VALPRO Path research explores prospects of blue lupin protein isolates

A research paper published by the VALPRO Path team in an open-access journal explains how blue lupin can be used to obtain protein isolates with interesting nutritional and functional properties.

The work titled “Evaluation of protein composition and functionality of lupin protein isolates extracted from different blue lupin (Lupinus angustifolius) cultivars” appeared in the journal Current Research in Food Science.

It describes the composition and functionality of protein isolates obtained from different narrow-leaf lupin genotypes. The research was conducted on 22 blue lupin varieties, both commercial and experimental, selected from the collection of commercial and experimental cultivars grown in controlled conditions.

The researchers looked at the protein composition of the isolates, focusing on the content of storage proteins α-conglutin and β-conglutin, and analyzed the nutritional and functional properties of these proteins.

According to the results of the paper:

• Protein isolates from all 22 varieties had α-conglutin:total α + β conglutin ratios ranging from more than 53%.
• Six of the most promising varieties were selected for further studies on the composition and properties of lupin protein isolates.
• Alkaloid content in protein isolates was reduced to less than 200 mg/kg with increased protein content.
• Protein isolates showed similar trends in solubility in different pH environments, despite differences in the initial protein composition.
• The solubility of protein isolates obtained in this study was higher than that of the commercial lupin protein isolate used for comparison, which may be due to the milder conditions of isolation used in this study.
• The content of leucine and lysine was the highest among the essential amino acids, with methionine being the limiting amino acid.

Surface activity of the isolates in the interfacial layers of aqueous-oil systems did not show any significant differences, despite the differences in conglutin content.

This study highlights the prospects for using blue lupin as a source of high-quality plant protein and provides insights into the relationship between the composition of lupin varieties and the properties of the protein isolates obtained from them. It also fits into the broader context of the VALPRO Path project, which studies and promotes the alternative potential of Europe’s plant protein crops.