Formulation and characterisation of fruit- and vegetable-based gel/paste for potential application in food 3D printing

Chapter 1 2The food sector always explores new technologies to produce safe, healthy, delicious, and sustainable food products that fulfill the evolving needs of consumers.Personalized foods with customizable design, sensory properties, and nutritional value are attracting growing interests from both individuals and food manufacturers (Derossi et al., 2020).A personalized sensory experience can lead to wellbeing and enjoyment of various food products, while a personalized diet can potentially improve the nutritional intake and thus health.Producing personalized foods requires extensive understanding of food ingredient functionality, processing parameter optimizations, and automated production techniques that allow ondemand preparation.A flexible and autonomous production tool is therefore needed to achieve such production need, and among many technologies, 3D printing presents itself as an enabling method for such personalized food production (Derossi et al., 2021). 3D printing for food productionOver the past decades, 3D printing has matured into a rapid production technique in various manufacturing fields including aerospace, construction, and pharmaceutics.3D printing offers design flexibility and on-demand production that decouples manufacturing from large equipment and fixed production schedules.Among its applications, 3D food printing was first introduced by Periard et al. (2007) in the "Fab@Home" 3D printing model.The concept of a generalized 3D printer was developed to print a wide range of materials including foods based on the extrusion-based printing mechanism similar to 3D printing thermoplastics.Other than extrusion-based 3D printing, technologies such as powder-bed 3D printing also have been explored for food applications (Jonkers et al., 2020; Zhu et al., 2022).However, as its name suggests, powder-bed 3D printing produces food structures using powdered foods, which makes its application unfeasible with most non-powder food materials.Therefore, this thesis will focus on extrusion-based 3D food printing because of its popularity and compatibility to various food materials.To fabricate food structures using the extrusion-based 3D printing principle, food materials are generally first filled into a holding vessel such as a syringe, extruded through a small nozzle (with a typical diameter of 0.5 -2 mm), and then deposited onto a motorized platform to print a food structure layer-by-layer.The extrusion-based printing mechanism is intuitive and analogous to piping icing onto a cake.In the context of 3D printing, the "piping" action is automated with a syringe pump and a motorized stage.Generally, the Chapter 1 4 Advances and challenges of 3D food printingAfter experimenting with ready-to-print food materials, food technologists focused on formulating 3D printable food materials from various ingredients.For example, different food hydrocolloids (carrageenan, alginate, xanthan, etc.) have been used to formulate hydrogels and sometimes encapsulated systems for 3D food printing applications (Liu et al., 2019).Using hydrocolloids changes the rheological properties of food printing materials and improves the stability of 3D-printed food structures (Kim et al., 2018).Sensory evaluations of 3D-printed foods were also reported in various studies, to show the added values of using 3D printing.By customizing food designs, 3D-printed foods can provide unique sensory experiences by altering the texture and flavor perceptions of the consumers.Specific applications of 3D food printing emerged towards special consumer groups.3Dprinted foods are formulated and fabricated for patients with dysphagia to accommodate swallowing difficulties with soft and flowable food materials with an appealing appearance (Pant et al., 2021).Personalized snack bars were 3D-printed and served to Dutch military personnels as an exploratory study of on-demand food personalization (Caulier et al., 2020).Moreover, with the design flexibility in the food printing materials, functional materials have been prepared to achieve 4D printing applications of foods.On top of the 3 physical dimensions, time is here considered as the 4th dimension: 4D printed foods can show changes in color, shape, and mechanical behavior (Teng et al., 2021).Previous research focused on formulating suitable food printing material and developing prototypes of personalized 3D-printed foods (Derossi et al., 2021).These studies were often realized based on extensive trial-and-error experiments, which leads to excessive investment in time and raw materials.Minimal research effort has been devoted to automatically optimize 3D food printing parameters for a diverse range of food materials.Moreover, the performance of 3D food printing is often manually inspected by experienced operators, making it difficult to standardize and scale up to meet the growing demand of the market.The relatively inefficient operation of 3D food printing makes it challenging to establish streamlined production of personalized foods.Even with successful proof-ofconcept applications, 3D food printing at this moment still lacks the availability of robust software and hardware (i.e.3D printer, controller, and accessories) to achieve timely and accurate printing of foods that are ready for the consumer market.Chapter 2 Formulated food inks for extrusion-based 3D printing of personalized foods: A mini review

