Microwave-induced spontaneous deformation of purple potato puree and oleogel in 4D printing

Plant-Based Meat Analogues and Consumer Interest in 3D-Printed Products: A Mini-Review

The markets for plant-based meat analogues (PBMAs) are growing worldwide, showing the increasing consumer demand for and acceptance of these new products. Three-dimensional (3D) food printing is a new technology with huge potential for printing products customised to suit consumers' wants and needs. There is a broad acceptance from consumers regarding the safety and desirability of consuming food products that are produced using 3D printing. As this is a new technology, consumers must be provided with relevant information from a trusted source, with further research needing to be conducted within the context of the identified market and culture. By embracing the strength of customisation of 3D printing and coupling this with the global demand for plant-based products, 3D printed PBMAs could be a future challenger to the currently popular production method of extrusion. Therefore, this article reviews consumer interests in PBMAs and summarises opportunities for using 3D printing technology to produce plant-based meat analogues.

The color/shape/flavor of yam gel with double emulsified microcapsules changed synchronously in 4D printing induced by microwave

The feasibility of 3D printing the color, aroma and shape changes of yam gel with microwave heating as stimulus and soybean protein isolate-chitosan-maltodextrin complex coacervated microcapsules rich in water-soluble betacyanin and rose essence as stimulus-response materials was discussed. The morphology of microcapsules presented irregular spherical structure, and the surface was relatively smooth and slightly concave. Microwave heating led to the gradual destruction of microcapsules in yam gel, releasing internal pigments and essence, and enhancing the redness and flavor of printed samples. The release of the water phase and oil phase of the microcapsules and the hot-spot expansion effect of the models made the 3D printed bird models bend and deform, realizing the deformation effect of "spreading of wings", which realized a three-response synchronous change in color, shape, and flavor of the printed samples within 45 s. In this study, a variety of 4D printed foods with synchronous changes in sensory characteristics were created, which increased sensory enjoyment on the basis of ensuring the nutritional needs of food.

Pleurotus ostreatus is a promising candidate of an edible 3D printing ink: Investigation of printability and characterization

The 3D printing (3DP) technology shows great potential in the food industry, but the development of edible ink is currently insufficient. Pleurotus ostreatus (P. ostreatus) emerges as a novel promising candidate. In this study, a mixed ink was obtained by incorporating butter into P. ostreatus. The effects of different ratios of P. ostreatus and butter, as well as the influence of ink steaming were investigated on 3D printed products. The results indicated that all inks of the P. ostreatus system exhibited positive shear-thinning behavior, and the system maintained stable intermolecular hydrogen bonding when P. ostreatus powder concentration was 40 % (w/v). Furthermore, the L* value of the system was elevated for butter adding. The system with steaming exhibited superior stabilized molecular structure compared to the native system, particularly with a steaming duration of 5 min, showcasing its outstanding supporting capacity. This study suggests that P. ostreatus is a promising candidate in 3DP for the development of an edible ink that promotes innovation and nutritional food.

Encapsulation of lutein in gelatin type A/B-chitosan systems via tunable chains and bonds from tweens: Thermal stability, rheologic property and food 2D/3D printability

Lutein could be stabilized in gelatin type A/B-chitosan systems by different polyoxyethylene sorbitan fatty acid esters (tweens) via tunable chains and bonds, and the homogeneous system held potential in food 2D/3D printing. During encapsulation of lutein in gelatin-chitosan matrix complexes, tween 40, tween 60 and tween 80 assisted in the excellent centrifugation stability, freeze-thaw stability, chemical stability as well as thermal stability. The tweens contained systems also possessed excellent rheological properties, including shearing thinning property, self-supporting characteristics, and favorable thixotropy. Especially, tween 80 performed well in facilitating the stability and rheological properties of systems with uniform micromorphology due to its long alkyl chains and carbon-carbon double bonds (two sp2 hybridized C-atoms) (from FTIR, XRD, SEM, etc.); and gelatin type B illustrated higher protection effects on lutein because of its strong electrostatic interaction with chitosan. The optimal systems could work as edible ink for 2D/3D printing on food with great UV-irradiation stability and high definition. Surimi could be modified by the optimal complex and possessed excellent shear-thinning property, proper yield stress, low dependence on frequency and stable structure, which was successfully applied for innovative 3D printing with sophisticated shapes. The practical food 2D/3D printing (like bread and surimi) demonstrated high potential in food creation and food innovation.

