Classification of the printability of selected food for 3D printing: Development of an assessment method using hydrocolloids as reference material

Effect of deacetylated konjac glucomannan on the 3D printing properties of minced pork

BACKGROUND

The influences of deacetylated konjac glucomannan (DKGM) at different condition levels (0.0%, 0.5%, 1.0%, 1.5%, 2.0%) on the 3D printing feasibility, printing properties, and the final gel characteristics of minced pork were investigated.

RESULTS

As the DKGM content increased, the printing accuracy and stability initially increased and then declined, and the printing stability and accuracy increased to their highest levels (98.16% and 98.85%) with a 1.5% addition of DKGM. Furthermore, the addition of DKGM significantly enhanced the texture of 3D-printed meat after heat treatments. When the DKGM content reached 1.5%, the hardness and springiness were 1.19 and 1.06 times higher than those of the control group. The results of low-field nuclear magnetic resonance and Raman spectra revealed that DKGM enhanced the amount of bound water in 3D-printed meat and encouraged changes in protein structure. After the addition of DKGM at 1.5%, the contents of bound water and β-sheets were 7.67% and 12.89% higher than those of the control group, respectively, facilitating the development of a better gel network of minced meat during heating.

CONCLUSION

The results indicate that a concentration of 1.5% DKGM is the ideal setting for obtaining the desired rheological properties and textural characteristics (printability) of 3D-printed minced meat products compared to other samples. In addition, the results showed that the addition of DKGM at 1.5% promotes the transition from α-helix to β-folding of proteins during heating, which facilitates the formation of gels. The results of the study contribute to the application potential of minced meat in the field of 3D food printing. © 2024 Society of Chemical Industry.

3D printing: trends and approaches toward achieving long-term sustainability in the food industry

Global food security has recently been under serious threat from the rapid rise in the world's population, the problems brought on by climate change, and the appearance of new pandemics. As a result, the need for novel and innovative solutions to solve the existing problems and improve food sustainability has become crucial. 3D printing is expected to play a significant role in providing tangible contributions to the food industry in achieving sustainable development goals. The 3D food printing holds the potential to produce highly customized food in terms of shape, texture, flavor, structure and nutritional value and enable us to create new unique formulations and edible alternatives. The problem of whether the cost of the printed meal and 3D printing itself can be sustainably produced is becoming more and more important due to global concerns. This review intends to provide a comprehensive overview of 3D printed foods with an overview of the current printing methodologies, illustrating the technology's influencing factors, and its applications in personalized nutrition, packaging, value addition, and valorization aspects to fully integrate sustainability concerns thus exploring the potential of 3D food printing.

Effect of l-cysteine on functional properties and fibrous structure formation of 3D-printed meat analogs from plant-based proteins

The development of three-dimensional (3D) printed meat analogs with fiber, texture, and sensory resembling meat remains challenging. This study investigated the effect of l-cysteine on functionality enhancement and fibrous structure formation in mixtures of mung bean protein isolate (MBPI) and wheat gluten (WG) for meat analog production. 3D printing was used to construct fibrous filaments. Raw MBPI-WG mixtures decreased rheological properties when increasing l-cysteine contents (0.0%-0.6%), promoting ink extrudability. The cys-0.4% ink exhibited the highest printing resolution and structural stability, correlated with its higher mechanical strength and increased disulfide cross-links. After cooking, the cys-0.4% sample showed a pronounced fibrousness in agreement with its microstructure image. This meat analog displayed a muscle-meat-like structure, improved texture, and reduced beany odor and bitter taste. Excessive cysteine contents (0.5%-0.6%) negatively affected the functionality of meat analogs. This study provides guidance for optimizing the amount of l-cysteine in meat analogs to improve product quality.

3D Printing of Materials and Printing Parameters with Animal Resources: A Review

3D printing technology enables the production of creative and personalized food products that meet consumer needs, such as an attractive visual appearance, fortification of specific nutrients, and modified textures. To popularize and diversify 3D-printed foods, an evaluation of the printing feasibility of various food pastes, including materials that cannot be printed natively, is necessary. Most animal resources, such as meat, milk, and eggs, are not inherently printable; therefore, the rheological properties governing printability should be improved through pre-/post-processing or adding appropriate additives. This review provides the latest progress in extrusion-based 3D printing of animal resource-based inks. In addition, this review discusses the effects of ink composition, printing conditions, and post-processing on the printing performance and characteristics of printed constructs. Further research is required to enhance the sensory quality and nutritional and textural properties of animal resource-based printed foods.

