinii as the species with seed proteins with the best nutritional properties, similar to those observed in other legumes with recognised high quality proteins, such as soybean. Results confirm the importance of studying wild populations of cultivated and non-cultivated Lupinus species as sources of seeds with good nutritional characteristics.