Functional Properties of Lupin Seed ( <i>Lupinus mutabilis</i> ) Proteins and Protein Concentrates

Abstract

ABSTRACT Functional and electrophoretic properties of the seed flour and a protein concentrate prepared by alkaline extraction from lupin seeds ( Lupinus mutabilis , cultivar H‐6) were investigated. SDS‐PAGE indicated presence of 13 and 12 subunits in the seed flour proteins and the protein concentrate, respectively. Lupin protein concentrate had good water and oil absorption and gelation properties. Solubility of lupin proteins was minimum at a pH of 4.0 but increased rapidly beyond pH 5.0. Foaming capacity of the protein concentrate could be improved by increasing concentration as well as by adding NaCl and was influenced by pH and incorporation of certain carbohydrates. Emulsion properties of lupin proteins were concentration and pH dependent. Moist heat improved the in vitro digestibility of the seed proteins. The seed flour as well as the protein concentrate did not have detectable trypsin, chymotrypsin, and α‐amylase inhibitory activities.