Effects of different polyphenols on the structural, physicochemical, digestive and 3D printing properties of mashed potatoes

This study investigated the effects of ferulic acid (FA), tannic acid (TA), and rutin (RU) at 0–7.5 % concentrations (based on raw potato flour) on 3D-printed mashed potatoes (MP). Incorporation of 0–4.5 % polyphenols enhanced the extrusion characteristics and printing accuracy, while 7.5 % addition caused significant collapse owing to weakened self-supporting ability. The formation of non-inclusive polyphenol-starch complexes through hydrogen bonding disrupted the short-term ordered structure and double-helix structure of potato starch, reducing the crystallinity and gel strength. Polyphenols enhanced the solubility, water-holding capacity, and digestion resistance while reducing viscoelasticity and swelling capacity, effectively inhibiting starch retrogradation. The action sequence followed TA > RU > FA, correlating with the number of hydroxyl groups. TA with high molecular weight exhibited the most significant impact on the properties of MP, showing the best anti-digestibility and extrusion modulation effects, while 4.5 % TA is suitable for the production of 3D printed MP with lower digestibility.