3D Food Printing Applications Related to Dysphagia: A Narrative Review

Biointerfacial supramolecular self-assembly of whey protein isolate nanofibrils on probiotic surface to enhance survival and application to 3D printing dysphagia foods

Personalized three-dimensional (3D) printed foods rich in probiotics were investigated. Lactiplantibacillus plantarum (Lp), as a representative of probiotics, was used to investigate the 3D printing of probiotic-rich dysphagia foods. Here, whey protein isolate nanofibrils (WPNFs) were coated and anchored on bacterial surfaces via biointerfacial supramolecular self-assembly, providing protection against environmental stress and the 3D printing process. The optimized composite gels consisting of High acyl gellan gum (0.25 g), whey protein isolate (1.25 g), fructooligosaccharides (0.75 g), Lp-WPNFs-Glyceryl tributyrate emulsion (Φ = 40%, 3.75 mL) can realize 3D printing, and exhibit high resolution, and stable shape. The viable cell count is higher than 8.0 log CFU/g. They are particularly suitable for people with dysphagia and are classified as level 5-minced & moist in the international dysphagia diet standardization initiative framework. The results provide new insights into the development of WPNFs-coating on bacterial surfaces to deliver probiotics and 3D printed food rich in probiotics.

Carboxymethylcellulose-induced depletion attraction to stabilize high internal phase Pickering emulsions for the elderly: 3D printing and β-carotene delivery

In this study, a carboxymethylcellulose (CMC) induced depletion attraction was developed to stabilize high internal phase Pickering emulsions (HIPPEs) as age-friendly 3D printing inks. The results demonstrated that depletion force induced the adsorption of yolk particles at the droplet interface and the formation of osmotic droplet clusters, thereby increasing the stability of HIPPEs. In addition, the rheological properties and nutrient delivery properties of HIPPEs could be adjusted by the mass ratio of yolk/CMC. The HIPPEs stabilized at yolk/CMC mass ratio 20:7.5 showed optimal printability, viscoelastic, structural recovery, and swallowability. HIPPEs have been applied to 3D printing, International Dysphagia Dietary Standardization Initiative (IDDSI) test, and in vitro digestive simulation in the elderly, indicating their attractive appearance, safe swallowability, and enhanced bioaccessibility of β-carotene. Our work provides new ideas for developing age-friendly foods with plasticity and nutrient delivery capacity by depletion attraction stabilizing HIPPEs.

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.

Personalized nutrition with 3D-printed foods: A systematic review on the impact of different additives

Three-dimensional (3D) printing is one of the world's top novel technologies in the food industry due to the production of food in different conditions and places (restaurants, homes, catering, schools, for dysphagia patients, and astronauts' food) and the production of personalized food. Nowadays, 3D printers are used in the main food industries, including meat, dairy, cereals, fruits, and vegetables, and have been able to produce successfully on a small scale. However, due to the expansion of this technology, it has challenges such as high-scale production, selection of printable food, formulation optimization, and food production according to the consumer's opinion. Food additives (gums, enzymes, proteins, starches, polyphenols, spices, probiotics, algae, edible insects, oils, salts, vitamins, flavors, and by-products) are one of the main components of the formulation that can be effective in food production according to the consumer's attitude. Food additives can have the highest impact on textural and sensory characteristics, which can be effective in improving consumer attitudes and reducing food neophobia. Most of the 3D-printed food cannot be printed without the presence of hydrocolloids, because the proper flow of the selected formulation is one of the key factors in improving the quality of the printed product. Functional additives such as probiotics can be useful for specific purposes and functional food production. Food personalization for specific diseases with 3D printing technology requires a change in the formulation, which is closely related to the selection of correct food additives. For example, the production of 3D-printed plant-based steaks is not possible without the presence of additives, or the production of food for dysphagia patients is possible in many cases by adding hydrocolloids. In general, additives can improve the textural, rheological, nutritional, and sensory characteristics of 3D printed foods; so, investigating the mechanism of the additives on all the characteristics of the printed product can provide a wide perspective for industrial production and future studies.

Pharmaceutical applications and requirements of resins for printing by digital light processing (DLP)

The digital light processing (DLP) printer has proven to be effective in biomedical and pharmaceutical applications, as its printing method does not induce shear and a strong temperature on the resin. In addition, the DLP printer has good resolution and print quality, which makes it possible to print complex structures with a customized shape, being used for various purposes ranging from jewelry application to biomedical and pharmaceutical areas. The big disadvantage of DLP is the lack of a biocompatible and non-toxic resin on the market. To overcome this limitation, an ideal resin for biomedical and pharmaceutical use is needed. The resin must have appropriate properties, so that the desired format is printed when with a determined wavelength is applied. Thus, the aim of this work is to bring the basic characteristics of the resins used by this printing method and the minimum requirements to start printing by DLP for pharmaceutical and biomedical applications. The DLP method has proven to be effective in obtaining pharmaceutical devices such as drug delivery systems. Furthermore, this technology allows the printing of devices of ideal size, shape and dosage, providing the patient with personalized treatment.

