Isolation, functional properties and potential use of protein preparations from lupin

Protein isolates were prepared by extraction with diluted NaOH (resulting the highest yield) and precipitation with HCI from lupin seeds grown in Egypt and Hungary. Protein content, amino acid composition, biological value and functional properties of isolates were studied. The proteins were high in lysine but relatively low in sulfur-containing amino acids. Good solubility and moderate emulsifying, foaming and gel-forming properties of isolates were observed. Enrichment of fruit-and vegetable-based baby foods with these isolates resulted in products with excellent organoleptic properties and moderate biological value. Additional enrichment with small quantities of methionine increased significantly the biological value without any negative changes of organoleptic characteristics. Cette etude evalue les proprietes fonctionnelles d'isolat de proteines de lupin et les possibilites de les utiliser pour enrichir les produits alimentaires pour nourrissons a base de legumes et de fruits. Les proteines isolees sont riches en lysine mais relativement pauvres en acides amines soufres. De bonnes proprietes de solubilite et des proprietes moderees d'emulsification, de moussage et de gelification sont observees. Les produits infantiles enrichis avec ces isolats presentent d'excellentes proprietes organoleptiques et leur valeur biologique peut etre amelioree par l'addition de methionine.