In the present study,
quinoa
protein hydrolyzate was prepared using alcalase and pepsin enzymes. Then, the effect of different temperatures (40, 45, 50, and 55°C), periods of time (60, 120, 150, 180, and 210 min), and the ratio of enzyme to substrate (30, 60, and 90 Anson unit/kg protein) on degree of hydrolysis were examined. Also, the antioxidant activity was assessed using DPPH radical scavenging test, and investigated using a completely randomized design. According to results, the optimum condition to produce hydrolyzates with the highest degree of hydrolysis (24.65%) was 55°C, 210 min, with ratio of enzyme to substrate of 60 Anson unit/kg protein, The highest antioxidant activity (35.44) of protein hydrolyzed was achieved at 150 min, 50°C, and the ratio of enzyme to substrate 60 (Anson unit/kg protein). Moreover, there was no significant (
p
> 0.05) between the level of hydrolysis and the antioxidant activity was among different time and temperatures. In conclusion, the peptide derived from
quinoa
protein showed a sufficient antioxidant activity to be incorporated in food products.
Quinoa seed, as a rich source of protein with strong antioxidant properties, plays an important role in improving consumers’ nutrition. This study was aimed at comparing the antimicrobial activity of peptides from quinoa hydrolysed proteins (QHP) on Streptococcus pyogenes as a Gram-positive and Escherichia coli as a Gram-negative bacterium with gentamicin antibiotic as a positive control. Different enzymatic ratios of pepsin and alcalase (30–90 AU/kg protein) at different temperatures (50–55°C) and times (150–210 min) were used to determine the optimal conditions for peptide hydrolysis with the highest antimicrobial properties. Similar to gentamicin, the maximum growth inhibition zones were 11.88 ± 0.37 mm and 12.49 ± 0.58 mm for S. pyogenes and E. coli, respectively, with an enzyme/substrate ratio as 60 AU/kg protein, a peptides concentration of 800 μg/ml, and at 50°C for 150 min of hydrolysis. The results showed that QHP has a good inhibitory effect on the bacteria mentioned and can be used as a food preservative.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.