Proteína de huauzontle (Chenopodium nuttalliae Saff.): composición, estructura, propiedades fisicoquímicas y funcionales

Abstract

The objective of this work was to obtain and evaluate a huauzontle seed protein isolate (Chenopodium nuttalliae Saff.) with respect to its nutritional quality, physicochemical and techno-functional properties. Huauzontle seed protein isolate (APH) was obtained by isoelectric precipitation. The nutritional quality of APH was denoted by its high content in most of the essential amino acids and its high digestibility (83.0 ± 0.2 %). Fourier transform infrared spectra report that the relative proportion of α-helix and β-sheet varied with pH. SDS-PAGE showed that APH is composed of albumin and globulins. The water holding capacity (3.3 ± 0.2 g/g APH ) was similar to that reported for other pseudo-cereals. The foaming capacity (FC) and foam stability (FS) were dependent on the concentration of APH. Foams formed with 3 % APH remained stable after 1 hour at room temperature. This was in agreement with the surface tension analysis where a concentration of 3% of APH led to a strong decrease in the values recorded during the first minutes. The rheological properties of 15 % gels at pH 7.0 and 9.0 showed that the storage modulus dominated the loss modulus during the heating-cooling ramp. A percentage of deformation (~60 %) promoted the crossover of the modules in gels formed at pH 9.0. These results clearly show that APH has high nutritional quality and techno-functional properties suitable for use in divers food systems.