Thèse Extraction et Encapsulation de Phytochimiques Obtenus à Partir de Résidus Agro-Industriels Application Comme Additifs dans des Bases Alimentaires pour Impression 3D H/F Doctorat.Gouv.Fr

L'amidon se distingue comme un polysaccharide à faible coût, capable de former des gels
structurés, tandis que les protéines de lactosérum peuvent améliorer la valeur nutritionnelle et
moduler la texture des formulations. Par ailleurs, l'incorporation de pigments naturels issus de
fruits et de légumes peut renforcer l'attrait visuel et conférer des propriétés antioxydantes.

L'encapsulation représente une stratégie prometteuse pour incorporer et protéger ces
composés bioactifs pendant la transformation et le stockage, tandis que les fibres solubles
peuvent contribuer à la stabilité de la formulation et offrir des bienfaits prébiotiques. Une
évaluation sensorielle sera réalisée pour évaluer l'acceptabilité des aliments imprimés, en
considérant des attributs tels que la viscosité, la fermeté, la granularité, l'adhésivité, la vitesse
de dissolution et la persistance du film en bouche. Ces analyses compléteront les
caractérisations chimiques et physicochimiques utilisées pour optimiser les formulations.

Par conséquent, cette étude vise à développer des matrices alimentaires à base d'amidon et de
protéines de lactosérum, incorporant des fibres solubles et des pigments naturels encapsulés,
pour des applications d'impression 3D destinées aux patients souffrant de dysphagie. Les
formulations proposées seront conçues pour combiner des structures adaptées à la déglutition,
des performances d'impression, une acceptabilité sensorielle et l'incorporation stable de
composés bioactifs. 3D food printing emerges as an innovative and promising technology in the field of food engineering, enabling not only the customization of meals but also the sustainable utilization of by-products from the food industry. This additive manufacturing technique is based on the successive layer-by-layer deposition of food materials, formulated with appropriate rheological properties, to construct three-
dimensional objects with personalized shapes, textures, and compositions. Such an approach allows for the creation of visually appealing and sensory-adapted foods, which is particularly relevant for populations with specific nutritional needs or dietary restrictions (Seol et al., 2025; Wu; Zhu; Li, 2024).
In the context of dysphagia, a disorder characterized by difficulty in swallowing that can lead to malnutrition, muscle mass loss, and impaired quality of life, food texture plays a central role. The International Dysphagia Diet Standardization Initiative (IDDSI, 2019) establishes guidelines to classify foods and beverages according to their consistency, ensuring safety and suitability for individuals with this condition. In this scenario, 3D printing presents itself as a strategic tool for developing food matrices that meet IDDSI texture requirements while incorporating functional ingredients and bioactive compounds (Bitencourt et al., 2025).
The feasibility of this technique for such purposes critically depends on the development of functional food matrices that exhibit adequate rheological and structural properties for the extrusion process and post-deposition shape maintenance (Souza et al., 2025; Balabram et al., 2025). In this context, starch stands out as a low-cost, widely available polysaccharide capable of forming thermoreversible gels that confer excellent structuring to formulations (Sponchiado et al., 2025). Whey protein, in turn, can be incorporated to nutritionally enrich the matrices and modulate their texture, given its high nutritional quality, solubility, and ability to form protein networks that interact synergistically with starch chains (Guo et al., 2024; Li; Wang; Yang; Xiao, 2024). The combination of these two biopolymers can yield matrices with the firmness, cohesiveness, and stability required for 3D printing, ensuring the structural integrity of the produced foods.

Beyond structural aspects, the acceptance of printed food by the end consumer is strongly associated with its sensory characteristics and health appeal (Derossi et al., 2024). In this regard, the incorporation of natural pigments, such as anthocyanins present in grapes, shows promise not only for adding visual attractiveness to foods intended for dysphagia patients but also for conferring functionality to the formulation by incorporating bioactive compounds with antioxidant properties.
Concurrently, the addition of soluble fibers, such as those extracted from melon peel, can contribute to improving the stability of the food matrix, modulating nutrient release, and conferring prebiotic benefits to the formulation (Pimisa et al., 2024). The utilization of this agro-industrial residue, which is abundant and often discarded, confers a sustainable character to the proposal while enriching the final product with fibrous compounds beneficial to health. The adjustment of the flavor profile with natural sweeteners, such as stevia, complements the formulation, aiming to provide a balanced and pleasant sensory experience for the target population, an essential factor for adherence to dietary treatment.
In light of the above, this study aims to develop and characterize biopolymer-based food matrices, produced by 3D printing, intended for individuals with dysphagia, reduced appetite, or other conditions that compromise adequate food intake. The proposed formulation combines starch and whey protein as structural components, incorporating soluble fibers extracted from melon peel and natural pigments obtained from grapes and carrots. The study seeks to evaluate the effect of these components on the rheological properties of the formulations, the stability of the formed gels, printability (geometric fidelity during printing), and finally, texture adequacy according to the protocols established by IDDSI for foods intended for individuals with dysphagia. It is believed that this multifactorial approach can contribute to improving the nutritional status, eating pleasure, and well-being of individuals with dysphagia, aligning technological innovation, sustainability, and
nutrition. This project aims to investigate the relationships between the rheological, printing, instrumental textural, and sensory properties of selected starch and whey protein-based food matrices enriched with soluble fibers derived from passion fruit peel and natural pigments from grape and carrot, developed and initially characterized within the doctoral research in Brazil. The expected outcomes are to establish scientific relationships between instrumental measurements and sensory
perception, providing insights into the design of nutritionally enriched, visually attractive, and texture-tailored 3D-printed foods.
The specific objectives are to:
(i) Assess the rheological properties and printing performance of selected starch- and whey protein-based formulations under standardized experimental conditions at UMR SayFood, using newly prepared batches to minimize variability associated with differences in equipment, sample preparation, and analytical procedures between institutions.
(ii) Characterize the sensory properties of selected 3D-printed formulations through sensory evaluation, focusing on oral texture attributes relevant to food intake, including firmness, cohesiveness, adhesiveness, perceived viscosity, granularity, structural breakdown, and oral persistence. Instrumental textural properties will also be determined to support the interpretation of sensory responses;
(iii) Establish relationships between rheological behavior, printing performance, physicochemical and instrumental textural properties, and sensory perception through multivariate statistical analyses, identifying instrumental parameters associated with perceived oral texture. Particular emphasis will be placed on correlating instrumental measurements with sensory attributes using samples obtained from the same experimental batches prepared at UMR SayFood.