Application of three-dimensional (3D) printing is widely being applied from various fields of studies from mechanical manufacturing to civil constructions. Food is considered an essential factor for human survival. Modern day’s humans are considering food not only for survival but for other qualitative attributes and characteristic properties as well. With the development of 3D printing technologies, it is now possible to print with almost any kind of materials, including organics. This technological development had empowered the new generation food technologists/engineers to print almost all types of foods from chocolate to pizza, of desired characters, shape, size, color, texture, and other properties of interest. Foods with customized nutritional characteristics, lowered production price and processing time are various interesting applications of 3D printing for future foods. Decorated cakes and cookies and customized mobile-based 3D food printing applications, including the real-time printed picture of customers placing the food orders, make the future of food processing quite astonishing. 3D printing provides a wider platform for the food innovators to work more intensely on the new food product developments 52with much complex geometry that manually would be near to impossible. This chapter targets to provide information to the readers about various aspects of 3D printing in food processing, technological development for 3D food printing, and about different printable food component mixtures and recipes. Last part of the chapter discusses briefly the limitations and future scope of 3D food printing keeping in mind the future human needs and requirements.

Plant Based Ingredients to make edible inks for 3D food printing might help solve issues about food quality, food nutrition, and sustainability of food. We examine the molecular, functional, & nutritional characteristics of different plant proteins, plant Fibers & Hydrocolloids to determine their potential & their use as food industry. Additionally, we look at the possibilities of plant protein-based edible inks for 3D printing applications, where a material's form or other characteristics might alter over time to allow for precise issue profiles & texture modulations. Because of their superior structure-forming capabilities, and also their functional & nutritious qualities, Wheat gluten, pea protein, Lentil protein & soy proteins are frequently utilized as an ink for the 3D food printing applications. The use of 3D printing technology to create texture & improve probiotic & nutrient encapsulation in plant-based compositions was emphasized. Recent developments in 3D printing have been documented using edible smart materials that have been subjected to air-drying and microwaving processes. It was determined that the market sector for plant-based foods will be disrupted in three ways by 3D printing, Plant based meat, Personalized nutrition & Sustainability. This review addresses the latest developments in plant-based functional ingredients, or non-traditional food sources, that can be used as basis materials for 3D ink formulations & attention to the novel ingredients, their physiological role, and how their inclusion affects the product's rheological, structural, and printing qualities. 3D food printing has shown remarkable results in providing individualized nutrition and customized foods

The rapid advancement of 3D printing technology has extended its reach beyond traditional manufacturing and into the realm of gastronomy. This book chapter delves into the innovative world of 3D food printing and its transformative impact on the food industry. As a disruptive technology, 3D food printing holds the promise of revolutionizing how food is prepared, presented, and consumed. The chapter begins by providing an overview of 3D printing technology, outlining its principles and mechanisms that have been adapted to create intricate food structures. It discusses the various techniques and materials used in 3D food printing, including hydrocolloids, proteins, carbohydrates, and fats, each with their unique culinary applications. Furthermore, the chapter explores the key benefits of integrating 3D food printing into the culinary landscape. These benefits include enhanced customization, precise portion control, and the potential for addressing dietary restrictions and nutritional requirements. This technology also opens avenues for artistic expression in culinary arts, allowing chefs to push the boundaries of food aesthetics and presentation. The challenges and considerations associated with 3D food printing are thoroughly examined, such as the need to balance technological feasibility with maintaining the sensory qualities and flavours of traditional cuisine. Food safety and regulatory concerns are also addressed, emphasizing the importance of ensuring that 3D printed food products meet stringent standards. Real-world applications of 3D food printing within the food industry range from personalized nutrition and meal replacement solutions to sustainable food production practices.

