Physico-chemical and functional characterization of protein isolated from different quinoa varieties (Chenopodium quinoa Willd)

STEFFOLANI, ME; VILLACORTA, P; MORALES-SORIANO, ER; REPO-CARRASCO, R; LEÓN, AE; PEREZ, GT

CEREAL CHEMISTRY

AMER ASSOC CEREAL CHEMISTS

Lugar: St. Paul; Año: 2016 vol. 93 p. 275 - 281

0009-0352

The objective of this work was to investigate the nutritional and physico-chemical characteristics as well as the functional properties of quinoa protein isolates (QPI) from different varieties, and to analyze the possible use of such protein isolates in food products. Proteins were isolated by iso-electric precipitation at pH 5 from quinoa flour, and the QPI had a protein percentage of over 85%. The comparison of the flours and QPI electrophoretic profiles indicated that the extraction method allowed isolating practically all proteins of each variety. All the varieties analyzed had high lysine content, as compared to cereals, and the essential amino acid content of Bolivian varieties was higher than varieties from Peru. The pH value affected the solubility and foaming capacity (FC) and the magnitude of effects depended on the variety. Cluster analyses showed a strong influence of variety source and amino acid composition on protein physico-chemical and functional properties; samples from Bolivia (Cluster 2) were characterized as having the highest thermal stability, oil binding capacity (OBC) and water binding capacity (WBC) at acid pH; samples from Peru (Cluster 1) had the highest WBC at basic pH and FC at pH 5. QPI presented a potential as an alternative vegetable protein for food application, in particular for vegetarian and vegan diets.