Recently, compared to traditional food production systems, 3D food printing has gained a lot of interest because of the potential benefits of being able to customized food products fabrication in colour, shape, texture, flavor and even nutrition. Successful printing of food objects in 3D food printing is critical, and high accuracy and precision food printing technology is required to reproduce delicate and complex food 3D structures. In 3D food printing, the properties of food materials, such as rheological properties, chemical properties and thermal stability, are significant for the structure accuracy and precision of printed objects. In this study, we tried to present a 3D structure layering method for potato resistant starch using drop‐on‐demand (DOD) printing method (piezoelectric system type) that can express the fine structure of food by inkjet printing technology. Nanocrystals cellulose (CNC) and sodium alginate (AS) were used to form a food 3D structure, and 3D printing optimal ink formulation ratio of CNC and AS (CNC:AS=80:20) was selected through preliminary experiments. The purpose of this study was to determine the possibility of 3D printing and printability after comparing rheological properties of mixtures with and without annealing by varying the content of potato resistant starch (PRS) in the mixture of CNC and AS. 3D food structure with various combination of potato resistant starch (RS) to a mixture of CNC and AS was printed, and compared the rheological properties of the mixture that had not been temperature‐treated and the one that had been annealed. After that, the optimal material combination for precise 3D printing was explored together with the physical properties of the printed object. Support or Funding Information This research was supported in part by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (2018R1D1A1B07045349), the High Value‐added Food Technology Development Program, the Ministry of Agriculture, Food and Rural Affairs (MAFRA), Republic of Korea (118059‐2) and the Ewha Womans University Research Grant of 2019. Piezo‐electric based Ultraprecise/Ultratrace 3D Food Printing

The aim of this study was to develop and characterize an antibacterial fiber mat composed of chitosan, zein, and gelatin. The fiber mat was prepared using the adhesion between probes by a 3D printer, and Fourier transform infrared spectroscopy (FTIR), water contact angle measurement, scanning electron microscope (SEM) and mechanical tests were performed on this. The addition of chitosan was able to reduce the diameter of single fibers by reducing the viscosity, and the fiber mat showed a uniform texture and smooth surface in morphological properties. As a result, it showed hydrophobicity in surface chemical properties through molecular interaction between molecules and good flexibility and deformability in mechanical properties. In order to evaluate the antimicrobial activity of the fiber mat, the viable count method was performed. The results showed that zein/gelatin (1:1, w/w) fiber mats containing 1.5%, 3% and 4.5% chitosan were effective against both of Staphylococcus aureus and Escherichia coli as model as Gram‐positive and Gram‐negative bacteria, respectively. Furthermore, when zein/gelatin (1:1, w/w) containing no chitosan was set as a control, it showed an activity of 99% inhibition within 24 hours. Antibacterial fiber mats using protein‐based materials can be expected to be applied in food packaging and wound dressings through.

In the field of food processing, 3D food printing can be one of the foremost methods which allows to laminate various type of complex food structures. The technology makes it possible to manufacture food products with desired internal structures, tastes, flavors and nutrition and is attracting attention as an innovative way to customize food to meet each customer's needs. 3D printing can produce a wide range of foods with different textures and viscosities using the cartridge loaded with materials ranging from soft sauces to hard doughs. Additionally, for controlling the material while processing in the 3D printer, the food ink should be easily ejected through the nozzle, and pretreatment is required to homogenize and reduce the particle size. Since the ionic layer on the surface of the powder particles affects the bonding between the powders, zeta potential measured on the surface of these can be used as a standard for monitoring the organization of powdered materials in 3D printed substitute meat. In this study, various prototype of meat substitute was prepared using protein powder‐based materials with various processing parameters on the particle surface, and the texture was evaluated by comparing and analyzing the physical properties. Specifically, the particle surface state of the powder material was monitored by measuring various properties including the zeta potential, and the physico‐chemical and rheological properties of 3D printed meat substitute were analyzed to deduce the relationship for reaching the food processing aptitude.

In this study, we investigated the optimal conditions for 3D structure printing of alternative fats that have the textural properties of lard using beeswax (BW)-based oleogel by a statistical analysis. Products printed with over 15% BW oleogel at 50% and 75% infill level (IL) showed high printing accuracy with the lowest dimensional printing deviation for the designed model. The hardness, cohesion, and adhesion of printed samples were influenced by BW concentration and infill level. For multi-response optimization, fixed target values (hardness, adhesiveness, and cohesiveness) were applied with lard printed at 75% IL. The preparation parameters obtained as a result of multiple reaction prediction were 58.9% IL and 16.0% BW, and printing with this oleogel achieved fixed target values similar to those of lard. In conclusion, our study shows that 3D printing based on the BW oleogel system produces complex internal structures that allow adjustment of the textural properties of the printed samples, and BW oleogels could potentially serve as an excellent replacement for fat.

Inkjet printing technology has been applied to the fabrication of food products with high precision/resolution and minimal material waste. This technique has been applied only to materials with low viscosity because of mechanical limitation. And, it has been challengeable to build 3D structure of food with high resolution for high viscous food materials. In this study, using an ink‐jet‐type, drop‐on‐demand (DOD)‐based piezo‐electric jet printer, RS2 type resistant starch, which is known as “rigid and not easy to build 3D structure”, is laminated and structured to verify the possibility of 3D structuring of resistant starch. Raw potato starch (RPS) was utilized as the RS2‐type resistant starch material, and cellulose nanocrystals (CNC) and sodium alginate (AS) were used as the structural materials for RS2‐type resistant starch lamination. First, RPS (0%, 1%, 3%, and 5%) was added to the CNC and AS mixture to analyze rheological properties, 3D printing, precision, and physical properties. The mixed ink of CNC, AS and RPS will be named CAP. For rheological properties, a frequency sweep was performed within the range of 0.01 to 16 Hz. The CAP ink according to RPS content exhibited shear‐thinning behavior and was easily extruded from the nozzle during 3D printing. The value of G' indicated maintained shape of the structure in the range of 1133.51 to 1326.27 Pa. During 3D printing with the same CAP head parameters, the pressure range of CAP ink extrusion differed depending on RPS content. The CAP with 5% RPS was in contact with the nozzle during printing due to the high pressure. In piezo‐electric jet printing, the precision of the RS2‐type resistant starch 3D structure was affected by pressure. Hardness increased as RPS content increased. This study showed that 3D lamination of RS2‐type resistant starch material was possible up to 3% RPS, demonstrating the possibility of developing 3D resistant starch food products using an inkjet piezo‐electric jet printer.