Enzymatic treatment-induced alterations in printing performance of quinoa flours and microbiota-modulating potential of printed products.

Quinoa is a representative pseudocereal widely used in developing gluten-free products for gluten-sensitive people. While enzymatic pretreatment improves the processing performance of pseudocereal flours, the impacts of glycoside hydrolases on the microbiota-modulating potential of quinoa products remain largely unexplored. This study compared the three-dimensional (3D) printing performance of wheat and quinoa flours, as well as quinoa flours treated with α-galactosidase, β-glucanase, or their sequential enzymatic treatment (α-galactosidase followed by β-glucanase), and then evaluated the colonic fermentation properties of the resulting 3D-printed biscuits. Sequential enzymatic treatment increased solubility of quinoa flour (from 52.64% to 60.21%) while reducing its swelling capacity (from 0.81 to 0.63 g/g). Treatments involving β-glucanase and sequential enzymatic treatment increased dough viscosity and modulus, forming strong gel networks that may impede 3D printing extrusion. No significant differences in biscuit hardness or crispness were observed after baking, indicating the baking process diminished formulation-related differences among the biscuits. Furthermore, quinoa biscuits significantly altered bacterial α-diversity and β-diversity compared with wheat biscuits, whereas different enzymatic treatments exerted limited effects on microbial diversity when compared to untreated quinoa flour. Notably, wheat biscuits markedly enriched Anaerostipes, thereby promoting butyrate production. In contrast, quinoa biscuits significantly increased Phascolarctobacterium, Akkermansia, Lachnoclostridium, and Dorea, which were linked to elevated acetate and propionate levels. Meanwhile, enzymatic treatment consistently inhibited Lachnoclostridium, which showed significant and positive relationships with acetate and propionate. Collectively, sequential enzymatic treatment maintained acceptable printability under optimized printing conditions but may compromise the microbiota-modulating potential of quinoa biscuits, suggesting rational application of glycoside hydrolases for developing gluten-free foods.