Utilization of kombucha residue for the production of nanocellulose and functional hydrogels containing free and nanostructured plant extract

Resumo

Bacterial cellulose, a type of nanocellulose (BNC) obtained from scoby, a by-product of the Kombucha fermentation process, represents a sustainable and high-value alternative to plant cellulose due to its high purity, mechanical strength and biocompatibility. This study aimed to optimize the purification process of the scoby to obtain cellulose and subsequently develop functional hydrogels based on nanocellulose incorporating olive leaf extract in its free and nanoencapsulated forms, to obtain a hydrogel with healing potential for therapeutic use in skin lesions. The scoby was subjected to a purification process and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In parallel, a nanoemulsion containing olive leaf extract was developed and physicochemically characterized in terms of particle size, polydispersity index, and zeta potential, and subsequently incorporated into nanocellulose-based hydrogels. The characterization of nanocellulose by SEM and XRD revealed a three-dimensional nanofibrillar morphology and a high degree of crystallinity. The nanoemulsion presented an average particle diameter of 164.2 nm, a polydispersity index of 0.21, and a zeta potential of -18.2 mV, parameters that indicate moderate colloidal stability and good particle size uniformity.. The hydrogels developed with the incorporation of the nanoemulsion and free extract exhibited good consistency, transparency, and water retention capacity, characteristics ideal for topical applications. It is concluded that BNC derived from scoby serves as a renewable biopolymer precursor for the development of functional healing hydrogels, combining sustainability, nanotechnology, and therapeutic efficacy.