Recent insights on advancements and substantial transformations in food printing technology from 3 to 7D

Food printing using 3D, 4D, and 5D printing processes has received a lot of interest as a result of rising living standards and increased customer desire for new foods. In the food industry, 3D as well as 4D printing are extremely effective methods for additive manufacturing. The 3D printing technology produces flat objects with a variety of mechanical strengths. The strength of the object depends on the type of material used and the printing process. Printing structures with the most complex geometric, such as curved surfaces, necessitates the usage of supplementary material. The 4D printing procedure necessitates additional stimuli in order to adjust the aspect of the generated geometry. These obstacles can be addressed by employing 5D printing techniques, which prints the product in three motions and two rotational axes without the use of additional support material. These emerging innovations are likely to result in substantial advancements in all industries, including the manufacturing of high-quality food products. Food printing technology can be used to create long shelf-life products by printing food with protective coatings that prevent oxidation and degradation. Foods can also be printed in specific shapes or sizes to reduce surface area exposed to air. 6D printed objects can be created as a result of 5D printing because it is regarded as a by-product of 5D printing technology. 6D printing can save time and money by using the right processing parameters to create strong materials that are more sensitive to stimuli. 7D printing can enable more efficient production processes, reduce costs, and enable the development of products that are more complex and intricate than what is achievable with traditional manufacturing methods. The revolutionary change brought by food printing technologies in the field of applications, research and development, processing, advantages in food industry have been discussed in this paper.

Double-nozzle 3D-printed bean paste buns: Effect of filling ratio and microwave heating time

With the aggravation of the global aging process, more and more elderly people are facing the problem of dysphagia. The advantages of three-dimensional (3D) printing in making chewy food are increasingly prominent. In this study, the two-nozzle 3D printer was used to explore the effects of different proportions of buckwheat flour, printing filling ratio, microwave power, and time on the quality of bean-paste buns. The results showed that the bean paste filling containing 6% buckwheat flour had the best antioxidant and sensory properties. When the filling ratio was 21.6%, the microwave power was 560 W, and the time was 4 min, the obtained sample was the most satisfactory. Compared with the microwave-treated and steamed traditional samples, the chewiness of the samples was reduced by 52.43% and 15.14%, respectively, and the final product was easier to chew and swallow.

Four-Dimensional (4D) Printing of Dynamic Foods-Definitions, Considerations, and Current Scientific Status

Since its conception, the application of 3D printing in the structuring of food materials has been focused on the processing of novel material formulations and customized textures for innovative food applications, such as personalized nutrition and full sensory design. The continuous evolution of the used methods, approaches, and materials has created a solid foundation for technology to process dynamic food structures. Four-dimensional food printing is an extension of 3D printing where food structures are designed and printed to perform time-dependent changes activated by internal or external stimuli. In 4D food printing, structures are engineered through material tailoring and custom designs to achieve a transformation from one configuration to another. Different engineered 4D behaviors include stimulated color change, shape morphing, and biological growth. As 4D food printing is considered an emerging application, imperatively, this article proposes new considerations and definitions in 4D food printing. Moreover, this article presents an overview of 4D food printing within the current scientific progress, status, and approaches.

3D printing technology for prepared dishes: printing characteristics, applications, challenges and prospects

Prepared dishes are popular convenience foods that meet the needs of consumers who pursue delicious tastes while saving time and effort. As a new technology, food 3D printing (also known as food additive manufacturing technology) has great advantage in the production of personalized food. Applying food 3D printing technology in the production of prepared dishes provides the solution to microbial contamination, poor nutritional quality and product standardization. This review summarizes the problems faced by the prepared dishes industry in traditional food processing, and introduces the characteristics of prepared dishes and 3D printing technology. Food additives are suitable for 3D prepared dishes and novel 3D printing technologies are also included in this review. In addition, the challenges and possible solutions of the application of food 3D printing technology in the field of prepared dishes are summarized and explored. Food additives with advantages in heat stability, low temperature protection and bacteriostasis help to accelerate the application of 3D printing in prepared dishes industry. The combination of 3D printing technology with heat-assisted sources (microwave, laser) and non-heat-assisted sources (electrolysis, ultrasound) provides the possibility for the development of customized prepared dishes in the future, and also promotes more 3D food printing technologies for commercial use. It is noteworthy that these technologies are still at research stage, and there are challenges for the formulation design, the stability of printed ink storage, as well as implementation of customized nutrition for the elderly and children.

Microwave-Induced Rapid Shape Change of 4D Printed Vegetable-Based Food

Microwave heating acts as an environmental stimulus factor to induce rapid shape changes in 4D-printed stereoscopic models over time. The influence of microwave power and model structure on the shape change behavior was explored, and the applicability of the deformed method to other vegetable-based gels was verified. The results described that the G', G″, η, and proportion of bound water of yam gels increased with the increase in yam powder content, and the yam gel with 40% content had the best printing effect. The IR thermal maps showed the microwaves first gathered in the designed gully region caused the swelling phenomenon, which induced the printed sample to undergo a bird-inspired "spreading of wings" process within 30 s. Increasing the microwave power and microwave heating time were able to increase the bending angles and dehydration rates of the printed samples, thus improving the deformed degree and deformed speed. Different model base thicknesses (4, 6, 8, and 10 mm) also had significant effects on the shape change of the printed structures. The efficiency of the shape changes of 4D-printed structures under microwave induction can be judged by studying the dielectric properties of the materials. In addition, the deformed behaviors of other vegetable gels (pumpkin and spinach) verified the applicability of the 4D deformed method. This study aimed to create 4D-printed food with personalized and rapid shape change behavior, providing a basis for the application scenarios of 4D-printed food.

