3D printing fortified pea-based snacks with precise vitamin dosing by binder jetting

This paper evaluates and compares two viable approaches for on-demand fortification of pea-based snacks using binder jet 3D printing. Thiamine hydrochloride was added to an aqueous binder solution that selectively joins the pea flour layer-by-layer. Three thiamine levels, namely, 0.5, 1, and 1.5 mg, were targeted based on recommended dietary allowances for toddlers, young females, and pregnant females. The final amount of thiamine dosed into the sample depends on the concentration of thiamine in the binder solution and the total amount of thiamine solution dispensed. In the first approach, the amount of solution dispensed was fixed but the thiamine concentration was adjusted for each target dose level. In the second approach, the thiamine concentration in the binder solution was fixed, but the amount of thiamine solution dispensed was varied. Varying amounts of binder solution containing no thiamine was also dispensed to maintain the same level of binder saturation and consequently the mechanical properties. Overall, the second approach had an average dosing accuracy of 94%, which was 3% higher than that of the first approach. In practice, the second approach is also more versatile and preferred as only one thiamine solution is required. For both schemes, the compressive modulus and strength of the baked samples were comparable to those of shortbread, but the amount of thiamine decreased by about 14% after baking, attributed to thermal degradation. The thiamine amount in the baked samples did not change further when vacuum-packed and stored in the dark for one week.