306: 4D Printing of Dysphagia Foods Using Pea Protein and Purple Sweet Potato Flour

Introduction

Dysphagia, the difficulty in swallowing, is a prevalent issue among elderly people, causing various health problems. To address this challenge, dietary modifications towards softer and safer textures are necessary. However, these modified foods may compromise nutritional needs and visual appeal, diminishing their acceptance by consumers. While 3D printing offers shape customization, it falls short of fully satisfying the visual needs of dysphagia patients. Among sensory attributes, color significantly influences food choices. Anthocyanins, pigments found in purple sweet potatoes (PSP), exhibit color changes in response to specific environmental conditions, such as pH. This study investigates the application of 4D printing technology in developing nutritious, visually dynamic foods for dysphagia patients.

Methods

Food inks were prepared by mixing and heating PSP flour (13-21%), pea proteins (PP, 0-6%), and hydroxypropyl methylcellulose (HPMC, 0-0.6%) followed by the extrusion-based 3D printing. Texture Profile Analysis (TPA), small-strain rheological studies, Fourier Transform Infrared (FTIR) spectroscopy, and International Dysphagia Diet Standardization Initiative (IDDSI) tests were conducted to characterize the printed materials. The optimized formulation was assessed for 4D color-changing properties.

Results

Increasing PSP and PP concentrations enhanced viscosity and elastic modulus, while optimal printability required specific concentration ranges. Higher PP and HPMC concentrations promoted the formation of more hydrogen-bonding cross-linked networks, improving structural stability. The optimum formulation (17% PSP, 4% PP, and 0.2% HPMC) exhibited superior printing capabilities through pseudoplastic behavior and elastic properties crucial for printing and shape retention. This formulation demonstrated suitable dysphagia-specific attributes: hardness (74.16 g), cohesiveness (42.75%), adhesiveness (178.29 g×s), and gumminess (31.70 g). Additionally, the material exhibited responsive color changes in varying pH environments.

Significance

This study demonstrates the successful development of 4D-printed dysphagia foods combining nutritional value, appropriate texture, and dynamic color-changing properties. By optimizing PSP-based formulations, we created engaging, high-protein foods that meet both the textural requirements for safe swallowing and the sensory expectations of dysphagia patients, potentially improving their dining experience and nutritional intake.

Authors: Changhua Su, Yuchao Wu, Mengshi Lin, Bongkosh Vardhanabhuti