Pathways in formulating foods for the elderly

The growth of the elderly population worldwide is posing significant challenges to human society. The progressive physical and physiological changes occur with aging, including decreased appetite, incomplete digestion, and reduced absorption of nutrients. A common feature of many elderly people's diets is a deficiency in proteins (especially easily digestible ones) and micronutrients (e.g., vitamins, zinc, iron, and calcium). One of the solutions to this problem is the incorporation of these components into suitably texture-modified foods. There is a dearth of products that meet the needs of the elderly with special medical/health conditions such as dysphagia, osteoporosis, diabetes, and cardiovascular disease, as well as those who are in hospital and palliative care. Future research and development of foods for the elderly must address specific dietary needs of different subgroups of elderly people with underlying health conditions. The existence of different physical and physiological stages of the elderly means that their specific dietary requirements must be considered. This review summarizes current knowledge on nutritional requirements including those with underlying health problems and outlines the research and innovation pathways for developing new foods considering nutrition, texture, flavor, and other sensory aspects.

Different particle sizes of Momordica charantia leaf powder modify the rheological and textural properties of corn starch-based 3D food printing ink

The study determined the effect of incorporating Momordica charantia leaf powder (MCLP) into corn-starch 3D food-printing ink as a functional ingredient. The effects of the particle size (75, 131, and 200 μm) and quantity of MCLP on 3D printing performance, structural, textural, and rheological properties of corn starch gel were evaluated with different concentrations (5, 10, and 15 % (w/w)) of corn starch. The viscoelastic properties of food inks were determined considering their behavior during extrusion and self-recovery after printing. Scanning electron microscope was used to characterize the microstructure. Based on the results, a high starch content (15 %) with 5 % MCLP was more favorable for 3D food printing. In addition, 3D printing performance, textural and rheological properties of formulated ink was mainly governed by the particle size of MCLP. The food ink with a 5 % mass fraction of 200 μm MCLP had the highest printing precision and the best masticatory properties.

Evaluation of aspiration risk by relatives of inpatients in the neurology service: A metaphor analysis

BACKGROUND

The risk of aspiration is high in stroke patients due to dysphagia/loss of swallowing. This problem can cause problems affecting the nutrition of patients. Due to the possible risk of aspiration during feeding, patient relatives are hesitant to feed their patients. Because of this fear, malnutrition and hospital readmissions may increase. It is important to evaluate the fear of aspiration risk of relatives of patients hospitalized in the neurology service. The aim of this study is to determine the views of the relatives of patients treated in the neurology service about the risk of aspiration through metaphors.

METHOD

This article analyzed metaphors of patients' relatives' about the risk of aspiration. The analysis uses metaphor identification and analysis. The research sample consisted of 31 patients. First of all, in the study, evaluation of the data was conducted by performing content analysis, as a result of which it was divided into metaphors and conceptual categories, and the relevant field was associated with the text (event, thought, feelings, related in speech or writing). In the reporting of research, the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist was used.

RESULTS

It was seen that the patients' relatives produced 31 different metaphors in response to the statement 'Aspiration risk is like …, because it is …' The patients' relatives mostly compared the concept of 'fear of aspiration' to the concept of 'fear' (n: 24).

CONCLUSIONS

In this study, relatives mostly described the concept of fear related to the risk of aspiration. According to this result, patients' relatives have a great fear of aspiration increasing the risk of readmission to hospital and of malnutrition. This result shows that informing patients' relatives will increase awareness and will allow them to provide informed care.

PATIENT AND PUBLIC CONTRIBUTION

Collaborated with patients and their relatives regarding the risk of aspiration and contributed to the planning of care for the risk of aspiration.

