Formulation-Driven Rational Architectonic Design of Pomelo (Citrus maxima) Peel-Derived Lignocellulosic Fibre-Enriched Chewable Tablets: Spectroscopic and Morphological Characterization of Structure–Function Relationships

Dietary fibre deficiency remains a global nutritional concern, and the development of fibre-enriched functional foods is increasingly important. Fruit processing by-products, such as pomelo (Citrus maxima) peel, represent a sustainable source of dietary fibre with potential techno-functional applications. In this study, a fibre-enriched chewable tablet was developed using pomelo (Citrus maxima) peel fibre (CPF) as a functional ingredient and structural matrix. The formulation was prepared through direct compression and systematically evaluated in terms of powder flow behaviour, structural characteristics (FTIR, XRD, and SEM), hydration-related functionality, and tablet quality attributes. The CPF-based powder blend exhibited good flowability and compressibility, with an angle of repose of 26.62°, Carr’s index of 8.9%, and a Hausner ratio of 1.22, indicating suitability for tablet processing. Structural characterisation demonstrated the formation of a semi-crystalline matrix with a porous fibrous morphology. CPF incorporation significantly improved water-holding capacity (9.84 g/g) and oil-holding capacity (2.97 g/g), indicating enhanced hydration functionality. The developed tablets exhibited uniform weight (560 ± 9.5 mg), consistent dimensions, and acceptable disintegration behaviour (168 ± 15 s), demonstrating satisfactory physical quality. Overall, these findings suggest that pomelo peel fibre can be effectively utilised in chewable delivery systems, providing a feasible strategy for the valorisation of citrus by-products in functional food applications.