Exploring the potential of bacterial cellulose paste as a fat replacer for low-fat plant-based hamburger patties

Plant-based hamburger patties (PHPs) with reduced fat content made using fat replacers will meet the consumption goals of individuals who consume meat alternative products for health. In this study, we developed a dual-alternative food model by analysing the applicability of bacterial cellulose paste (BCP) as a fat replacer and supplementing it in PHPs. BCPs were prepared with solid contents of (w/w; 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%) and compared and analyzed with three types of conventional vegetable [coconut oil, margarine, and shortening (SH)] and animal fats (beef tallow, butter, and lard) for various characteristics (appearance, dimensional stability, hardness level, and rheological properties). According to the results, BCP with a solid content of 3.0% (w/w) had the most similar characteristics to SH. Therefore, using SH as a control fat, PHPs in which 0%, 25%, 50%, 75%, and 100% (w/w) SH were replaced by 3.0% (w/w) BCP were prepared. Analysis of the appearance, instrumental color, diameter reduction, thickness, cooking loss, and texture profile of the PHPs, confirmed that replacement of 25%-50% (w/w) SH with 3.0% (w/w) BCP in the preparation of PHP resulted in i) redder color, ii) better dimensional stability, iii) lower cooking loss, and iv) higher chewiness of the final products. The results of the sensory evaluation showed that the PHPs, with 25%-50% (w/w) SH replaced with 3.0% (w/w) BCP, exhibited no significant differences (p < 0.05) in overall preference scores compared to the full-SH sample. In conclusion, this study demonstrated the potential of BCP as a fat substitute for the production of PHPs.

Elaboration of dimensional quality in 3D-printed food: Key factors in process steps

Three-dimensional (3D) printing has been applied to produce food products with intricate and fancy shapes. Dimensional quality, such as dimensional stability, surface smoothness, shape fidelity, and resolution, are essential for the attractive appearance of 3D-printed food. Various methods have been extensively studied and proposed to control the dimensional quality of printed foods, but few papers focused on comprehensively and deeply summarizing the key factors of the dimensional quality of printed products at each stage-before, during, and after printing-of the 3D printing process. Therefore, the effects of pretreatment, printing parameters and rheological properties, and cooking and storage on the dimensional quality of the printed foods are summarized, and solutions are also provided for improving the dimensional quality of the printed products at each step. Before printing, incorporating additives or applying physical, chemical, or biological pretreatments can improve the dimensional quality of carbohydrate-based, protein-based, or lipid-based printed food. During printing, controlling the printing parameters and modifying the rheological properties of inks can affect the shape of printed products. Furthermore, post-processing is essential for some printed foods. After printing, changing formulations, incorporating additives, and selecting post-processing methods and conditions may help achieve the desired shape of 3D-printed or 4D-printed products during cooking. Additives help in the storage stability of printed food. Finally, various opportunities have been proposed to regulate the dimensional properties of 3D-printed structures. This review provides detailed guidelines for researchers and users of 3D printers to produce various printed foods with the desired shapes and appearances.

Application of xanthan and locust bean gum mix or sorbitol in the jelly formulation to improved jelly 3D printing using a fused deposition modeling printer

This study examined the impacts of applying a xanthan and locust bean gum mix or sorbitol to a jelly formulation on the rheological parameters necessary for 3D printing a jelly applying the fused deposition modeling method. A jelly formulation was fortified with a gum mix (xanthan gum:locust bean gum = 0.625:0.375) at 1% (w/w), or added with sorbitol instead of sugar. Both treatments increased the values of storage modulus and yield stress, related to fidelity and shape retention, and adding the gum mix, in particular, increased the gel strength. Applying these treatments to the formulation that lacks the rheological parameters and gel strength required for 3D printing changed those values in a direction fulfilling the material requirements. This research confirmed that the application of xanthan and locust bean gum mix or sorbitol could adjust the properties of materials used in 3D printing for improved printability.

