Enrichment of Apple–Plum Fruit Mousse with Vitamin D3 and Sea Buckthorn Oil Using Pectin-Based Encapsulation: A Study of Physicochemical and Sensory Properties

The growing demand for 'clean label' functional foods necessitates the development of products that are not only health-promoting but also possess high sensory quality. Fruit mousses are an excellent matrix for fortification, appealing to a wide consumer base. This study aimed to enrich a conventional apple-plum mousse with vitamin D₃ and sea buckthorn oil, employing an encapsulation strategy based on endogenous fruit pectin. Three mousse variants were produced: a control (traditional), one fortified via the encapsulation of vitamin D₃ and sea buckthorn oil in a pectin-based nanoemulsion, and one fortified via the direct addition of the bioactive compounds. The products were analysed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), colorimetry, texture analysis, rheology, fatty acid profiling, and sensory evaluation (profiling and ranking). SEM and FTIR analyses confirmed the successful formation of spherical submicron capsules (approx. 100-300 nm) within the fortified mousse. Encapsulation resulted in significantly lower colour change (ΔE = 6.07 ± 0.03) compared to direct addition (ΔE = 11.16 ± 0.03). The fortified mousses exhibited approximately 16-20% lower hardness (0.21-0.22 N vs. 0.25 N) and threefold lower adhesiveness (0.06-0.08 N·s vs. 0.19 N·s) compared to the control. Rheological analysis indicated that fortification did not compromise the structural stability of the mousses (G' > G″ across 0.1-10 Hz). The fatty acid profile was significantly improved in the fortified variants, with a three-fold increase in linoleic acid (C18:2 n-6 c: from 16.90% to 55-56%) and the introduction of γ-linolenic acid (C18:3 n-6: 0.38-0.39%). Sensory ranking revealed no significant differences in overall quality between the control and fortified mousses (<i>p</i> > 0.05). Pectin present in fruits can be effectively utilised to encapsulate vitamin D₃ and sea buckthorn oil, allowing the successful development of a functional fruit mousse with an improved nutritional profile and retained sensory quality. Encapsulation proved to be a superior fortification method, offering better protection of bioactive compounds and a lesser impact on the product's original colour.