3D Printability of Yogurt: Effects of Hydroxypropyl Distarch Phosphate Gelatinization Degree in Printing Performance,...

Traditional yogurt cannot be directly 3D printed into shape. This study uses hydroxypropyl distarch phosphate (HPDSP) at varying gelatinization degrees (GDs) to enhance yogurt's 3D printability. By using the gelatinization curve model of HPDSP, the 3D printing forming effects of yogurt ink with varying gelatinization degrees were investigated, and forming mechanism was explored based on rheological properties, microstructure, infrared spectroscopy, fluorescence spectroscopy, and intermolecular interactions. Sensory quality and lactic acid bacteria count were analyzed. The results showed that increasing HPDSP gelatinization degree (G50-G100) elevated the apparent viscosity and storage modulus (G') of the yogurt ink, improving 3D printing accuracy (overall printing deviation rate [OPD] decreased from 69.1% to 0.56%). Printing outcomes were optimal at G80-G100 (p > 0.05). The molecular structure of HPDSP transitioned from an ordered arrangement to a disordered state or short-range ordered structure, interacting with milk proteins through hydrogen bonds and electrostatic interactions to form a denser, more uniform gel network structure, enhancing the self-supporting capability of the 3D-printed products. G80 (processed at 59.6°C) demonstrated optimal printing precision (OPD = 0.93%), sensory acceptability (89 points), and lactic acid bacteria count (LAB count: 8.09 log CFU g^-1), making it the preferred formulation for 3D-printed yogurt. This study expands options for personalized customization in 3D-printed yogurt production. PRACTICAL APPLICATIONS: This study proposes a simplified method for 3D printing yogurt by adding HPDSP and regulating its gelatinization degree. This technology can create products with different patterns and textures by utilizing a small amount of yogurt, thereby diversifying the product range and enabling efficient use of materials. With its straightforward formulation and operation, this approach innovates dietary experiences and improves market competitiveness in on-site personalized yogurt customization and foods surface decoration.