Food Processing and Nutrition Strategies for Improving the Health of Elderly People with Dysphagia: A Review of Recent Developments

Dysphagia, or swallowing difficulty, is a common morbidity affecting 10% to 33% of the elderly population. Individuals with dysphagia can experience appetite, reduction, weight loss, and malnutrition as well as even aspiration, dehydration, and long-term healthcare issues. However, current therapies to treat dysphagia can routinely cause discomfort and pain to patients. To prevent these risks, a non-traumatic and effective treatment of diet modification for safe chewing and swallowing is urgently needed for the elderly. This review mainly summarizes the chewing and swallowing changes in the elderly, as well as important risk factors and potential consequences of dysphagia. In addition, three texture-modified food processing strategies to prepare special foods for the aged, as well as the current statuses and future trends of such foods, are discussed. Nonthermal food technologies, gelation, and 3D printing techniques have been developed to prepare soft, moist, and palatable texture-modified foods for chewing and swallowing safety in elderly individuals. In addition, flavor enhancement and nutrition enrichment are also considered to compensate for the loss of sensory experience and nutrients. Given the trend of population aging, multidisciplinary cooperation for dysphagia management should be a top priority.

Investigation of 3D printing product of powder-based white mushroom incorporated with soybean protein isolate as dysphagia diet

The elderly people are prone to dysphagia due to weakened muscle strength. 3D food printing could modify the nutritional ratio and shape design to produce personalized nutritious food suitable for patients with dysphagia. White mushroom (Agaricus bisporus) is rich in a variety of active ingredients such as polysaccharides and polyphenols which are beneficial to human body, but its unique texture is not suitable for patients with dysphagia to chew. This study investigated the impact of different concentrations of soybean protein isolate (SPI, 3%, 5%, 7%, w/w) on 3D food printing of white mushroom powder and carried out the hierarchical representation of dysphagia diet within the framework of International Dysphagia Diet Standardization Initiative (IDDSI). The results illustrated that SPI addition to white mushroom gel reduced water mobility and promoted hydrogen bond formation, which significantly improved the mechanical strength and cohesiveness of printing inks, including yield stress, viscosity and hardness. IDDSI tests showed that the SPI addition of 3% and 5% helped the printing ink pass the spoon tilt test and the fork drip test, which could be classified as level 5 minced and moist food under the consideration of the fork pressure test. The 3D printing results indicated that the 7% SPI addition made the yield stress too high and was not easy for extrusion, resulting in the appearance defects of the printed sample. The addition of 3% SPI could make the printed sample have smooth surface and excellent self-supporting capacity. This work provides insights of white mushroom 3D printing technology as a more visually appealing dysphagia diet.

Development and characterization of emulsion gels prepared via gliadin-based colloidal particles and gellan gum with tunable rheological properties for 3D printed dysphagia diet

Dysphagia, a condition characterized by difficulty swallowing, has emerged as a threat to health. Herein, we investigated the feasibility of preparing a novel 3D-printed dysphagia diet using emulsions and gellan gum. A gel network was facilitated by the inclusion of gellan gum, which also helped to reduce the size of the oil droplets. Emulsion gels (with 0.3 %-0.5 % gellan gum) were stable at 25 °C for 30 days and tolerated a high ionic concentration of 800 mmol L-1. Emulsion gels remained stable after heat treatment and centrifugation. The excellent stability of the emulsion gels was related to the three-dimensional network developed by the gellan gum. The rheological results validated the solid-state behavior, shear thinning behavior and structural recovery of emulsion gels. Emulsion gels with 0.3 %-0.5 % gellan gum were suitable for 3D printing since they had high printing accuracy, self-support, and smooth surface texture. International Diet Standardization Initiative (IDDIS) tests have shown that emulsion gels can be classified as a level 3-5 dysphagia diet. In addition, the bioaccessibility of astaxanthin increased 1.7 times after being encapsulated by emulsion gels. Overall, these results demonstrate the potential of emulsion gels in the development of novel 3D-printed diets for dysphagia and bioactive protection.

Challenges and Prospects of Plant-Protein-Based 3D Printing

Three-dimensional (3D) printing is a rapidly developing additive manufacturing technique consisting of the deposition of materials layer-by-layer to produce physical 3D structures. The technique offers unique opportunities to design and produce new products that cater to consumer experience and nutritional requirements. In the past two decades, a wide range of materials, especially plant-protein-based materials, have been documented for the development of personalized food owing to their nutritional and environmental benefits. Despite these benefits, 3D printing with plant-protein-based materials present significant challenges because there is a lack of a comprehensive study that takes into account the most relevant aspects of the processes involved in producing plant-protein-based printable items. This review takes into account the multi-dimensional aspects of processes that lead to the formulation of successful printable products which includes an understanding of rheological characteristics of plant proteins and 3D-printing parameters, as well as elucidating the appropriate concentration and structural hierarchy that are required to maintain stability of the substrate after printing. This review also highlighted the significant and most recent research on 3D food printing with a wide range of plant proteins. This review also suggests a future research direction of 3D printing with plant proteins.

