Effect of 3D printing and traditional molding on phenolic compounds and antioxidant activity in steamed bread.

The production process of fermented black wheat steamed bread is closely related to the overall quality and nutritional content. In this study, we investigated the accuracy, product texture profile and antioxidant activity of fermented black wheat steamed bread samples produced by piston and spiral three-dimensional (3D) printers. The steaming process generally increased the total phenolic content and flavonoid content of the samples. The spiral 3D printer obtained samples with higher accuracy, total phenolic content up to 1960.43 Mg GAE/kg, and higher cellular antioxidant activity (CAA) content. The samples printed by the piston 3D printer showed higher total flavonoid content (575.75 Mg QE/kg), 2, 2'-azobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) values and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) values. This study shows that antioxidant-rich health foods can be prepared using 3D printed black wheat flour. The choice of 3D printing method affects the overall quality and nutritional content of the final product.