Three-dimensional food printing: its readiness for a food and nutrition insecure world

Three-dimensional (3D) food printing is a rapidly emerging technology offering unprecedented potential for customised food design and personalised nutrition. Here, we evaluate the technological advances in extrusion-based 3D food printing and its possibilities to promote healthy and sustainable eating. We consider the challenges in implementing the technology in real-world applications. We propose viable applications for 3D food printing in health care, health promotion and food waste upcycling. Finally, we outline future work on 3D food printing in food safety, acceptability and economics, ethics and regulations.

3D printed meat and the fundamental aspects affecting printability

Three-dimensional (3D) printing, one of the forms of additive manufacturing, has become a popular trend worldwide with a wide range of applications including food. The technology is adaptable and meets foods nutritional and sensory needs allowing meat processing to reach a sustainable level, technology addressing the food requirement of the ever-increasing population and the fast-paced lifestyle by reducing food preparation time. By minimizing food waste and the strain on animal resources, technology can help to create a more sustainable economy and environment. This review article discusses the 3D printing process and various 3D printing techniques used for food printing, such as laser powder bed fusion, inkjet food printing, and binder jetting, a suitable 3D technique used for meat printing, such as extrusion-based bioprinting. Moreover, we discuss properties that affect the printability of meat and its products with their applications in the meat industry, 3D printing market potential challenges, and future trends.

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.

Viability Study on the Use of Three Different Gels for 3D Food Printing

Three-dimensional food printing is one of the modern techniques for food customization. The difficulty of this technique lies in the formulation of new matrices. These new formulations must have good extrusion characteristics and, at the same time, maintain the structure once printed. These qualities are related to textural and rheological properties. Printability studies are those whose objective is to know the above properties. Some authors have correlated printability with rheological and physicochemical parameters. The aim of this study was to characterize three gels to test prediction models and to determine the most important rheological and textural parameters (G', G″, Tanδ, maxF, average) in printability. The formulations studied were bovine gelatin (4%) with kappa-carrageenan (0.5%) (Gb + K), porcine gelatin (5%) plus iota-carrageenan (2%) (Gp + I), and methylcellulose (4%) (MC). The samples were characterized by an oscillatory test for the rheological properties and an extrusion test for the textural properties. In addition, the density was obtained to apply the predictive models and correlate the rheological and textural parameters to determine their influence. Gp + I and Gb + K showed higher values of maximum force in the extrusion test than MC, but MC had less deviation in the mean force during the test. All the samples showed a predominantly elastic behavior and damping factor (Tanδ) between 0.14 (Gb + K) and 0.37 (MC). It was observed that the tangent of the phase angle (Tanδ) had a large positive influence on the maximum and average force studied in the extrusion tests. The sample results did not match 100% with the predictions made from the models. It was possible to print samples that were higher in height without obtaining deformations over time of more than 5%. Further work is needed to optimize models and parameters for more accurate prediction.

Impact of Apricot Pulp Concentration on Cylindrical Gel 3D Printing

The process of 3D food printing is a rapidly growing field that involves the use of specialized 3D printers to produce food items with complex shapes and textures. This technology allows the creation of customized, nutritionally balanced meals on demand. The objective of this study was to evaluate the effect of apricot pulp content on printability. Additionally, the degradation of bioactive compounds of gels before and after printing was evaluated to analyze the effect of the process. For this proposal, physicochemical properties, extrudability, rheology, image analysis, Texture Profile Analysis (TPA), and bioactive compounds content were evaluated. The rheological parameters lead to higher mechanical strength and, thus, a decrease in elastic behavior before and after 3D printing as the pulp content increases. An increase in strength was observed when the pulp content increased; thus, sample gels with 70% apricot pulp were more rigid and presented better buildability (were more stable in their dimensions). On the other hand, a significant (p < 0.05) degradation of total carotenoid content after printing was observed in all samples. From the results obtained, it can be said that the gel with 70% apricot pulp food ink was the best sample in terms of printability and stability.

