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

STEFFOLANI, M. E.; VILLACORTA P; MORALES-SORIANO, E.R.; REPO-CARRASCO, R.; LEÓN, A. E.; PÉREZ, G. T.

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 andphysico-chemical characteristicsas well as the functional properties of quinoa protein isolates (QPI) from different varieties, and to analyzethepossible 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 percentageof over 85%. The comparison of the flours and QPI electrophoretic profiles indicated that the extraction method allowed isolatingpractically all proteins of each variety. All the varieties analyzed had high lysine content, as compared to cereals,andthe essential amino acid content of Bolivian varieties was higherthan varietiesfrom Peru. The pH value affected the solubility and foaming capacity (FC) and the magnitude of effectsdepended 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 holding capacity (OHC) and water holding capacity (WHC) at acid pH; samples from Peru (Cluster 1) had the highest WHC at basic pH and FC at pH 5. QPI presenteda potential as an alternative vegetable protein for food application, in particular for vegetarian and vegan diets.