Abstract:This research was performed to investigate the effect of enzyme preparation on the phenolic substances in quinoa bread,the quality of bread such as color,elasticity,and texture,as well as its effect on nutritional function. In this paper,quinoa was employed as the raw material,and xylanase,fungal amylase,pectinase,and papain were added to quinoa powder and mixed with 30% of gluten flour to make quinoa bread. The texture of bread,free phenols,bound phenols,flavonoid content,and antioxidant activity were measured. The results revealed that compared to the control group,the physicochemical properties of quinoa steamed bread improved with enzyme treatment.Specifically,the fungal amylase group showed 87%,8%,and 96% increase in hardness,elasticity,and chewiness,respectively. However,the papain reduced the hardness,elasticity,and chewiness by 30%,20% and 26%,respectively. The total phenolic content of the bread with papain was increased by 99.23%,whereas,while the pectinase group showed approximately a 32.67% increase in bound polyphenols. The xylanase group had a 25% increase in free flavonoid content,whereas the bound flavonoid content decreased by 17.98%. The DPPH radical scavenging of free and total polyphenol extracts of the bread with papain was increased by 96.67% and 61.60%,whereas the free polyphenols in the papain group exhibited a 32.30% increase in iron ion reduction capability. Fungal amylase enhanced the hardness,elasticity,and chewiness of quinoa steamed bread,while papain released more free phenols,and xylanase released more bound polyphenols,thereby demonstrating antioxidant effects.