Production of White, Red and Black Quinoa (Chenopodium quinoaWilld Var. Real) Protein Isolates and Its Hydrolysates in Germinated and Non-Germinated Quinoa Samples and Antioxidant Activity Evaluation

PIÑUEL, L.; BOERI, P.; ZUBILLAGA, F; BARRIO D,; TORRETA, J; CRUZ, A; VASQUEZ, G; PINTO, A; CARRILLO, I

Plants

MDPI

Año: 2019

Red, black and white seeds quinoa were germinated at 28 C during 24 (G1), 48 and 72 h(G3). Red quinoa presented a higher percentage of germination with a value of 46% of germinationat 72 h. Quinoa protein isolate (QPI) was obtained by alkaline extraction (pH 8.0) followed byan isoelectric precipitation (pH 4.5) from white, red and black quinoa seeds, germinated QPI-G1or QPI-G3 and non-germinated QPI-NG, Chenopodium quinoa Willd var. Real. QPI-G1, QPI-G3and QPI-NG were subject to a simulated gastric digestion (DG) and in vitro duodenal digestion(DD). The antioxidant activity was evaluated using the 1, 1-diphenyl-2-picryl hydrazyl (DPPH),azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity(ORAC) methods. Gastric and duodenal digest of QPI-NG and QPI-G1 and QPI-G3 from white, redand black quinoa presented antioxidant activity. QPI-G1-DD of white quinoa presented the highestantioxidant activity with a DPPH value of 167.98 moL TE/g of digest, QPI-G1-DD of red quinoa withan ABTS value of 204.86 moL TE/g of digest and QPI-G1-DD of black quinoa with an ORAC valueof 401.42 moL TE/g of digest. QPI-G3-DD of white quinoa presented higher antioxidant activitywith a DPPH value of 186.28 moL TE/g of sample, QPI-G3-DD of red quinoa with an ABTS value of144.06 moL TE/g of digest and QPI-G3-DD of black quinoa with an ORAC value of 395.14 moLTE/g of digest. The inhibition of reactive oxygen species (ROS) production in the zebrafish embryomodel (Danio rerio) was evaluated. Protein profiles of QPI from white, red and black from germinatedquinoa and non-germinated quinoa were similar with proteins between 10 kDa to 100 kDa with thepresence of globulins 11S and 7S and 2S albumins.