Integrated design of micro-fibrous food with multi-materials fabricated by uniaxial 3D printing

Owing to the interest in sustainable foods, a new approach known as 3D food printing is being employed to make fibrous foods for meat and fish substitutes. In this study, we developed a filament structure with a multi-material ink comprising fish surimi-based ink (SI) and plant-based ink (PI), using single-nozzle printing and steaming. PI and an SI + PI mix collapsed after printing owing to their low shear modulus, although both PI and SI showed gel-like rheological behaviors. However, unlike the control, the objects printed with two and four columns per filament remained stable and fiberized after steaming. Each SI and PI sample gelatinized irreversibly at approximately 50 °C. The different rheological values of these inks after cooling resulted in relatively strong (PI) and weak (SI) fibers, which constructed a filament matrix. A cutting test demonstrated that the transverse strength of the fibrous structure of the printed objects was higher than the longitudinal strength, in contrast to that of the control. The degree of texturization increased with the fiber thickness based on the column number or nozzle size. Thus, we successfully designed a fibrous system using printing and post-processing and substantially broadened the application opportunities for creating fibril matrices for sustainable food analogs.

Meat substitutes: Resource demands and environmental footprints

The modern food system is characterized with high environmental impact, which is in many cases associated with increased rates of animal production and overconsumption. The adoption of alternatives to meat proteins (insects, plants, mycoprotein, microalgae, cultured meat, etc.) might potentially influence the environmental impact and human health in a positive or negative way but could also trigger indirect impacts with higher consumption rates. Current review provides a condensed analysis on potential environmental impacts, resource consumption rates and unintended trade-offs associated with integration of alternative proteins in complex global food system in the form of meat substitutes. We focus on emissions of greenhouse gases, land use, non-renewable energy use and water footprint highlighted for both ingredients used for meat substitutes and ready products. The benefits and limitations of meat substitution are highlighted in relation to a weight and protein content. The analysis of the recent research literature allowed us to define issues, that require the attention of future studies.

3D printing based on meat materials: Challenges and opportunities

Three-dimensional (3D) printing, as an emerging technology, is driving great progress in the food industry. In the meat field, 3D printing is expected to replace the traditional food industry and solve the problems of raw material waste and food contamination. Nevertheless, the application of 3D printing in meat still faces many challenges. The rheological properties of the ink, such as shear thinning behavior, viscosity, and yield stress, are critical in determining whether it can be printed smoothly and ensuring the quality of the product. Meat materials are complex multi-phase colloidal systems with unique fibrous structures that cannot be printed directly, and improving the printability of meat colloids mainly limits meat printing. The complexity of meat colloidal systems determines the different heat requirements. In addition, at this stage, the functionality of the printer and the formulation of a single nutritional and organoleptic properties limit the implementation and application of 3D printing. Moreover, the development of cultured meat, the full application of by-products, and the emergence of new technologies provides opportunities for the application of 3D printing in the meat industry. This review highlights the current challenges and opportunities for the application of 3D printing in meat to provide new ideas for the development of 3D printing.

3D Printed gelatin film with Garcinia atroviridis extract

Active packaging, such as edible film with antibacterial properties, can help extend the shelf life of food. The research aimed to develop a 3D printed gelatin edible film by using glycerol and Garcinia atroviridis extract (GAE). Mechanical properties of gelatin gel, physical, mechanical, and antimicrobial properties of edible film with glycerol and GAE were determined. Water solubility, total colour difference, and elongation of break of gelatin edible film increased as glycerol concentration increased (0-25% w/w), whereas tensile strength and Young's modulus value decreased from 26.5 to 4.64 MPa and 3.04 to 0.13 MPa, respectively. On the other hand, increasing GAE from 1 to 4% (w/w) increases elongation at break from 40.83 to 98.27%, while decreasing edible film tensile strength and gelatin gel hardness value from 8.94 to 6.21 MPa and 1848.67 to 999.67 g, respectively. Using 20% (w/w) glycerol and 4% (w/w) GAE, the best 3D printed film with low tensile strength (6.21 MPa), high elongation at break (98.27%), and antibacterial activity against S. aureus with 7.23 mm zone of inhibition was developed. It seems to have a great potentiality as an active packaging material for 3D printed gelatin edible film.

Characterization of rice flour and pastes with different sweeteners for extrusion-based 3D food printing

This work aims at investigating the impact of commonly used sweeteners-sugar and jaggery on 3D printability of rice flour (RF) paste. The physicochemical characteristics of rice flour suitable for 3D food printing have been investigated. Three mixes, rice flour with water (M₁ : RF-50.86%, water-49.14%), rice flour with sugar and water (M₂ : RF-36.75%, sugar-14.10%, water-49.14%) and rice flour with jaggery and water (M₃ : RF-36.75%, jaggery-14.10%, water-49.14%) were compared on 3D printability based on visual inspection and properties supporting 3D printability and shape retention. The effect of the three mixes was characterized on color, rheological, thixotropic, and handling properties. Out of the three mixes, M₃ is found to have the best printability characteristics with shear thinning behavior, yield stress of 157 Pa, flow stress of 121 Pa, and extrusion force of 6.62 kg.