Rheological property, β-carotene stability and 3D printing characteristic of whey protein isolate emulsion gels by adding different polysaccharides

Development of beetroot powder-enriched inks for 3D food printing based on hydrogel/oleogel bigels

The aim of this study was to explore the 3D printing ability of taro paste affected by five different food additives (sodium alginate [SA], sodium carboxymethyl cellulose, xanthan gum, guar gum, and whey protein). Rheological tests indicated that all samples showed shear‐thinning behavior and the apparent viscosity, storage modulus G′, and loss modulus G″ were all improved. The texture and moisture distribution were also affected by different additives. Samples added with SA exhibited the best performance on printing behavior with smooth outlook and less dimensional variability of printed cuboids (−0.76%, −0.60%, −0.50% in length, width, and height, respectively). Taking printing time and quality of printed cuboids into account, a nozzle diameter of 0.84 mm, a nozzle moving speed of 25 mm/s, and a extrusion rate of 13 mm3/s were considered to be the suitable parameters.Practical ApplicationsCompared with the normal food mixed system for 3D printing, the results indicated that taro–gum mixtures showed shear‐thinning behavior, apparent viscosity, printing behavior with smooth outlook, and less dimensional variability of printed cuboids were all improved, which is hopeful for further application in 3D food printing.

In this study, the effects of three hydrocolloids, xanthan gum (XG), arabica gum (AG) and carboxymethylcellulose (CMC), at two concentrations on the rheological, water mobility and 3D printing characteristics of pitaya fruit-based inks were investigated. The results showed that hydrocolloids restricted water mobility by increasing the immobilized water (T22) with higher content in CMC (97.5%−98.01%), AG (96.28%−97.26%), and XG (95.35%−95.38%), at 9 g/100 g than 6 g/100 g hydrocolloid concentration in the hydrocolloid-fruit inks. The rheological properties, based on the apparent viscosity, G′ and G′′ were increased in the pitaya fruit inks, especially in presence of CMC, then AG and XG at higher than lower concentration. Moreover, the printing precision improved, while the textural profile based on hardness and resilience increased, adhesiveness and springiness decreased, and influenced the color profiles in the hydrocolloid-fruit ink printed objects containing XG, then CMC and AG at 9 g/100 g than 6 g/100 g concentration. These changes were attributed to the increased water holding capacity in presence of different hydrocolloids at higher concentrations which reduced water mobility, slow water molecules re-orientation, and increased pseudoplastic and solid-like (G′ higher than G′′) character in the hydrocolloid-fruit inks: this could have led to the better retention of the 3D printed structure. The results presented demonstrated the influence of different types of hydrocolloids at varying concentrations on altering the physicochemical and technological properties of high moisture content fruit substrate-based inks for 3D food printing applications. In addition, these findings pave the way for further studies on the development of natural and health-promoting fruit substrate-based 3D printed snack food products.

Three-dimensional (3D) food printing (3DFP) is an emerging technology that enables the creation of personalized and functional foods by precisely controlling nutritional content and shape. This study investigated the 3D printability and rheological behavior of cereal-legume starch-based gels formulated with germinated brown rice (GBR) and red adzuki bean (RAB) flours, supplemented with xanthan and guar gums as functional additives. The physicochemical and structural properties of the gels were characterized through FT-IR, rheology, texture analysis, SEM, and sensory evaluation. In addition, the 3D printing fidelity, rheological behavior, color attributes, textural properties, microstructure, and sensory scoring of the printed products were evaluated. The results indicated that the gels exhibited pseudoplastic behavior, with the RABF/GBRF ratio of 1:2 (RG1:2) formulation showing optimal color properties (ΔE* = 0.60 ± 0.86) and the RABF/GBRF ratio of 2:1 (RG2:1) formulation demonstrating superior printing fidelity and structural stability (printing accuracy = 99.37 ± 0.39%). The gels' mechanical properties, such as hardness and chewiness, were significantly influenced by the RABF and GBRF ratios, with RG2:1 exhibiting the highest hardness (1066.74 ± 102.09) and RG1:2 showing the best springiness (0.64 ± 0.10). The sensory evaluation results indicated that the RABF/GBRF ratios of 1:1 (RG1:1) and RG1:2 had relatively high overall acceptance scores. These findings indicate that specific ratios of RABF and GBRF improve the 3D printability and textural properties of cereal-legume starch-based gels, enhancing their suitability for 3D food printing applications. This study provides valuable insights into the development of personalized and functional cereal-legume starch-based foods using 3DFP technology.

