Protein hydrolysis, peptide fractionation and antiradical activity of peptides produced from extruded and non extruded quinoa (Chenopodium quinoa wild) grains.

LOBO, MANUEL OSCAR; SAMMÁN, NORMA C.; RUEDA, JULIO

Cordoba

Congreso; VII Congreso Internacional Ciencia y Tecnología de los Alimentos; 2018

Gobierno de la provincia de Córdoba

The objective of this work was to evaluate the effect of extrusion of quinoa seeds on the protein hydrolysis and radical scavenging activity of different peptide fractions. Quinoa protein isolates were obtained from defatted flour of extruded and non-extruded grains. Isolates were obtained by alkaline solubilisation and acid precipitation, followed by centrifugation and drying in a flux oven at 30ºC until constant weight. Dried isolates were powdered and protein content was determined. Quinoa protein hydrolysis was performed at 50ºC and pH 9.0 on 10mg/mL protein suspension. Alcalase was added to the suspension in ratio enzyme-substrate 1:10 and pH was corrected to 9.0 with NaOH. Reaction dynamic was monitored over 30 minutes and stopped by thermal inactivation of enzyme (80ºC for 10 min). The hydrolysis degree (HD) was calculated using pH-stat method. Then, the slurry was cooled down to room temperature and centrifuged (10 min, 5000g). Polypeptides and peptides in the supernatant were fractionated by ultrafiltration. Fractions of >10; 10-5; 5-3 and