Three-Dimensional Printing Properties of Polysaccharide Hydrocolloids–Unrinsed Sturgeon Surimi Complex Hydrogels

Herein, the microstructure and mechanical properties of hydrogels consisting of unrinsed sturgeon surimi (URSS) and plant-derived polysaccharides such as κ-carrageenan (KC), konjac gum (KG), xanthan gum (XG), guar gum (GG) and sodium alginate (SA), were studied by texture analysis, rheological measurement and scanning electron microscopy (SEM). Rheological results showed that the apparent viscosity, storage modulus (G′) and loss modulus (G″) of URSS increased by addition of KC, KG, GG and SA. The gel strength of resultant surimi products fabricated with KG/URSS mixture was significantly higher than that of other groups. KG could significantly improve the hardness (44.14 ± 1.14 N), chewiness (160.34 ± 8.33 mJ) and cohesiveness (0.56 ± 0.02) of the unrinsed surimi gel. Adding SA and KC had no significant effect on the textural characteristics of printed gels. However, an apparent decrease in the relevant mechanical properties of printed hydrogels was observed when XG and GG were added into surimi. SEM indicated that the incorporation of KG and KC could further integrate the gel structure of URSS as compared to hindering the cross-linking of surimi protein by XG and GG, which were in accordance with gel strength and water-holding capacity. These results provided useful information to regulate the 3D printing performance in functionalized surimi-based material.

Linking Processing Parameters and Rheology to Optimize Additive Manufacturing of k-Carrageenan Gel Systems

Additive manufacturing—in particular, three-dimensional (3D) printing—has been introduced since the late 1980s, offering a novel paradigm for engineering design and manufacturing, as it allows the fabrication of very complex structures. Additive manufacturing of hydrogels is a very popular method to produce scaffolds to be used in tissue engineering and other biomedical applications, as well as in other advanced technological areas. When printing a thermoreversible physical hydrogel, a subtle balance between thermal and rheological parameters exists. The characteristic times of the sol–gel transition, regulated by a well-defined thermal history, must be optimized with respect to the characteristic processing times. In this work, we use this thermo-rheological approach to the additive manufacturing of a physical hydrogel. A low-cost desktop 3D printer for thermoplastic polymers was suitably modified to print a 1.5 wt% solution of k-carrageenan. The thermal behavior of the printer was determined by performing experimental measurements of the temperature–time evolution during the different processing steps, from solution loading, to the extrusion of the incoming gel, to the final solidification stage. In parallel, linear viscoelastic oscillatory shear measurements were performed in a rotational rheometer under thermal histories as close as possible to those previously measured in the printing process. The comparison between the rheological results and the quality of printing under different thermal histories is presented and discussed, highlighting the main relations between rheological and processing behavior, which are helpful in the assessment and optimization of the printing conditions.

The future of 3D food printing: Opportunities for space applications

Over the past decade or so, there have been major advances in the development of 3D printing technology to create innovative food products, including for printing foods in homes, restaurants, schools, hospitals, and even space flight missions. 3D food printing has the potential to customize foods for individuals based on their personal preferences for specific visual, textural, mouthfeel, flavor, or nutritional attributes. Material extrusion is the most common process currently used to 3D print foods, which is based on forcing a fluid or semi-solid food "ink" through a nozzle and then solidifying it. This type of 3D printing application for space missions is particularly promising because a wide range of foods can be produced from a limited number of food inks in a confined area. This is especially important for extended space missions because astronauts desire and require a variety of foods, but space and resources are minimal. This review highlights the potential applications of 3D printing for creating custom-made foods in space and the challenges that need to be addressed.

