Food Grade Hydrogels Fabricated Using Hybrid Matrices as Carriers of Bioflavonoids Derived from 'Kinnow' Mandarin Peels.

Purpose: Fabrication of edible hydrogels envisaged as functional foods is the key objective of this work. A value addition in terms of utilization of a bioresource, 'kinnow' mandarin peels, by using its bioflavonoids (as polymethoxyflavone nanoparticles) impregnated into the hydrogels is aimed as a significant contribution in product development. Doing so would pave the way for further work on the study of release characteristics from the suitable matrix. The background of this work lies in the pre-systemic metabolism of flavonoids in the gastrointestinal tract. Finding a suitable matrix as a carrier of flavonoids to prevent this premature metabolism, thereby leading to a gastro-resistant edible hydrogel is the significance of this work. Methods: In present work, mono-hydrogels were prepared using casein by enzyme assisted gelation; and hybrid hydrogels were prepared from casein and alginate by electrostatically driven complexation method. Further, the fabricated hydrogels were tested for their rheological as well as mechanical properties. Also, the capacity of hydrogels to uphold the flavonoid poly-lactic-co-glycolic acid (PLGA) nanoparticles was investigated in terms of porosity measurements and morphological studies. Results: Gel behavior studies revealed shear thinning nature of hydrogels and a high resistance to deformation when subjected to a force. The hybrid hydrogels were found to have two key features, low porosity and appearance of hard lamellar structure, which ensured holding of flavonoid PLGA nanoparticles, as visualized by Cryo Scanning Electron Microscopy (Cryo-SEM) and Confocal Laser Scanning Microscope (CLSM). Conclusion: This work exemplifies biomass to biovalue conversion, thereby suggesting sustainable utilization of a bioresource. The double layered carrier system entrapping bioflavonoids is a step towards developing functional foods, as it forms a basis for understanding of the carrier systems vis-à-vis the intended application. [ABSTRACT FROM AUTHOR]