Increasing market demand for sustainable, environmentally friendly edible film materials has called for the development of new customizable production methods utilizing emerging technologies such as 3D printing. We hereby report a new method to generate functional edible soy protein isolate films prepared from three types of soybeans (AR-R11-7999, MO-S17-17168, and MO-S17-19874R) using an innovative 3D printing technology. The protein contents in AR-R11-7999, MO-S17-17168, and MO-S17-19874R soybean meals and their corresponding protein isolates were 40.0, 39.1, and 39.9; and 84.5, 84.7, and 87.3 % (w/w, dry basis), respectively. Response surface methodology was used to maximize the tensile and puncture strength and minimize the thickness of the 3D-printed edible films using protein concentration, plasticizer concentration (glycerol), and drying time as the independent variables. The optimized film production conditions were determined as soy protein concentration: 8.91%, plasticizer concentration: 3.00%, and drying time: 3.98 h with a desirability value of 0.7428. The optimized conditions were then successfully verified with the original soybean lot with a nonsignificant difference in physical properties. At the optimized conditions, the 3D-printed edible films using three soybean lots revealed: 0.108-0.114 mm thickness; 14.79-16.07 MPa tensile strength; 6.97-8.20 N puncture strength; 90.81-91.53, −1.89 to −1.31, and 14.85-17.25 were color parameters L*, a*, and b*, respectively; 1.22-1.36 g/cm 3 density; and 104.4-105.7% elongation at break ratio (%).
K E Y W O R D Sprotein, packaging, physical properties, plasticizer, polyphenols, 3D printing, edible films, Soybean protein, Physical and textural properties Practical Application: Edible soy protein films produced by an extrusion-based 3D printing approach are highly customizable and precise, and could be produced at an industrial scale. This newly produced environment-friendly soy protein-based edible film can serve as an alternate packaging to synthetic plastics 4808