Abstract
Eating and swallowing food are major challenges for the elderly with dysphagia. Three-dimensional (3D) food printing allows the creation of elderly food with nutrition, attractive shapes, and soft texture customizations. This study aimed to investigate the printability of soft-textured food (the mixture of chickpea protein isolate (CPI) with mealworm protein isolate (MPI) gel) by using single-nozzle printing (SNP) and coaxial printing (CoP) techniques. Artificial food boluses were prepared and their rheological properties were determined to understand safe swallowing. In the CoP system, extrusion pressure delivered alginate hydrogel (AH) as an outer fluid to support the structure of fragile food ink, resulting in printability and structural stability. Foods produced using the SNP technique exhibited printing failure. All printed foods exhibited a lower hardness value of ≤5 × 103 N/m2, corresponding to stage 4 of the universal design food (UDF) guideline. After oral food process simulation, the artificial CoP bolus showed significantly higher values of viscoelasticity, yield stress, and viscosity than the SNP and control boluses. This suggests a favorable cohesive bolus form that can prevent pulmonary aspiration during food swallowing. The CoP bolus displayed a denser microstructure due to the binding effect of the alginate molecules with positive electrolytes in the artificial saliva, which agreed with its higher rheological properties. This study successfully transformed unprintable soft food to be printable with an attractive 3D printing food shape using CoP technique as personalized food for the elderly. Additionally, this study provided insight into the relationship between bolus rheology and safe swallowing management.
| Original language | English |
|---|---|
| Article number | 102924 |
| Journal | Food Bioscience |
| Volume | 54 |
| DOIs | |
| Publication status | Published - 2023 Aug |
Bibliographical note
Funding Information:This study was supported by the collaborative research program between the University and the Rural Development Administration ( PJ01591202 ), Republic of Korea. This research was also supported by a grant from the Institute of Biomedical Science & Food Safety, Korea University, Republic of Korea .
Funding Information:
Surprisingly, the soft CPI-MPI paste had high printing resolution and structural quality when the coaxial 3D printing technique was used, as shown in Fig. 1C. In the CoP system, the extrusion pressure can simultaneously extrude and deposit double materials, food ink (inner fluid), and AH (outer fluid), and combine them into a core/sheath structure (Video S1). During the co-printing process, the outer AH flow provides sufficient gel strength and adherence modulation (Liu et al., 2022) and plays an essential role in physically encapsulating and supporting the fragile inner protein ink (Fig. S1). Moreover, this transparent envelope-like alginate gel was able to make the printed food attractive and unique by allowing for very smooth layers and a well-recognizable cylindrical 3D structure (Fig. 1C). After 10 min, the CoP food was able to maintain its shape without collapsing, suggesting that this complex multimaterial-containing CoP food achieved a new functional soft system. It also simultaneously improved mechanical strength, texture, and rheological properties because of its ability to hold food shape and resist dimensional deformation (Kim et al., 2021). This study revealed the possibility of printing soft food using the advanced CoP technique, transforming the unprintable soft CPI-MPI puree to have a visually stable appearance and structure.In the CoP system, the extrusion pressure can simultaneously extrude the food ink (inner fluid) and AH (outer fluid) and combine them into a core/sheath-encapsulated filament. In addition, AH with sufficient gel strength also played an essential role in physically supporting the fragile inner protein ink, resulting in good printing resolution and structural stability of the CoP food. On the other hand, foods produced by the SNP technique were unshapeable. CoP food exhibited a lower hardness value of ≤5 × 103 N/m2, corresponding to stage 4, which is suitable for the elderly with decreased masticatory efficiency and difficulty swallowing food according to the UDF guidelines. After mixing with SSF, artificial food boluses with significantly different rheological properties were obtained based on different printing techniques. The CoP bolus exhibited higher viscoelasticity, yield stress, and viscosity than the SNP and control boluses, suggesting a desired cohesive bolus form. This highly viscous bolus can delay the bolus flow rate to correct the esophagus tract and prevent pulmonary aspiration during swallowing in the elderly. The compact structure of the CoP bolus suggests that it has higher viscoelastic and indispensable properties. This study successfully unleashed unprintable soft food to be printable with visual appeal using 3D printing as a personalized food for the elderly and provided insight into the relationship of bolus rheology to ensure safe swallowing in elderly patients with dysphagia.This study was supported by the collaborative research program between the University and the Rural Development Administration (PJ01591202), Republic of Korea. This research was also supported by a grant from the Institute of Biomedical Science & Food Safety, Korea University, Republic of Korea.
Publisher Copyright:
© 2023
Keywords
- Alginate hydrogel
- Coaxial printing
- Elderly
- Food bolus
- Single-nozzle printing
- Universal design food
ASJC Scopus subject areas
- Food Science
- Biochemistry