3D printing as an emerging processing technology has been applied in food processing and shows great development potential. It produces products according to the predefined computer model through layer-by-layer deposition, which enables the personalized customization of food products in terms of form and nutrient content. The practical application of this technology faces two bottlenecks, namely the scarcity of available food materials and the poor formability of printed products, and developing a suitable food formulation for 3D printing and optimizing the printing process are key to breaking through the material limitations and technical bottlenecks of 3D printing. In addition, 3D food printing shows great promise in developing easy-to-swallow foods, whose quality is significantly affected by 3D printing materials and post-processing; however, little research has been conducted on this. This paper reviews the influence of the rheology and thermal properties of food materials on the 3D printing effect, the methods used for the optimization of 3D food printing, and the influence of process parameters on the printing effect, and discusses the influence of printing parameters and different post-treatment processes on the development of easy-to-swallow 3D food products. It aims to provide a theoretical basis for the development and optimization of 3D printed food products.

In this study, the effects of pea resistant starch type 3 (RS3) at different mass fractions (0%, 2%, 4% and 6%) on the emulsion stability, emulsion gel properties and in vitro digestibility of chicken breast myofibrillar proteins (MP) were analyzed. Fourier transform infrared spectroscopy (FTIR) showed no covalent interaction between MP and pea RS3. The addition of pea RS3 significantly decreased the surface hydrophobicity (P < 0.05) while increasing the fluorescence intensity of MP, indicating enhanced protein-protein interactions. The addition of pea RS3 resulted in improved stability of MP emulsions, as manifested by higher absolute values of zeta potential, smaller droplet sizes and reduced creaming index. These changes promoted the formation of gel networks with improved texture and increased storage modulus (G’), gel strength and water holding capacity (WHC), especially at a pea RS3 concentration of 6%. The chemical force results showed that the addition of pea RS3 led to enhanced hydrophobic interaction and disulfide bonding between MP molecules. Low field-nuclear magnetic resonance (LF-NMR) confirmed that pea RS3 addition facilitated the migration of free water to immobilized water. Furthermore, the incorporation of pea RS3 caused a lower pepsin digestibility without changing the overall in vitro digestibility of MP gels. These results indicated that pea RS3 addition can contribute to the production of high-quality meat products with a low glycemic index without reducing protein digestibility.