Progress in Extrusion-Based Food Printing Technology for Enhanced Printability and Printing Efficiency of Typical Personalized Foods: A Review

Three-dimensional printing technology enables the personalization and on-demand production of edible products of individual specifications. Four-dimensional printing technology expands the application scope of 3D printing technology, which controllably changes the quality attributes of 3D printing products over time. The concept of 5D/6D printing technology is also gradually developing in the food field. However, the functional value of food printing technology remains largely unrealized on a commercial scale due to limitations of printability and printing efficiency. This review focuses on recent developments in breaking through these barriers. The key factors and improvement methods ranging from ink properties and printer design required for successful printing of personalized foods (including easy-to-swallow foods, specially shaped foods, and foods with controlled release of functional ingredients) are identified and discussed. Novel evaluation methods for printability and printing precision are outlined. Furthermore, the design of printing equipment to increase printing efficiency is discussed along with some suggestions for cost-effective commercial printing.

Advances in 3D printing of food and nutritional products

The main advantage of both 3D printing (3DP) and 3D food printing (3DFP) over other technologies is the enormous capacity of both techniques for customization. Its use makes it possible to obtain products without planning and implementing a complex and costly manufacturing process. This makes 3DFP a technology of choice for the preparation of food products that meet specific needs, such as controlled nutritional or rheological properties. However, further technological developments are still needed before 3DFP can be considered fully useful for innovative and demanding applications. If both preparation and post-processing of materials based on 3D printing are optimized, aiming to reduce production time and/or complication for non-expert users, this would open a whole new range of possibilities. It is in this sense that the development of advanced 3DFP systems becomes a must. This chapter reviews current advances in extrusion-based 3D food printing systems, with in situ gelation and mixing as key aspects to better exploit the potential of 3DFP. On one hand, 3DFP systems based on in situ gelation (G3DFP) provide greater control over the final properties of the printed products, as the selection of adequate printing parameters gives the possibility of influencing the gelation process. On the other hand, mixing is indispensable for true 3DFP automation, so that the formulations do not have to be prepared by the user. Different innovative 3DFP systems based on gelling and/or mixing are presented in this chapter. Finally, the status and future of extrusion-based 3DFP, and its application in the production of customized foods for specific needs, are also overviewed.

Progress in 4D/5D/6D printing of foods: applications and R&D opportunities

4D printing is a result of 3D printing of smart materials which respond to diverse stimuli to produce novel products. 4D printing has been applied successfully to many fields, e.g., engineering, medical devices, computer components, food processing, etc. The last two years have seen a significant increase in studies on 4D as well as 5D and 6D food printing. This paper reviews and summarizes current applications, benefits, limitations, and challenges of 4D food printing. In addition, the principles, current, and potential applications of the latest additive manufacturing technologies (5D and 6D printing) are reviewed and discussed. Presently, 4D food printing applications have mainly focused on achieving desirable color, shape, flavor, and nutritional properties of 3D printed materials. Moreover, it is noted that 5D and 6D printing can in principle print very complex structures with improved strength and less material than do 3D and 4D printing. In future, these new technologies are expected to result in significant innovations in all fields, including the production of high quality food products which cannot be produced with current processing technologies. The objective of this review is to identify industrial potential of 4D printing and for further innovation utilizing 5D and 6D printing.

Preparation of Smart Materials by Additive Manufacturing Technologies: A Review

Over the last few decades, advanced manufacturing and additive printing technologies have made incredible inroads into the fields of engineering, transportation, and healthcare. Among additive manufacturing technologies, 3D printing is gradually emerging as a powerful technique owing to a combination of attractive features, such as fast prototyping, fabrication of complex designs/structures, minimization of waste generation, and easy mass customization. Of late, 4D printing has also been initiated, which is the sophisticated version of the 3D printing. It has an extra advantageous feature: retaining shape memory and being able to provide instructions to the printed parts on how to move or adapt under some environmental conditions, such as, water, wind, light, temperature, or other environmental stimuli. This advanced printing utilizes the response of smart manufactured materials, which offer the capability of changing shapes postproduction over application of any forms of energy. The potential application of 4D printing in the biomedical field is huge. Here, the technology could be applied to tissue engineering, medicine, and configuration of smart biomedical devices. Various characteristics of next generation additive printings, namely 3D and 4D printings, and their use in enhancing the manufacturing domain, their development, and some of the applications have been discussed. Special materials with piezoelectric properties and shape-changing characteristics have also been discussed in comparison with conventional material options for additive printing.