The main purpose of this paper is to explore the opportunities for fresh Nostoc sphaeroides (N. sphaeroides) to be applied to 3D food printing. N. sphaeroides is rich in nutrients and its paste possesses shear thinning properties. It was found the product obtained by 3D food printing with fresh N. sphaeroides had poor printability and was easy to collapse. In this study, we compared the addition of different potato starch (2%, 4%, 6% and 8%) to the characteristics of 3D printing of the N. sphaeroides gel system. The results obtained from the rheological analysis showed that the 6% potato starch added to of N. sphaeroides gel can be utilized for 3D food printing. The addition of potato starch increased the viscosity of the mixture so the printed lines were not easily broken, and the “self-supporting ability” of the material itself was enhanced to maintain a good shape without collapse. Texture profile analysis also showed that the 6% starch added printed product had the best gumminess parameter. In order to get a better printed product, the effects of printing parameters (nozzle diameter (Dn), extrusion rate (Vd) and nozzle moving speed (Vn)) on material printing performance and product formability was tested. When Dn, Vd, Vn were = 1.2 mm, 20 mm3/s, 25 mm/s, respectively, the printed product was having similar to the target product, with less breakage and less the changing of shape. Overall results show that 3D printing technology is a rising method for producing N. sphaeroides-based new products.

3D printing: Printing precision and application in food sector

Abstract3D food printing has far‐reaching potential in the food industry; however, consumer attitudes towards 3D food printing need to be evaluated. The present study investigated consumers' attitudes towards 3D food printing after consuming a cookie that was labeled as 3D printed. The participants (n = 133) first evaluated two cookies (conventional and “3D printed”) using hedonic scales and a check‐all‐that‐apply question. The participants were then asked to answer survey questions (7‐point Likert scale) and open‐ended comments about 3D printing. The results of the survey questions indicated that after consuming the “3D printed” cookie, the participants were willing to eat 3D printed foods and felt they were sustainable. The open‐ended comments highlighted some barriers to consumers' acceptance, including disgust, safety and unacceptability of 3D printed meat products. The findings illustrate that participants are less fearful of novel technologies if they have a positive experience with a food item produced by that technology.Practical applicationsA sensory trial (hedonic scales and check‐all‐that‐apply) was used as a priming step before asking participants about their attitudes towards 3D food printing. The participants' opinions were identified using quantitative (7‐point Likert scales) and qualitative (open‐ended comments) questions. The open‐ended comments allowed the participants to build on the responses they expressed with the Likert scales and identified other attitudes that were not included in the quantitative questions. Studies on consumer attitudes should include both quantitative and qualitative questions. The results indicated that if consumers have a positive experience with a 3D printed product (evaluated using hedonic scales), they have positive attitudes towards 3D printing. Additionally, the study highlighted for 3D food printing to be accepted by consumers; their concerns about safety and the unacceptability of 3D printed meat products need to be addressed.

Production of customized food through the insertion of a formulated nanoemulsion using coaxial 3D food printing

Design of multi-nozzle fixture and incorporation of various hydrocolloids to regulate 3D printing efficiency and anti-dysphagia properties of strawberry- pea protein isolate gels.

Modification strategies and multi-scene applications for plant proteins in 3D food printing: A review.