Design of Functional Food Containing Encapsulated Bioactive Compounds Stabilized in a Psyllium–Potato Starch System

This research focused on the formulation of a health-oriented, clean-label food product fortified with encapsulated bioactive compounds from Sambucus nigra, Aronia melanocarpa, and Echinacea purpurea. To evaluate the protection of these sensitive compounds during production and storage, a comprehensive characterization was performed. This included basic physicochemical analyses, phenolic profiling, antioxidant activity tests, as well as rheological and textural measurements. Furthermore, sensory analysis, consumer evaluation, and microbiological stability during storage were assessed. Results from Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR) analyses confirmed the structural integrity of the capsules post-processing. Additionally, the application of a starch–psyllium carrier ensured that the textural and rheological properties remained fully comparable to the control sample, preventing undesirable matrix alterations. Specifically, product hardness (1.17–1.23 N) and adhesiveness (8.17–8.94 N·s) were maintained at stable levels, while color alterations were minor and likely noticeable only to trained observers (ΔE* < 3.2). Microbiological evaluation demonstrated that the application of different formulated products effectively inhibited the growth of Gram-positive and Gram-negative bacterial strains, with inhibition rates increasing from 3.4 to 39.7%. Collectively, the experimental data demonstrate that encapsulation is a highly effective strategy for fortifying fruit-based systems with sensitive extracts, successfully maximizing bioactivity retention while maintaining high product quality and sensory appeal.