Enhancing 3D printing performance of O/W emulsions with asparagus fibre

Asparagus fibre recovered from agricultural waste stream can be valorised as a natural ingredient for fibre enrichment in food products. This study investigated the effects of asparagus fibre on the 3D printing performance of oil-in-water (O/W) emulsions as edible inks. Emulsion gels were prepared by either varying the fibre concentration in the aqueous phase or varying the volume fraction of the oil phase. Printability, rheological properties, and microstructure of the samples were systematically evaluated. Our results show increasing fibre concentration (up to 9.9 %w/w) significantly improved 3D printing performance of the inks, which was attributed to their enhanced rheological properties. Interestingly, reducing the oil volume fraction from 72 to 66 %v/v (i.e., fibre concentration was kept at 9.9 %w/w) did not detrimentally influence the 3D printing quality. Microstructural analysis of the emulsions revealed that increasing fibre concentration led to smaller size and different surface morphology of the oil droplets. Fibre particles in the aqueous phase may hinder oil droplet movement, stabilizing emulsions during 3D printing. Our findings give new insights into the development of edible 3D-printed food products via fibre enrichment and oil reduction.