Application of 3D Printing in the Design of Functional Gluten-Free Dough

The design of functional foods through 3D printing is proposed here as one of the most appropriate technologies to provide closer food personalization for the population. However, it is essential to study the properties of the biomaterials intended to be printed. This work will evaluate the incorporation of rosehip as a functional ingredient in a gluten-free dough. Three types of dough (control, rosehip, and encapsulated rosehip) were printed in a rectangular figure of dimensions 7 cm long, 2 cm wide, and 1, 2, and 3 cm high. Changes in printed figures before and after baking were evaluated by image analysis. Physicochemical properties, total phenols (TP), antioxidant capacity (AC), and total carotenoids (TC) were determined both in the pre-printed doughs and in the printed and baked samples. The bread enriched with rosehips presented more orange colors in dough and crumbs. They were also more acidic than control, probably due to the ascorbic acid content of rosehip. The addition of rosehip generally makes the product more resistant to breakage, which could be due to the fiber content of the rosehip. It was observed that the incorporation of rosehip notably improved the functional properties of the bread.

Material requirements for printing cookie dough using a fused deposition modeling 3D printer

This study examined the requirements for using flour-based formulations in fused deposition modeling (FDM) of cone-shaped cookie dough. By considering the requirements of fidelity, shape retention, and extrudability, the rheological and mechanical parameters, which resulted in high printability (93.88‒96.49%) and dimensional stability (96.36‒97.15%), for formulations containing soft wheat flour, granulated sugar, water, and olive oil were determined to be: storage modulus (G') of 7165‒12,590 Pa, loss modulus (G″) of 4161‒8297 Pa, shear modulus of 6613‒12,804 Pa, yield stress (τ₀) of 50.22‒72.80 Pa, phase angle of 30.28‒33.52°, apparent viscosity of 181.25‒230.20 Pa·s, and hardness of 0.65-0.91 N. When olive oil and water were replaced with butter and egg, the formulations demonstrated higher values of G', G″, shear modulus, τ₀, and hardness; a smaller phase angle; and a wider range of apparent viscosity. These results provide quantitative information for developing cookie dough formulations suitable for 3D printing by FDM.

Towards the Development of 3D-Printed Food: A Rheological and Mechanical Approach

Additive manufacturing, or 3D printing, has raised interest in many areas, such as the food industry. In food, 3D printing can be used to personalize nutrition and customize the sensorial characteristics of the final product. The rheological properties of the material are the main parameters that impact the 3D-printing process and are crucial to assuring the printability of formulations, although a clear relationship between these properties and printability has not been studied in depth. In addition, an understanding of the mechanical properties of 3D-printed food is crucial for consumer satisfaction, as they are related to the texture of food products. In 3D-printing technologies, each manufacturing parameter has an impact on the resulting mechanical properties; therefore, a thorough characterization of these parameters is necessary prior to the consumption of any 3D-printed food. This review focuses on the rheological and mechanical properties of printed food materials by exploring cutting-edge research working towards developing printed food for personalized nutrition.

Faba Bean Fractions for 3D Printing of Protein-, Starch- and Fibre-Rich Foods

Food 3D printing allows for the production of personalised foods in terms of shape and nutrition. In this study, we examined whether protein-, starch- and fibre-rich fractions extracted from faba beans can be combined to produce fibre- and protein-rich printable food inks for extrusion-based 3D printing. Small amplitude oscillatory shear measurements were used to characterise the inks while compression tests and scanning electron microscopy were used to characterise the freeze-dried samples. We found that rheological parameters such as storage modulus, loss tangent and yield stress were related to ink printability and shape stability. Investigations on the effect of ink composition, infill pattern (honeycomb/grid) and direction of compression on textural and microstructural properties of freeze-dried 3D-printed objects revealed no clear effect of infill pattern, but a strong effect of direction of compression. Microstructure heterogeneity seemed to be correlated with the textural properties of the printed objects.

3D Printing of Textured Soft Hybrid Meat Analogues

Meat analogue is a food product mainly made of plant proteins. It is considered to be a sustainable food and has gained a lot of interest in recent years. Hybrid meat is a next generation meat analogue prepared by the co-processing of both plant and animal protein ingredients at different ratios and is considered to be nutritionally superior to the currently available plant-only meat analogues. Three-dimensional (3D) printing technology is becoming increasingly popular in food processing. Three-dimensional food printing involves the modification of food structures, which leads to the creation of soft food. Currently, there is no available research on 3D printing of meat analogues. This study was carried out to create plant and animal protein-based formulations for 3D printing of hybrid meat analogues with soft textures. Pea protein isolate (PPI) and chicken mince were selected as the main plant protein and meat sources, respectively, for 3D printing tests. Then, rheology and forward extrusion tests were carried out on these selected samples to obtain a basic understanding of their potential printability. Afterwards, extrusion-based 3D printing was conducted to print a 3D chicken nugget shape. The addition of 20% chicken mince paste to PPI based paste achieved better printability and fibre structure.