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.

Three-Dimensional Printing of Foods: A Critical Review of the Present State in Healthcare Applications, and Potential Risks and Benefits

Three-dimensional printing is one of the most precise manufacturing technologies with a wide variety of applications. Three-dimensional food printing offers potential benefits for food production in terms of modifying texture, personalized nutrition, and adaptation to specific consumers' needs, among others. It could enable innovative and complex foods to be presented attractively, create uniquely textured foods tailored to patients with dysphagia, and support sustainability by reducing waste, utilizing by-products, and incorporating eco-friendly ingredients. Notable applications to date include, but are not limited to, printing novel shapes and complex geometries from candy, chocolate, or pasta, and bio-printed meats. The main challenges of 3D printing include nutritional quality and manufacturing issues. Currently, little research has explored the impact of 3D food printing on nutrient density, bioaccessibility/bioavailability, and the impact of matrix integrity loss on diet quality. The technology also faces challenges such as consumer acceptability, food safety and regulatory concerns. Possible adverse health effects due to overconsumption or the ultra-processed nature of 3D printed foods are major potential pitfalls. This review describes the state-of-the-art of 3D food printing technology from a nutritional perspective, highlighting potential applications and current limitations of this technology, and discusses the potential nutritional risks and benefits of 3D food printing.

Advances in the Potential Application of 3D Food Printing to Enhance Elderly Nutritional Dietary Intake

The contradiction between the growing demand from consumers for "nutrition & personalized" food and traditional industrialized food production has consistently been a problem in the elderly diet that researchers face and discuss. Three-dimensional (3D) food printing could potentially offer a solution to this problem. This article reviews the recent research on 3D food printing, mainly including the use of different sources of protein to improve the performance of food ink printing, high internal phase emulsion or oleogels as a fat replacement and nutrition delivery system, and functional active ingredients and the nutrition delivery system. In our opinion, 3D food printing is crucial for improving the appetite and dietary intake of the elderly. The critical obstacles of 3D-printed food for the elderly regarding energy supplements, nutrition balance, and even the customization of the recipe in a meal are discussed in this paper. By combining big data and artificial intelligence technology with 3D food printing, comprehensive, personalized, and customized geriatric foods, according to the individual traits of each elderly consumer, will be realized via food raw materials-appearance-processing methods. This article provides a theoretical basis and development direction for future 3D food printing for the elderly.

Easy-to-swallow mooncake using 3D printing: Effect of oil and hydrocolloid addition

3D printing is a promising technology for food production, capable of producing and developing personalized food products. In recent years, research on the application of 3D printing technology to create easy-to-swallow foods for the elderly with dysphagia has received extensive attention. In this study, we applied dual nozzle 3D printing technology to develop an easy-to-swallow mooncake food using a traditional Chinese food, mooncake, as a model system. We optimized the printing dough ink formulation by setting up soybean oil gradient experiments and Arabic gum gradient experiments, and then we applied the optimized dough ink as the crust of the mooncake to produce easy-to-swallow mooncakes. The experimental results show that the addition of 2.5 g of soybean oil and 0.125 g of Arabic gum could improve the texture of the dough product and reduce its hardness and adhesiveness. The mooncake produced with this crust dough ink was rated in the IDDSI texture level four, which met expectations. Therefore, this work provides insights into the development of easy-to-swallow food products.

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.

A Review of Food Texture Modification among Individuals with Cerebral Palsy: The Challenges among Cerebral Palsy Families

Individuals with cerebral palsy (CP) frequently present with multiple feeding problems, which may require food texture modification to ensure safe feeding. This review aims to explore the challenges individuals with CP and their caregiver's face and recommend modified food textures to ensure safety and improve the quality of life and nutritional status. A systematic search was carried out through four databases (i.e., EBSCO (Medline), PubMed, Science Direct, and Web of Science) between January 2011 and May 2022. Out of 86 articles retrieved, seven were selected based on keywords and seven other studies through manual search-five cross-sectional studies, two qualitative studies, one correlational study, one mixed method study, one case-control study, two sections of books, and two educational materials. The findings suggest that preparation and intake of food with modified texture play a necessary role in the safety of swallowing in addition to physical, social, and environmental aspects. Safety was found to be the crucial part of the food texture modification provision besides considering the stress of the caregivers and the nutritional status of individuals with CP. Currently, there are no standard guidelines available pertaining to food texture modification. This led to uncertainties in the dietary provision among caregivers, which may lead to undernourishment. Hence, standard guidelines relating to food texture modification that focuses on food preparation and menus with calorie and nutrient information are timely to be developed.