Antioxidant capacity of Mexican chia (Salvia hispanica L.) protein hydrolyzates

Salvia hispanica seeds were defatted by compression and this led to an increase in their fiber and protein contents. Consumption of this fiber improves bowel function and reduces blood glucose and cholesterol levels. Given its amino acids composition, S. hispanica deffated flour can have an antioxidant effect, protect the body from free radicals, and prevent inflammatory diseases. For this study, S. hispanica seeds were pressed with 22.07% of fat, 12.62% of protein, and 36.46% of fiber (d.b.). A protein concentrate was obtained from defatted flour by alkaline solubilization and acid precipitation allowing fiber separation. The concentrate had 77.26% of protein, the isolated fiber had 72.54% of protein. The concentrate was hydrolyzed with Alcalase–Flavourzyme for up to 240 min. The obtained hydrolyzates had equal degrees of hydrolysis (p < 0.05) and molecular weight of 21.99 and 34.16 kDa, corresponding to 11S globulin fractions. The antioxidant activity was measured by β-carotene discoloration, iron reducing antioxidant power and chelation (iron and copper) in hydrolyzates. The degree of hydrolysis and the first three antioxidant analyses showed comparable values (83%). Copper chelation decreased with time (values of 54–38%).