Potato starch altered the rheological, printing, and melting properties of 3D-printable fat analogs based on inulin emulsion-filled gels

Plant-based oil inks that imitate the texture and melting behavior of traditional animal fats using 3D printing have been developed. The influence of the incorporation of potato starch and the type of oil on rheology and meltability was investigated. The results showed that the dynamic modulus and hardness of fat analogs increased, whereas fat analog meltability decreased with an increase in potato starch content. Coconut oil and soybean oil-containing fat analogs incorporated with proper potato starch levels exhibited good printability and similar meltability to commercial beef and pork fats. The addition of potato starch suppressed fat analog meltability as it disrupted the inulin matrix. Fat analogs containing coconut oil could be texturized at temperatures lower than those required for their soybean oil counterparts. The fat analogs were solid at room temperature, demonstrated good printability, and imitated the melting behavior of fat contained in real meat throughout the cooking process.

Determination of Material Requirements for 3D Gel Food Printing Using a Fused Deposition Modeling 3D Printer

The material requirements for printing gel food with a fused deposition modeling 3D printer were determined based on fidelity, shape retention, and extrudability, as described by the rheological parameters of storage modulus (G’), yield stress (τ₀), and phase angle (δ). The material requirements were determined for printing gel food using three formulations containing gelatin, gelatin and pectin, and gum mixture as the gelling agents. As compared with formulations based on gelatin alone, pectin-containing gelatin-based formulations yielded higher δ and lower G’ and τ₀ values, while gum mixture-based formulations formed a gel with higher G’ and δ values and a wider range of τ₀. Overall, this study presents quantitative material requirements for printing gel products containing gelatin, gelatin–pectin, and gum mixtures.

Insight into the correlations among rheological behaviour, protein molecular structure and 3D printability during the processing of surimi from golden pompano (Trachinotus ovatus)

To investigate the 3D printability of surimi from golden pompano, the rheological properties, protein molecular structure, and 3D printability of food inks from every step of surimi processing were measured, and their correlations were analysed. The results showed that surimi from chopping (surimi-C), chopping with salt (surimi-CS) and setting (surimi-S) were suitable for 3D printing, among which surimi-CS had the best shape fidelity. The clustering analysis of variables revealed that the yield stress and A_F could be used as indexes to characterize extrusion and deposition behaviour of surimi, respectively. The accuracy of 3D printing was affected by the extrusion property of the food ink, which was controlled by the ionic bond content. The stability of 3D printing was affected by the self-supporting capacity of the food ink, which was controlled by the hydrogen bond and hydrophobic interaction contents. The results provided theoretical guidance for developing 3D printing of surimi ingredients.

3D printing of a high protein yoghurt-based gel: Effect of protein enrichment and gelatine on physical and sensory properties

The potential application of 3D printing technology in creating protein-rich desserts with multisensory design was investigated. Yoghurt-gel inks were formulated by varying the concentration of gelatine and whey protein isolate (WPI). Assessment of rheological and textural properties prior to printing, showed that an increase of gelatine concentration from 7.5 to 12.5% w/w increased the yield stress, storage modulus, loss modulus, firmness, and resilience of yoghurt gels. Addition of 12% WPI reduced these effects; creating softer gels with reduced resilience. However, these gels showed stable shape after printing, especially in formulations with higher gelatine concentrations. The changes in textural properties caused by the extrusion process need to be considered when designing yoghurt gels, as a significant reduction in firmness and resilience and an increase in adhesiveness were observed after 3D printing. The more stable and well-shaped 3D printed yoghurt gels were obtained by the combined effect of WPI and gelatine which provided a good balance of appearance, taste, flavour, and mouthfeel attributes evaluated by a trained sensory panel. A consumer study performed with thirty healthy adults showed the potential to improve sensory acceptance through the creation of multisensory layered design.